[bios] Add bin-x86_64-pcbios build platform

Move most arch/i386 files to arch/x86, and adjust the contents of the
Makefiles and the include/bits/*.h headers to reflect the new
locations.

This patch makes no substantive code changes, as can be seen using a
rename-aware diff (e.g. "git show -M5").

This patch does not make the pcbios platform functional for x86_64; it
merely allows it to compile without errors.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/x86/interface/pcbios/apm.c

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2013 Marin Hannache <ipxe@mareo.fr>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/**
+ * @file
+ *
+ * Advanced Power Management
+ *
+ */
+
+#include <errno.h>
+#include <realmode.h>
+#include <ipxe/reboot.h>
+
+/**
+ * Power off the computer using APM
+ *
+ * @ret rc		Return status code
+ */
+static int apm_poweroff ( void ) {
+	uint16_t apm_version;
+	uint16_t apm_signature;
+	uint16_t apm_flags;
+	uint16_t carry;
+
+	/* APM check */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x15\n\t"
+	                                   "adc %%edx,0\n\t" )
+	                       : "=a" ( apm_version ), "=b" ( apm_signature ),
+                                 "=c" ( apm_flags ), "=d" ( carry )
+	                       : "a" ( 0x5300 ), "b" ( 0x0000 ),
+				 "d" ( 0x0000 ) );
+	if ( carry ) {
+		DBG ( "APM not present\n" );
+		return -ENOTSUP;
+	}
+	if ( apm_signature != 0x504d ) { /* signature 'PM' */
+		DBG ( "APM not present\n" );
+		return -ENOTSUP;
+	}
+	if ( apm_version < 0x0101 ) { /* Need version 1.1+ */
+		DBG ( "APM 1.1+ not supported\n" );
+		return -ENOTSUP;
+	}
+	if ( ( apm_flags & 0x8 ) == 0x8 ) {
+		DBG ( "APM power management disabled\n" );
+		return -EPERM;
+	}
+	DBG2 ( "APM check completed\n" );
+
+	/* APM initialisation */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x15\n\t"
+	                                   "adc %%edx,0\n\t" )
+	                       : "=d" ( carry )
+	                       : "a" ( 0x5301 ), "b" ( 0x0000 ),
+	                         "d" ( 0x0000 ) );
+	if ( carry ) {
+		DBG ( "APM initialisation failed\n" );
+		return -EIO;
+	}
+	DBG2 ( "APM initialisation completed\n" );
+
+	/* Set APM driver version */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x15\n\t"
+	                                   "adc %%edx,0\n\t" )
+	                       : "=d" ( carry )
+	                       : "a" ( 0x530e ), "b" ( 0x0000 ),
+	                         "c" ( 0x0101 ), "d" ( 0x0000 ) );
+	if ( carry ) {
+		DBG ( "APM setting driver version failed\n" );
+		return -EIO;
+	}
+	DBG2 ( "APM driver version set\n" );
+
+	/* Setting power state to off */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x15\n\t"
+	                                   "adc %%edx,0\n\t" )
+	                       : "=d" ( carry )
+	                       : "a" ( 0x5307 ), "b" ( 0x0001 ),
+	                         "c" ( 0x0003 ), "d" ( 0x0000) );
+	if ( carry ) {
+		DBG ( "APM setting power state failed\n" );
+		return -ENOTTY;
+	}
+
+	/* Should never happen */
+	return -ECANCELED;
+}
+
+PROVIDE_REBOOT ( pcbios, poweroff, apm_poweroff );

src/arch/x86/interface/pcbios/basemem.c

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <realmode.h>
+#include <bios.h>
+#include <basemem.h>
+#include <ipxe/hidemem.h>
+
+/** @file
+ *
+ * Base memory allocation
+ *
+ */
+
+/**
+ * Set the BIOS free base memory counter
+ *
+ * @v new_fbms		New free base memory counter (in kB)
+ */
+void set_fbms ( unsigned int new_fbms ) {
+	uint16_t fbms = new_fbms;
+
+	/* Update the BIOS memory counter */
+	put_real ( fbms, BDA_SEG, BDA_FBMS );
+
+	/* Update our hidden memory region map */
+	hide_basemem();
+}

src/arch/x86/interface/pcbios/bios_console.c

@@ -0,0 +1,566 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <assert.h>
+#include <realmode.h>
+#include <bios.h>
+#include <biosint.h>
+#include <ipxe/console.h>
+#include <ipxe/ansiesc.h>
+#include <ipxe/keys.h>
+#include <ipxe/keymap.h>
+#include <ipxe/init.h>
+#include <config/console.h>
+
+#define ATTR_BOLD		0x08
+
+#define ATTR_FCOL_MASK		0x07
+#define ATTR_FCOL_BLACK		0x00
+#define ATTR_FCOL_BLUE		0x01
+#define ATTR_FCOL_GREEN		0x02
+#define ATTR_FCOL_CYAN		0x03
+#define ATTR_FCOL_RED		0x04
+#define ATTR_FCOL_MAGENTA	0x05
+#define ATTR_FCOL_YELLOW	0x06
+#define ATTR_FCOL_WHITE		0x07
+
+#define ATTR_BLINK		0x80
+
+#define ATTR_BCOL_MASK		0x70
+#define ATTR_BCOL_BLACK		0x00
+#define ATTR_BCOL_BLUE		0x10
+#define ATTR_BCOL_GREEN		0x20
+#define ATTR_BCOL_CYAN		0x30
+#define ATTR_BCOL_RED		0x40
+#define ATTR_BCOL_MAGENTA	0x50
+#define ATTR_BCOL_YELLOW	0x60
+#define ATTR_BCOL_WHITE		0x70
+
+#define ATTR_DEFAULT		ATTR_FCOL_WHITE
+
+/* Set default console usage if applicable */
+#if ! ( defined ( CONSOLE_PCBIOS ) && CONSOLE_EXPLICIT ( CONSOLE_PCBIOS ) )
+#undef CONSOLE_PCBIOS
+#define CONSOLE_PCBIOS ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
+#endif
+
+/** Current character attribute */
+static unsigned int bios_attr = ATTR_DEFAULT;
+
+/** Keypress injection lock */
+static uint8_t __text16 ( bios_inject_lock );
+#define bios_inject_lock __use_text16 ( bios_inject_lock )
+
+/** Vector for chaining to other INT 16 handlers */
+static struct segoff __text16 ( int16_vector );
+#define int16_vector __use_text16 ( int16_vector )
+
+/** Assembly wrapper */
+extern void int16_wrapper ( void );
+
+/**
+ * Handle ANSI CUP (cursor position)
+ *
+ * @v ctx		ANSI escape sequence context
+ * @v count		Parameter count
+ * @v params[0]		Row (1 is top)
+ * @v params[1]		Column (1 is left)
+ */
+static void bios_handle_cup ( struct ansiesc_context *ctx __unused,
+			      unsigned int count __unused, int params[] ) {
+	int cx = ( params[1] - 1 );
+	int cy = ( params[0] - 1 );
+
+	if ( cx < 0 )
+		cx = 0;
+	if ( cy < 0 )
+		cy = 0;
+
+	__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
+					   "int $0x10\n\t"
+					   "cli\n\t" )
+			       : : "a" ( 0x0200 ), "b" ( 1 ),
+			           "d" ( ( cy << 8 ) | cx ) );
+}
+
+/**
+ * Handle ANSI ED (erase in page)
+ *
+ * @v ctx		ANSI escape sequence context
+ * @v count		Parameter count
+ * @v params[0]		Region to erase
+ */
+static void bios_handle_ed ( struct ansiesc_context *ctx __unused,
+			     unsigned int count __unused,
+			     int params[] __unused ) {
+	/* We assume that we always clear the whole screen */
+	assert ( params[0] == ANSIESC_ED_ALL );
+
+	__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
+					   "int $0x10\n\t"
+					   "cli\n\t" )
+			       : : "a" ( 0x0600 ), "b" ( bios_attr << 8 ),
+				   "c" ( 0 ),
+				   "d" ( ( ( console_height - 1 ) << 8 ) |
+					 ( console_width - 1 ) ) );
+}
+
+/**
+ * Handle ANSI SGR (set graphics rendition)
+ *
+ * @v ctx		ANSI escape sequence context
+ * @v count		Parameter count
+ * @v params		List of graphic rendition aspects
+ */
+static void bios_handle_sgr ( struct ansiesc_context *ctx __unused,
+			      unsigned int count, int params[] ) {
+	static const uint8_t bios_attr_fcols[10] = {
+		ATTR_FCOL_BLACK, ATTR_FCOL_RED, ATTR_FCOL_GREEN,
+		ATTR_FCOL_YELLOW, ATTR_FCOL_BLUE, ATTR_FCOL_MAGENTA,
+		ATTR_FCOL_CYAN, ATTR_FCOL_WHITE,
+		ATTR_FCOL_WHITE, ATTR_FCOL_WHITE /* defaults */
+	};
+	static const uint8_t bios_attr_bcols[10] = {
+		ATTR_BCOL_BLACK, ATTR_BCOL_RED, ATTR_BCOL_GREEN,
+		ATTR_BCOL_YELLOW, ATTR_BCOL_BLUE, ATTR_BCOL_MAGENTA,
+		ATTR_BCOL_CYAN, ATTR_BCOL_WHITE,
+		ATTR_BCOL_BLACK, ATTR_BCOL_BLACK /* defaults */
+	};
+	unsigned int i;
+	int aspect;
+
+	for ( i = 0 ; i < count ; i++ ) {
+		aspect = params[i];
+		if ( aspect == 0 ) {
+			bios_attr = ATTR_DEFAULT;
+		} else if ( aspect == 1 ) {
+			bios_attr |= ATTR_BOLD;
+		} else if ( aspect == 5 ) {
+			bios_attr |= ATTR_BLINK;
+		} else if ( aspect == 22 ) {
+			bios_attr &= ~ATTR_BOLD;
+		} else if ( aspect == 25 ) {
+			bios_attr &= ~ATTR_BLINK;
+		} else if ( ( aspect >= 30 ) && ( aspect <= 39 ) ) {
+			bios_attr &= ~ATTR_FCOL_MASK;
+			bios_attr |= bios_attr_fcols[ aspect - 30 ];
+		} else if ( ( aspect >= 40 ) && ( aspect <= 49 ) ) {
+			bios_attr &= ~ATTR_BCOL_MASK;
+			bios_attr |= bios_attr_bcols[ aspect - 40 ];
+		}
+	}
+}
+
+/**
+ * Handle ANSI DECTCEM set (show cursor)
+ *
+ * @v ctx		ANSI escape sequence context
+ * @v count		Parameter count
+ * @v params		List of graphic rendition aspects
+ */
+static void bios_handle_dectcem_set ( struct ansiesc_context *ctx __unused,
+				      unsigned int count __unused,
+				      int params[] __unused ) {
+	uint8_t height;
+
+	/* Get character height */
+	get_real ( height, BDA_SEG, BDA_CHAR_HEIGHT );
+
+	__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
+					   "int $0x10\n\t"
+					   "cli\n\t" )
+			       : : "a" ( 0x0100 ),
+				   "c" ( ( ( height - 2 ) << 8 ) |
+					 ( height - 1 ) ) );
+}
+
+/**
+ * Handle ANSI DECTCEM reset (hide cursor)
+ *
+ * @v ctx		ANSI escape sequence context
+ * @v count		Parameter count
+ * @v params		List of graphic rendition aspects
+ */
+static void bios_handle_dectcem_reset ( struct ansiesc_context *ctx __unused,
+					unsigned int count __unused,
+					int params[] __unused ) {
+
+	__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
+					   "int $0x10\n\t"
+					   "cli\n\t" )
+			       : : "a" ( 0x0100 ), "c" ( 0x2000 ) );
+}
+
+/** BIOS console ANSI escape sequence handlers */
+static struct ansiesc_handler bios_ansiesc_handlers[] = {
+	{ ANSIESC_CUP, bios_handle_cup },
+	{ ANSIESC_ED, bios_handle_ed },
+	{ ANSIESC_SGR, bios_handle_sgr },
+	{ ANSIESC_DECTCEM_SET, bios_handle_dectcem_set },
+	{ ANSIESC_DECTCEM_RESET, bios_handle_dectcem_reset },
+	{ 0, NULL }
+};
+
+/** BIOS console ANSI escape sequence context */
+static struct ansiesc_context bios_ansiesc_ctx = {
+	.handlers = bios_ansiesc_handlers,
+};
+
+/**
+ * Print a character to BIOS console
+ *
+ * @v character		Character to be printed
+ */
+static void bios_putchar ( int character ) {
+	int discard_a, discard_b, discard_c;
+
+	/* Intercept ANSI escape sequences */
+	character = ansiesc_process ( &bios_ansiesc_ctx, character );
+	if ( character < 0 )
+		return;
+
+	/* Print character with attribute */
+	__asm__ __volatile__ ( REAL_CODE ( "pushl %%ebp\n\t" /* gcc bug */
+					   "sti\n\t"
+					   /* Skip non-printable characters */
+					   "cmpb $0x20, %%al\n\t"
+					   "jb 1f\n\t"
+					   /* Read attribute */
+					   "movb %%al, %%cl\n\t"
+					   "movb $0x08, %%ah\n\t"
+					   "int $0x10\n\t"
+					   "xchgb %%al, %%cl\n\t"
+					   /* Skip if attribute matches */
+					   "cmpb %%ah, %%bl\n\t"
+					   "je 1f\n\t"
+					   /* Set attribute */
+					   "movw $0x0001, %%cx\n\t"
+					   "movb $0x09, %%ah\n\t"
+					   "int $0x10\n\t"
+					   "\n1:\n\t"
+					   /* Print character */
+					   "xorw %%bx, %%bx\n\t"
+					   "movb $0x0e, %%ah\n\t"
+					   "int $0x10\n\t"
+					   "cli\n\t"
+					   "popl %%ebp\n\t" /* gcc bug */ )
+			       : "=a" ( discard_a ), "=b" ( discard_b ),
+			         "=c" ( discard_c )
+			       : "a" ( character ), "b" ( bios_attr ) );
+}
+
+/**
+ * Pointer to current ANSI output sequence
+ *
+ * While we are in the middle of returning an ANSI sequence for a
+ * special key, this will point to the next character to return.  When
+ * not in the middle of such a sequence, this will point to a NUL
+ * (note: not "will be NULL").
+ */
+static const char *bios_ansi_input = "";
+
+/** A BIOS key */
+struct bios_key {
+	/** Scancode */
+	uint8_t scancode;
+	/** Key code */
+	uint16_t key;
+} __attribute__ (( packed ));
+
+/** Mapping from BIOS scan codes to iPXE key codes */
+static const struct bios_key bios_keys[] = {
+	{ 0x53, KEY_DC },
+	{ 0x48, KEY_UP },
+	{ 0x50, KEY_DOWN },
+	{ 0x4b, KEY_LEFT },
+	{ 0x4d, KEY_RIGHT },
+	{ 0x47, KEY_HOME },
+	{ 0x4f, KEY_END },
+	{ 0x49, KEY_PPAGE },
+	{ 0x51, KEY_NPAGE },
+	{ 0x3f, KEY_F5 },
+	{ 0x40, KEY_F6 },
+	{ 0x41, KEY_F7 },
+	{ 0x42, KEY_F8 },
+	{ 0x43, KEY_F9 },
+	{ 0x44, KEY_F10 },
+	{ 0x85, KEY_F11 },
+	{ 0x86, KEY_F12 },
+};
+
+/**
+ * Get ANSI escape sequence corresponding to BIOS scancode
+ *
+ * @v scancode		BIOS scancode
+ * @ret ansi_seq	ANSI escape sequence, if any, otherwise NULL
+ */
+static const char * bios_ansi_seq ( unsigned int scancode ) {
+	static char buf[ 5 /* "[" + two digits + terminator + NUL */ ];
+	unsigned int key;
+	unsigned int terminator;
+	unsigned int n;
+	unsigned int i;
+	char *tmp = buf;
+
+	/* Construct ANSI escape sequence for scancode, if known */
+	for ( i = 0 ; i < ( sizeof ( bios_keys ) /
+			    sizeof ( bios_keys[0] ) ) ; i++ ) {
+
+		/* Look for matching scancode */
+		if ( bios_keys[i].scancode != scancode )
+			continue;
+
+		/* Construct escape sequence */
+		key = bios_keys[i].key;
+		n = KEY_ANSI_N ( key );
+		terminator = KEY_ANSI_TERMINATOR ( key );
+		*(tmp++) = '[';
+		if ( n )
+			tmp += sprintf ( tmp, "%d", n );
+		*(tmp++) = terminator;
+		*(tmp++) = '\0';
+		assert ( tmp <= &buf[ sizeof ( buf ) ] );
+		return buf;
+	}
+
+	DBG ( "Unrecognised BIOS scancode %02x\n", scancode );
+	return NULL;
+}
+
+/**
+ * Map a key
+ *
+ * @v character		Character read from console
+ * @ret character	Mapped character
+ */
+static int bios_keymap ( unsigned int character ) {
+	struct key_mapping *mapping;
+
+	for_each_table_entry ( mapping, KEYMAP ) {
+		if ( mapping->from == character )
+			return mapping->to;
+	}
+	return character;
+}
+
+/**
+ * Get character from BIOS console
+ *
+ * @ret character	Character read from console
+ */
+static int bios_getchar ( void ) {
+	uint16_t keypress;
+	unsigned int character;
+	const char *ansi_seq;
+
+	/* If we are mid-sequence, pass out the next byte */
+	if ( ( character = *bios_ansi_input ) ) {
+		bios_ansi_input++;
+		return character;
+	}
+
+	/* Do nothing if injection is in progress */
+	if ( bios_inject_lock )
+		return 0;
+
+	/* Read character from real BIOS console */
+	bios_inject_lock++;
+	__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
+					   "int $0x16\n\t"
+					   "cli\n\t" )
+			       : "=a" ( keypress )
+			       : "a" ( 0x1000 ), "m" ( bios_inject_lock ) );
+	bios_inject_lock--;
+	character = ( keypress & 0xff );
+
+	/* If it's a normal character, just map and return it */
+	if ( character && ( character < 0x80 ) )
+		return bios_keymap ( character );
+
+	/* Otherwise, check for a special key that we know about */
+	if ( ( ansi_seq = bios_ansi_seq ( keypress >> 8 ) ) ) {
+		/* Start of escape sequence: return ESC (0x1b) */
+		bios_ansi_input = ansi_seq;
+		return 0x1b;
+	}
+
+	return 0;
+}
+
+/**
+ * Check for character ready to read from BIOS console
+ *
+ * @ret True		Character available to read
+ * @ret False		No character available to read
+ */
+static int bios_iskey ( void ) {
+	unsigned int discard_a;
+	unsigned int flags;
+
+	/* If we are mid-sequence, we are always ready */
+	if ( *bios_ansi_input )
+		return 1;
+
+	/* Do nothing if injection is in progress */
+	if ( bios_inject_lock )
+		return 0;
+
+	/* Otherwise check the real BIOS console */
+	bios_inject_lock++;
+	__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
+					   "int $0x16\n\t"
+					   "pushfw\n\t"
+					   "popw %w0\n\t"
+					   "cli\n\t" )
+			       : "=R" ( flags ), "=a" ( discard_a )
+			       : "a" ( 0x1100 ), "m" ( bios_inject_lock ) );
+	bios_inject_lock--;
+	return ( ! ( flags & ZF ) );
+}
+
+/** BIOS console */
+struct console_driver bios_console __console_driver = {
+	.putchar = bios_putchar,
+	.getchar = bios_getchar,
+	.iskey = bios_iskey,
+	.usage = CONSOLE_PCBIOS,
+};
+
+/**
+ * Inject keypresses
+ *
+ * @v ix86		Registers as passed to INT 16
+ */
+static __asmcall void bios_inject ( struct i386_all_regs *ix86 ) {
+	unsigned int discard_a;
+	unsigned int scancode;
+	unsigned int i;
+	uint16_t keypress;
+	int key;
+
+	/* If this is a blocking call, then loop until the
+	 * non-blocking variant of the call indicates that a keypress
+	 * is available.  Do this without acquiring the injection
+	 * lock, so that injection may take place.
+	 */
+	if ( ( ix86->regs.ah & ~0x10 ) == 0x00 ) {
+		__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
+						   "\n1:\n\t"
+						   "pushw %%ax\n\t"
+						   "int $0x16\n\t"
+						   "popw %%ax\n\t"
+						   "jc 2f\n\t"
+						   "jz 1b\n\t"
+						   "\n2:\n\t"
+						   "cli\n\t" )
+				       : "=a" ( discard_a )
+				       : "a" ( ix86->regs.eax | 0x0100 ),
+					 "m" ( bios_inject_lock ) );
+	}
+
+	/* Acquire injection lock */
+	bios_inject_lock++;
+
+	/* Check for keypresses */
+	if ( iskey() ) {
+
+		/* Get key */
+		key = getkey ( 0 );
+
+		/* Reverse internal CR->LF mapping */
+		if ( key == '\n' )
+			key = '\r';
+
+		/* Convert to keypress */
+		keypress = ( ( key << 8 ) | key );
+
+		/* Handle special keys */
+		if ( key >= KEY_MIN ) {
+			for ( i = 0 ; i < ( sizeof ( bios_keys ) /
+					    sizeof ( bios_keys[0] ) ) ; i++ ) {
+				if ( bios_keys[i].key == key ) {
+					scancode = bios_keys[i].scancode;
+					keypress = ( scancode << 8 );
+					break;
+				}
+			}
+		}
+
+		/* Inject keypress */
+		DBGC ( &bios_console, "BIOS injecting keypress %04x\n",
+		       keypress );
+		__asm__ __volatile__ ( REAL_CODE ( "int $0x16\n\t" )
+				       : "=a" ( discard_a )
+				       : "a" ( 0x0500 ), "c" ( keypress ),
+					 "m" ( bios_inject_lock ) );
+	}
+
+	/* Release injection lock */
+	bios_inject_lock--;
+}
+
+/**
+ * Start up keypress injection
+ *
+ */
+static void bios_inject_startup ( void ) {
+
+	/* Assembly wrapper to call bios_inject() */
+	__asm__ __volatile__ (
+		TEXT16_CODE ( "\nint16_wrapper:\n\t"
+			      "pushfw\n\t"
+			      "cmpb $0, %%cs:bios_inject_lock\n\t"
+			      "jnz 1f\n\t"
+			      "pushl %0\n\t"
+			      "pushw %%cs\n\t"
+			      "call prot_call\n\t"
+			      "addw $4, %%sp\n\t"
+			      "\n1:\n\t"
+			      "popfw\n\t"
+			      "ljmp *%%cs:int16_vector\n\t" )
+		: : "i" ( bios_inject ) );
+
+	/* Hook INT 16 */
+	hook_bios_interrupt ( 0x16, ( ( intptr_t ) int16_wrapper ),
+			      &int16_vector );
+}
+
+/**
+ * Shut down keypress injection
+ *
+ * @v booting		System is shutting down for OS boot
+ */
+static void bios_inject_shutdown ( int booting __unused ) {
+
+	/* Unhook INT 16 */
+	unhook_bios_interrupt ( 0x16, ( ( intptr_t ) int16_wrapper ),
+				&int16_vector );
+}
+
+/** Keypress injection startup function */
+struct startup_fn bios_inject_startup_fn __startup_fn ( STARTUP_NORMAL ) = {
+	.startup = bios_inject_startup,
+	.shutdown = bios_inject_shutdown,
+};

src/arch/x86/interface/pcbios/bios_nap.c

@@ -0,0 +1,16 @@
+#include <ipxe/nap.h>
+#include <realmode.h>
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/**
+ * Save power by halting the CPU until the next interrupt
+ *
+ */
+static void bios_cpu_nap ( void ) {
+	__asm__ __volatile__ ( "sti\n\t"
+			       "hlt\n\t"
+			       "cli\n\t" );
+}
+
+PROVIDE_NAP ( pcbios, cpu_nap, bios_cpu_nap );

src/arch/x86/interface/pcbios/bios_reboot.c

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * Standard PC-BIOS reboot mechanism
+ *
+ */
+
+#include <ipxe/reboot.h>
+#include <realmode.h>
+#include <bios.h>
+
+/**
+ * Reboot system
+ *
+ * @v warm		Perform a warm reboot
+ */
+static void bios_reboot ( int warm ) {
+	uint16_t flag;
+
+	/* Configure BIOS for cold/warm reboot */
+	flag = ( warm ? BDA_REBOOT_WARM : 0 );
+	put_real ( flag, BDA_SEG, BDA_REBOOT );
+
+	/* Jump to system reset vector */
+	__asm__ __volatile__ ( REAL_CODE ( "ljmp $0xf000, $0xfff0" ) : : );
+}
+
+PROVIDE_REBOOT ( pcbios, reboot, bios_reboot );

src/arch/x86/interface/pcbios/bios_smbios.c

@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <ipxe/uaccess.h>
+#include <ipxe/smbios.h>
+#include <realmode.h>
+#include <pnpbios.h>
+
+/** @file
+ *
+ * System Management BIOS
+ *
+ */
+
+/**
+ * Find SMBIOS
+ *
+ * @v smbios		SMBIOS entry point descriptor structure to fill in
+ * @ret rc		Return status code
+ */
+static int bios_find_smbios ( struct smbios *smbios ) {
+	struct smbios_entry entry;
+	int rc;
+
+	/* Scan through BIOS segment to find SMBIOS entry point */
+	if ( ( rc = find_smbios_entry ( real_to_user ( BIOS_SEG, 0 ), 0x10000,
+					&entry ) ) != 0 )
+		return rc;
+
+	/* Fill in entry point descriptor structure */
+	smbios->address = phys_to_user ( entry.smbios_address );
+	smbios->len = entry.smbios_len;
+	smbios->count = entry.smbios_count;
+	smbios->version = SMBIOS_VERSION ( entry.major, entry.minor );
+
+	return 0;
+}
+
+PROVIDE_SMBIOS ( pcbios, find_smbios, bios_find_smbios );

src/arch/x86/interface/pcbios/bios_timer.c

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * BIOS timer
+ *
+ */
+
+#include <ipxe/timer.h>
+#include <realmode.h>
+#include <bios.h>
+
+/**
+ * Get current system time in ticks
+ *
+ * @ret ticks		Current time, in ticks
+ *
+ * Use direct memory access to BIOS variables, longword 0040:006C
+ * (ticks today) and byte 0040:0070 (midnight crossover flag) instead
+ * of calling timeofday BIOS interrupt.
+ */
+static unsigned long bios_currticks ( void ) {
+	static int days = 0;
+	uint32_t ticks;
+	uint8_t midnight;
+
+	/* Re-enable interrupts so that the timer interrupt can occur */
+	__asm__ __volatile__ ( "sti\n\t"
+			       "nop\n\t"
+			       "nop\n\t"
+			       "cli\n\t" );
+
+	get_real ( ticks, BDA_SEG, 0x006c );
+	get_real ( midnight, BDA_SEG, 0x0070 );
+
+	if ( midnight ) {
+		midnight = 0;
+		put_real ( midnight, BDA_SEG, 0x0070 );
+		days += 0x1800b0;
+	}
+
+	return ( days + ticks );
+}
+
+PROVIDE_TIMER_INLINE ( pcbios, udelay );
+PROVIDE_TIMER ( pcbios, currticks, bios_currticks );
+PROVIDE_TIMER_INLINE ( pcbios, ticks_per_sec );

src/arch/x86/interface/pcbios/biosint.c

@@ -0,0 +1,119 @@
+#include <errno.h>
+#include <realmode.h>
+#include <biosint.h>
+
+/**
+ * @file BIOS interrupts
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/**
+ * Hook INT vector
+ *
+ * @v interrupt		INT number
+ * @v handler		Offset within .text16 to interrupt handler
+ * @v chain_vector	Vector for chaining to previous handler
+ *
+ * Hooks in an i386 INT handler.  The handler itself must reside
+ * within the .text16 segment.  @c chain_vector will be filled in with
+ * the address of the previously-installed handler for this interrupt;
+ * the handler should probably exit by ljmping via this vector.
+ */
+void hook_bios_interrupt ( unsigned int interrupt, unsigned int handler,
+			   struct segoff *chain_vector ) {
+	struct segoff vector = {
+		.segment = rm_cs,
+		.offset = handler,
+	};
+
+	DBG ( "Hooking INT %#02x to %04x:%04x\n",
+	      interrupt, rm_cs, handler );
+
+	if ( ( chain_vector->segment != 0 ) ||
+	     ( chain_vector->offset != 0 ) ) {
+		/* Already hooked; do nothing */
+		DBG ( "...already hooked\n" );
+		return;
+	}
+
+	copy_from_real ( chain_vector, 0, ( interrupt * 4 ),
+			 sizeof ( *chain_vector ) );
+	DBG ( "...chaining to %04x:%04x\n",
+	      chain_vector->segment, chain_vector->offset );
+	if ( DBG_LOG ) {
+		char code[64];
+		copy_from_real ( code, chain_vector->segment,
+				 chain_vector->offset, sizeof ( code ) );
+		DBG_HDA ( *chain_vector, code, sizeof ( code ) );
+	}
+
+	copy_to_real ( 0, ( interrupt * 4 ), &vector, sizeof ( vector ) );
+	hooked_bios_interrupts++;
+}
+
+/**
+ * Unhook INT vector
+ *
+ * @v interrupt		INT number
+ * @v handler		Offset within .text16 to interrupt handler
+ * @v chain_vector	Vector containing address of previous handler
+ *
+ * Unhooks an i386 interrupt handler hooked by hook_i386_vector().
+ * Note that this operation may fail, if some external code has hooked
+ * the vector since we hooked in our handler.  If it fails, it means
+ * that it is not possible to unhook our handler, and we must leave it
+ * (and its chaining vector) resident in memory.
+ */
+int unhook_bios_interrupt ( unsigned int interrupt, unsigned int handler,
+			    struct segoff *chain_vector ) {
+	struct segoff vector;
+
+	DBG ( "Unhooking INT %#02x from %04x:%04x\n",
+	      interrupt, rm_cs, handler );
+
+	copy_from_real ( &vector, 0, ( interrupt * 4 ), sizeof ( vector ) );
+	if ( ( vector.segment != rm_cs ) || ( vector.offset != handler ) ) {
+		DBG ( "...cannot unhook; vector points to %04x:%04x\n",
+		      vector.segment, vector.offset );
+		return -EBUSY;
+	}
+
+	DBG ( "...restoring to %04x:%04x\n",
+	      chain_vector->segment, chain_vector->offset );
+	copy_to_real ( 0, ( interrupt * 4 ), chain_vector,
+		       sizeof ( *chain_vector ) );
+
+	chain_vector->segment = 0;
+	chain_vector->offset = 0;
+	hooked_bios_interrupts--;
+	return 0;
+}
+
+/**
+ * Dump changes to interrupt vector table (for debugging)
+ *
+ */
+void check_bios_interrupts ( void ) {
+	static struct segoff vectors[256];
+	static uint8_t initialised;
+	struct segoff vector;
+	unsigned int i;
+
+	/* Print any changed interrupt vectors */
+	for ( i = 0; i < ( sizeof ( vectors ) / sizeof ( vectors[0] ) ); i++ ) {
+		copy_from_real ( &vector, 0, ( i * sizeof ( vector ) ),
+				 sizeof ( vector ) );
+		if ( memcmp ( &vector, &vectors[i], sizeof ( vector ) ) == 0 )
+			continue;
+		if ( initialised ) {
+			dbg_printf ( "INT %02x changed %04x:%04x => "
+				     "%04x:%04x\n", i, vectors[i].segment,
+				     vectors[i].offset, vector.segment,
+				     vector.offset );
+		}
+		memcpy ( &vectors[i], &vector, sizeof ( vectors[i] ) );
+	}
+	initialised = 1;
+}

src/arch/x86/interface/pcbios/e820mangler.S

@@ -0,0 +1,589 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL )
+
+	.text
+	.arch i386
+	.code16
+
+#define SMAP 0x534d4150
+
+/* Most documentation refers to the E820 buffer as being 20 bytes, and
+ * the API makes it perfectly legitimate to pass only a 20-byte buffer
+ * and expect to get valid data.  However, some morons at ACPI decided
+ * to extend the data structure by adding an extra "extended
+ * attributes" field and by including critical information within this
+ * field, such as whether or not the region is enabled.  A caller who
+ * passes in only a 20-byte buffer therefore risks getting very, very
+ * misleading information.
+ *
+ * I have personally witnessed an HP BIOS that returns a value of
+ * 0x0009 in the extended attributes field.  If we don't pass this
+ * value through to the caller, 32-bit WinPE will die, usually with a
+ * PAGE_FAULT_IN_NONPAGED_AREA blue screen of death.
+ *
+ * Allow a ridiculously large maximum value (64 bytes) for the E820
+ * buffer as a guard against insufficiently creative idiots in the
+ * future.
+ */
+#define E820MAXSIZE	64
+
+/****************************************************************************
+ *
+ * Allowed memory windows
+ *
+ * There are two ways to view this list.  The first is as a list of
+ * (non-overlapping) allowed memory regions, sorted by increasing
+ * address.  The second is as a list of (non-overlapping) hidden
+ * memory regions, again sorted by increasing address.  The second
+ * view is offset by half an entry from the first: think about this
+ * for a moment and it should make sense.
+ *
+ * xxx_memory_window is used to indicate an "allowed region"
+ * structure, hidden_xxx_memory is used to indicate a "hidden region"
+ * structure.  Each structure is 16 bytes in length.
+ *
+ ****************************************************************************
+ */
+	.section ".data16", "aw", @progbits
+	.align 16
+	.globl hidemem_base
+	.globl hidemem_umalloc
+	.globl hidemem_textdata
+memory_windows:
+base_memory_window:	.long 0x00000000, 0x00000000 /* Start of memory */
+
+hidemem_base:		.long 0x000a0000, 0x00000000 /* Changes at runtime */
+ext_memory_window:	.long 0x000a0000, 0x00000000 /* 640kB mark */
+
+hidemem_umalloc:	.long 0xffffffff, 0xffffffff /* Changes at runtime */
+			.long 0xffffffff, 0xffffffff /* Changes at runtime */
+
+hidemem_textdata:	.long 0xffffffff, 0xffffffff /* Changes at runtime */
+			.long 0xffffffff, 0xffffffff /* Changes at runtime */
+
+			.long 0xffffffff, 0xffffffff /* End of memory */
+memory_windows_end:
+
+/****************************************************************************
+ * Truncate region to memory window
+ *
+ * Parameters:
+ *  %edx:%eax	Start of region
+ *  %ecx:%ebx	Length of region
+ *  %si		Memory window
+ * Returns:
+ *  %edx:%eax	Start of windowed region
+ *  %ecx:%ebx	Length of windowed region
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+window_region:
+	/* Convert (start,len) to (start, end) */
+	addl	%eax, %ebx
+	adcl	%edx, %ecx
+	/* Truncate to window start */
+	cmpl	4(%si), %edx
+	jne	1f
+	cmpl	0(%si), %eax
+1:	jae	2f
+	movl	4(%si), %edx
+	movl	0(%si), %eax
+2:	/* Truncate to window end */
+	cmpl	12(%si), %ecx
+	jne	1f
+	cmpl	8(%si), %ebx
+1:	jbe	2f
+	movl	12(%si), %ecx
+	movl	8(%si), %ebx
+2:	/* Convert (start, end) back to (start, len) */
+	subl	%eax, %ebx
+	sbbl	%edx, %ecx
+	/* If length is <0, set length to 0 */
+	jae	1f
+	xorl	%ebx, %ebx
+	xorl	%ecx, %ecx
+	ret
+	.size	window_region, . - window_region
+
+/****************************************************************************
+ * Patch "memory above 1MB" figure
+ *
+ * Parameters:
+ *  %ax		Memory above 1MB, in 1kB blocks
+ * Returns:
+ *  %ax		Modified memory above 1M in 1kB blocks
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+patch_1m:
+	pushal
+	/* Convert to (start,len) format and call truncate */
+	xorl	%ecx, %ecx
+	movzwl	%ax, %ebx
+	shll	$10, %ebx
+	xorl	%edx, %edx
+	movl	$0x100000, %eax
+	movw	$ext_memory_window, %si
+	call	window_region
+	/* Convert back to "memory above 1MB" format and return via %ax */
+	pushfw
+	shrl	$10, %ebx
+	popfw
+	movw	%sp, %bp
+	movw	%bx, 28(%bp)
+	popal
+	ret
+	.size patch_1m, . - patch_1m
+
+/****************************************************************************
+ * Patch "memory above 16MB" figure
+ *
+ * Parameters:
+ *  %bx		Memory above 16MB, in 64kB blocks
+ * Returns:
+ *  %bx		Modified memory above 16M in 64kB blocks
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+patch_16m:
+	pushal
+	/* Convert to (start,len) format and call truncate */
+	xorl	%ecx, %ecx
+	shll	$16, %ebx
+	xorl	%edx, %edx
+	movl	$0x1000000, %eax
+	movw	$ext_memory_window, %si
+	call	window_region
+	/* Convert back to "memory above 16MB" format and return via %bx */
+	pushfw
+	shrl	$16, %ebx
+	popfw
+	movw	%sp, %bp
+	movw	%bx, 16(%bp)
+	popal
+	ret
+	.size patch_16m, . - patch_16m
+
+/****************************************************************************
+ * Patch "memory between 1MB and 16MB" and "memory above 16MB" figures
+ *
+ * Parameters:
+ *  %ax		Memory between 1MB and 16MB, in 1kB blocks
+ *  %bx		Memory above 16MB, in 64kB blocks
+ * Returns:
+ *  %ax		Modified memory between 1MB and 16MB, in 1kB blocks
+ *  %bx		Modified memory above 16MB, in 64kB blocks
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+patch_1m_16m:
+	call	patch_1m
+	call	patch_16m
+	/* If 1M region is no longer full-length, kill off the 16M region */
+	cmpw	$( 15 * 1024 ), %ax
+	je	1f
+	xorw	%bx, %bx
+1:	ret
+	.size patch_1m_16m, . - patch_1m_16m
+
+/****************************************************************************
+ * Get underlying e820 memory region to underlying_e820 buffer
+ *
+ * Parameters:
+ *   As for INT 15,e820
+ * Returns:
+ *   As for INT 15,e820
+ *
+ * Wraps the underlying INT 15,e820 call so that the continuation
+ * value (%ebx) is a 16-bit simple sequence counter (with the high 16
+ * bits ignored), and termination is always via CF=1 rather than
+ * %ebx=0.
+ *
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+get_underlying_e820:
+
+	/* If the requested region is in the cache, return it */
+	cmpw	%bx, underlying_e820_index
+	jne	2f
+	pushw	%di
+	pushw	%si
+	movw	$underlying_e820_cache, %si
+	cmpl	underlying_e820_cache_size, %ecx
+	jbe	1f
+	movl	underlying_e820_cache_size, %ecx
+1:	pushl	%ecx
+	rep movsb
+	popl	%ecx
+	popw	%si
+	popw	%di
+	incw	%bx
+	movl	%edx, %eax
+	clc
+	ret
+2:	
+	/* If the requested region is earlier than the cached region,
+	 * invalidate the cache.
+	 */
+	cmpw	%bx, underlying_e820_index
+	jbe	1f
+	movw	$0xffff, underlying_e820_index
+1:
+	/* If the cache is invalid, reset the underlying %ebx */
+	cmpw	$0xffff, underlying_e820_index
+	jne	1f
+	andl	$0, underlying_e820_ebx
+1:	
+	/* If the cache is valid but the continuation value is zero,
+	 * this means that the previous underlying call returned with
+	 * %ebx=0.  Return with CF=1 in this case.
+	 */
+	cmpw	$0xffff, underlying_e820_index
+	je	1f
+	cmpl	$0, underlying_e820_ebx
+	jne	1f
+	stc
+	ret
+1:	
+	/* Get the next region into the cache */
+	pushl	%eax
+	pushl	%ebx
+	pushl	%ecx
+	pushl	%edx
+	pushl	%esi	/* Some implementations corrupt %esi, so we	*/
+	pushl	%edi	/* preserve %esi, %edi and %ebp to be paranoid	*/
+	pushl	%ebp
+	pushw	%es
+	pushw	%ds
+	popw	%es
+	movw	$underlying_e820_cache, %di
+	cmpl	$E820MAXSIZE, %ecx
+	jbe	1f
+	movl	$E820MAXSIZE, %ecx
+1:	movl	underlying_e820_ebx, %ebx
+	stc
+	pushfw
+	lcall	*%cs:int15_vector
+	popw	%es
+	popl	%ebp
+	popl	%edi
+	popl	%esi
+	/* Check for error return from underlying e820 call */
+	jc	2f /* CF set: error */
+	cmpl	$SMAP, %eax
+	je	3f /* 'SMAP' missing: error */
+2:	/* An error occurred: return values returned by underlying e820 call */
+	stc	/* Force CF set if SMAP was missing */
+	addr32 leal 16(%esp), %esp /* avoid changing other flags */
+	ret
+3:	/* No error occurred */
+	movl	%ebx, underlying_e820_ebx
+	movl	%ecx, underlying_e820_cache_size
+	popl	%edx
+	popl	%ecx
+	popl	%ebx
+	popl	%eax
+	/* Mark cache as containing this result */
+	incw	underlying_e820_index
+
+	/* Loop until found */
+	jmp	get_underlying_e820
+	.size	get_underlying_e820, . - get_underlying_e820
+
+	.section ".data16", "aw", @progbits
+underlying_e820_index:
+	.word	0xffff /* Initialise to an invalid value */
+	.size underlying_e820_index, . - underlying_e820_index
+
+	.section ".bss16", "aw", @nobits
+underlying_e820_ebx:
+	.long	0
+	.size underlying_e820_ebx, . - underlying_e820_ebx
+
+	.section ".bss16", "aw", @nobits
+underlying_e820_cache:
+	.space	E820MAXSIZE
+	.size underlying_e820_cache, . - underlying_e820_cache
+
+	.section ".bss16", "aw", @nobits
+underlying_e820_cache_size:
+	.long	0
+	.size	underlying_e820_cache_size, . - underlying_e820_cache_size
+
+/****************************************************************************
+ * Get windowed e820 region, without empty region stripping
+ *
+ * Parameters:
+ *   As for INT 15,e820
+ * Returns:
+ *   As for INT 15,e820
+ *
+ * Wraps the underlying INT 15,e820 call so that each underlying
+ * region is returned N times, windowed to fit within N visible-memory
+ * windows.  Termination is always via CF=1.
+ *
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+get_windowed_e820:
+
+	/* Preserve registers */
+	pushl	%esi
+	pushw	%bp
+
+	/* Split %ebx into %si:%bx, store original %bx in %bp */
+	pushl	%ebx
+	popw	%bp
+	popw	%si
+
+	/* %si == 0 => start of memory_windows list */
+	testw	%si, %si
+	jne	1f
+	movw	$memory_windows, %si
+1:	
+	/* Get (cached) underlying e820 region to buffer */
+	call	get_underlying_e820
+	jc	99f /* Abort on error */
+
+	/* Preserve registers */
+	pushal
+	/* start => %edx:%eax, len => %ecx:%ebx */
+	movl	%es:0(%di), %eax
+	movl	%es:4(%di), %edx
+	movl	%es:8(%di), %ebx
+	movl	%es:12(%di), %ecx
+	/* Truncate region to current window */
+	call	window_region
+1:	/* Store modified values in e820 map entry */
+	movl	%eax, %es:0(%di)
+	movl	%edx, %es:4(%di)
+	movl	%ebx, %es:8(%di)
+	movl	%ecx, %es:12(%di)
+	/* Restore registers */
+	popal
+
+	/* Derive continuation value for next call */
+	addw	$16, %si
+	cmpw	$memory_windows_end, %si
+	jne	1f
+	/* End of memory windows: reset %si and allow %bx to continue */
+	xorw	%si, %si
+	jmp	2f
+1:	/* More memory windows to go: restore original %bx */
+	movw	%bp, %bx
+2:	/* Construct %ebx from %si:%bx */
+	pushw	%si
+	pushw	%bx
+	popl	%ebx
+
+98:	/* Clear CF */
+	clc
+99:	/* Restore registers and return */
+	popw	%bp
+	popl	%esi
+	ret
+	.size get_windowed_e820, . - get_windowed_e820
+
+/****************************************************************************
+ * Get windowed e820 region, with empty region stripping
+ *
+ * Parameters:
+ *   As for INT 15,e820
+ * Returns:
+ *   As for INT 15,e820
+ *
+ * Wraps the underlying INT 15,e820 call so that each underlying
+ * region is returned up to N times, windowed to fit within N
+ * visible-memory windows.  Empty windows are never returned.
+ * Termination is always via CF=1.
+ *
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+get_nonempty_e820:
+
+	/* Record entry parameters */
+	pushl	%eax
+	pushl	%ecx
+	pushl	%edx
+
+	/* Get next windowed region */
+	call	get_windowed_e820
+	jc	99f /* abort on error */
+
+	/* If region is non-empty, finish here */
+	cmpl	$0, %es:8(%di)
+	jne	98f
+	cmpl	$0, %es:12(%di)
+	jne	98f
+
+	/* Region was empty: restore entry parameters and go to next region */
+	popl	%edx
+	popl	%ecx
+	popl	%eax
+	jmp	get_nonempty_e820
+
+98:	/* Clear CF */
+	clc
+99:	/* Return values from underlying call */
+	addr32 leal 12(%esp), %esp /* avoid changing flags */
+	ret
+	.size get_nonempty_e820, . - get_nonempty_e820
+
+/****************************************************************************
+ * Get mangled e820 region, with empty region stripping
+ *
+ * Parameters:
+ *   As for INT 15,e820
+ * Returns:
+ *   As for INT 15,e820
+ *
+ * Wraps the underlying INT 15,e820 call so that underlying regions
+ * are windowed to the allowed memory regions.  Empty regions are
+ * stripped from the map.  Termination is always via %ebx=0.
+ *
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+get_mangled_e820:
+
+	/* Get a nonempty region */
+	call	get_nonempty_e820
+	jc	99f /* Abort on error */
+
+	/* Peek ahead to see if there are any further nonempty regions */
+	pushal
+	pushw	%es
+	movw	%sp, %bp
+	subw	%cx, %sp
+	movl	$0xe820, %eax
+	movl	$SMAP, %edx
+	pushw	%ss
+	popw	%es
+	movw	%sp, %di
+	call	get_nonempty_e820
+	movw	%bp, %sp
+	popw	%es
+	popal
+	jnc	99f /* There are further nonempty regions */
+
+	/* No futher nonempty regions: zero %ebx and clear CF */
+	xorl	%ebx, %ebx
+	
+99:	/* Return */
+	ret
+	.size get_mangled_e820, . - get_mangled_e820
+
+/****************************************************************************
+ * INT 15,e820 handler
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+int15_e820:
+	pushw	%ds
+	pushw	%cs:rm_ds
+	popw	%ds
+	call	get_mangled_e820
+	popw	%ds
+	call	patch_cf
+	iret
+	.size int15_e820, . - int15_e820
+	
+/****************************************************************************
+ * INT 15,e801 handler
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+int15_e801:
+	/* Call previous handler */
+	pushfw
+	lcall	*%cs:int15_vector
+	call	patch_cf
+	/* Edit result */
+	pushw	%ds
+	pushw	%cs:rm_ds
+	popw	%ds
+	call	patch_1m_16m
+	xchgw	%ax, %cx
+	xchgw	%bx, %dx
+	call	patch_1m_16m
+	xchgw	%ax, %cx
+	xchgw	%bx, %dx
+	popw	%ds
+	iret
+	.size int15_e801, . - int15_e801
+	
+/****************************************************************************
+ * INT 15,88 handler
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+int15_88:
+	/* Call previous handler */
+	pushfw
+	lcall	*%cs:int15_vector
+	call	patch_cf
+	/* Edit result */
+	pushw	%ds
+	pushw	%cs:rm_ds
+	popw	%ds
+	call	patch_1m
+	popw	%ds
+	iret
+	.size int15_88, . - int15_88
+		
+/****************************************************************************
+ * INT 15 handler
+ ****************************************************************************
+ */
+	.section ".text16", "ax", @progbits
+	.globl int15
+int15:
+	/* See if we want to intercept this call */
+	pushfw
+	cmpw	$0xe820, %ax
+	jne	1f
+	cmpl	$SMAP, %edx
+	jne	1f
+	popfw
+	jmp	int15_e820
+1:	cmpw	$0xe801, %ax
+	jne	2f
+	popfw
+	jmp	int15_e801
+2:	cmpb	$0x88, %ah
+	jne	3f
+	popfw
+	jmp	int15_88
+3:	popfw
+	ljmp	*%cs:int15_vector
+	.size int15, . - int15
+	
+	.section ".text16.data", "aw", @progbits
+	.globl int15_vector
+int15_vector:
+	.long 0
+	.size int15_vector, . - int15_vector

src/arch/x86/interface/pcbios/fakee820.c

@@ -0,0 +1,98 @@
+/* Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <realmode.h>
+#include <biosint.h>
+
+/** Assembly routine in inline asm */
+extern void int15_fakee820();
+
+/** Original INT 15 handler */
+static struct segoff __text16 ( real_int15_vector );
+#define real_int15_vector __use_text16 ( real_int15_vector )
+
+/** An INT 15,e820 memory map entry */
+struct e820_entry {
+	/** Start of region */
+	uint64_t start;
+	/** Length of region */
+	uint64_t len;
+	/** Type of region */
+	uint32_t type;
+} __attribute__ (( packed ));
+
+#define E820_TYPE_RAM		1 /**< Normal memory */
+#define E820_TYPE_RSVD		2 /**< Reserved and unavailable */
+#define E820_TYPE_ACPI		3 /**< ACPI reclaim memory */
+#define E820_TYPE_NVS		4 /**< ACPI NVS memory */
+
+/** Fake e820 map */
+static struct e820_entry __text16_array ( e820map, [] ) __used = {
+	{ 0x00000000ULL, ( 0x000a0000ULL - 0x00000000ULL ), E820_TYPE_RAM },
+	{ 0x00100000ULL, ( 0xcfb50000ULL - 0x00100000ULL ), E820_TYPE_RAM },
+	{ 0xcfb50000ULL, ( 0xcfb64000ULL - 0xcfb50000ULL ), E820_TYPE_RSVD },
+	{ 0xcfb64000ULL, ( 0xcfb66000ULL - 0xcfb64000ULL ), E820_TYPE_RSVD },
+	{ 0xcfb66000ULL, ( 0xcfb85c00ULL - 0xcfb66000ULL ), E820_TYPE_ACPI },
+	{ 0xcfb85c00ULL, ( 0xd0000000ULL - 0xcfb85c00ULL ), E820_TYPE_RSVD },
+	{ 0xe0000000ULL, ( 0xf0000000ULL - 0xe0000000ULL ), E820_TYPE_RSVD },
+	{ 0xfe000000ULL, (0x100000000ULL - 0xfe000000ULL ), E820_TYPE_RSVD },
+	{0x100000000ULL, (0x230000000ULL -0x100000000ULL ), E820_TYPE_RAM },
+};
+#define e820map __use_text16 ( e820map )
+
+void fake_e820 ( void ) {
+	__asm__ __volatile__ (
+		TEXT16_CODE ( "\nint15_fakee820:\n\t"
+			      "pushfw\n\t"
+			      "cmpl $0xe820, %%eax\n\t"
+			      "jne 99f\n\t"
+			      "cmpl $0x534d4150, %%edx\n\t"
+			      "jne 99f\n\t"
+			      "pushaw\n\t"
+			      "movw %%sp, %%bp\n\t"
+			      "andb $~0x01, 22(%%bp)\n\t" /* Clear return CF */
+			      "leaw e820map(%%bx), %%si\n\t"
+			      "cs rep movsb\n\t"
+			      "popaw\n\t"
+			      "movl %%edx, %%eax\n\t"
+			      "addl $20, %%ebx\n\t"
+			      "cmpl %0, %%ebx\n\t"
+			      "jne 1f\n\t"
+			      "xorl %%ebx,%%ebx\n\t"
+			      "\n1:\n\t"
+			      "popfw\n\t"
+			      "iret\n\t"
+			      "\n99:\n\t"
+			      "popfw\n\t"
+			      "ljmp *%%cs:real_int15_vector\n\t" )
+		: : "i" ( sizeof ( e820map ) ) );
+
+	hook_bios_interrupt ( 0x15, ( intptr_t ) int15_fakee820,
+			      &real_int15_vector );
+}
+
+void unfake_e820 ( void ) {
+	unhook_bios_interrupt ( 0x15, ( intptr_t ) int15_fakee820,
+				&real_int15_vector );
+}

src/arch/x86/interface/pcbios/hidemem.c

@@ -0,0 +1,234 @@
+/* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <assert.h>
+#include <realmode.h>
+#include <biosint.h>
+#include <basemem.h>
+#include <fakee820.h>
+#include <ipxe/init.h>
+#include <ipxe/io.h>
+#include <ipxe/hidemem.h>
+
+/** Set to true if you want to test a fake E820 map */
+#define FAKE_E820 0
+
+/** Alignment for hidden memory regions */
+#define ALIGN_HIDDEN 4096   /* 4kB page alignment should be enough */
+
+/**
+ * A hidden region of iPXE
+ *
+ * This represents a region that will be edited out of the system's
+ * memory map.
+ *
+ * This structure is accessed by assembly code, so must not be
+ * changed.
+ */
+struct hidden_region {
+	/** Physical start address */
+	uint64_t start;
+	/** Physical end address */
+	uint64_t end;
+};
+
+/** Hidden base memory */
+extern struct hidden_region __data16 ( hidemem_base );
+#define hidemem_base __use_data16 ( hidemem_base )
+
+/** Hidden umalloc memory */
+extern struct hidden_region __data16 ( hidemem_umalloc );
+#define hidemem_umalloc __use_data16 ( hidemem_umalloc )
+
+/** Hidden text memory */
+extern struct hidden_region __data16 ( hidemem_textdata );
+#define hidemem_textdata __use_data16 ( hidemem_textdata )
+
+/** Assembly routine in e820mangler.S */
+extern void int15();
+
+/** Vector for storing original INT 15 handler */
+extern struct segoff __text16 ( int15_vector );
+#define int15_vector __use_text16 ( int15_vector )
+
+/* The linker defines these symbols for us */
+extern char _textdata[];
+extern char _etextdata[];
+extern char _text16_memsz[];
+#define _text16_memsz ( ( size_t ) _text16_memsz )
+extern char _data16_memsz[];
+#define _data16_memsz ( ( size_t ) _data16_memsz )
+
+/**
+ * Hide region of memory from system memory map
+ *
+ * @v region		Hidden memory region
+ * @v start		Start of region
+ * @v end		End of region
+ */
+static void hide_region ( struct hidden_region *region,
+			  physaddr_t start, physaddr_t end ) {
+
+	/* Some operating systems get a nasty shock if a region of the
+	 * E820 map seems to start on a non-page boundary.  Make life
+	 * safer by rounding out our edited region.
+	 */
+	region->start = ( start & ~( ALIGN_HIDDEN - 1 ) );
+	region->end = ( ( end + ALIGN_HIDDEN - 1 ) & ~( ALIGN_HIDDEN - 1 ) );
+
+	DBG ( "Hiding region [%llx,%llx)\n", region->start, region->end );
+}
+
+/**
+ * Hide used base memory
+ *
+ */
+void hide_basemem ( void ) {
+	/* Hide from the top of free base memory to 640kB.  Don't use
+	 * hide_region(), because we don't want this rounded to the
+	 * nearest page boundary.
+	 */
+	hidemem_base.start = ( get_fbms() * 1024 );
+}
+
+/**
+ * Hide umalloc() region
+ *
+ */
+void hide_umalloc ( physaddr_t start, physaddr_t end ) {
+	assert ( end <= virt_to_phys ( _textdata ) );
+	hide_region ( &hidemem_umalloc, start, end );
+}
+
+/**
+ * Hide .text and .data
+ *
+ */
+void hide_textdata ( void ) {
+	hide_region ( &hidemem_textdata, virt_to_phys ( _textdata ),
+		      virt_to_phys ( _etextdata ) );
+}
+
+/**
+ * Hide Etherboot
+ *
+ * Installs an INT 15 handler to edit Etherboot out of the memory map
+ * returned by the BIOS.
+ */
+static void hide_etherboot ( void ) {
+	struct memory_map memmap;
+	unsigned int rm_ds_top;
+	unsigned int rm_cs_top;
+	unsigned int fbms;
+
+	/* Dump memory map before mangling */
+	DBG ( "Hiding iPXE from system memory map\n" );
+	get_memmap ( &memmap );
+
+	/* Hook in fake E820 map, if we're testing one */
+	if ( FAKE_E820 ) {
+		DBG ( "Hooking in fake E820 map\n" );
+		fake_e820();
+		get_memmap ( &memmap );
+	}
+
+	/* Initialise the hidden regions */
+	hide_basemem();
+	hide_umalloc ( virt_to_phys ( _textdata ), virt_to_phys ( _textdata ) );
+	hide_textdata();
+
+	/* Some really moronic BIOSes bring up the PXE stack via the
+	 * UNDI loader entry point and then don't bother to unload it
+	 * before overwriting the code and data segments.  If this
+	 * happens, we really don't want to leave INT 15 hooked,
+	 * because that will cause any loaded OS to die horribly as
+	 * soon as it attempts to fetch the system memory map.
+	 *
+	 * We use a heuristic to guess whether or not we are being
+	 * loaded sensibly.
+	 */
+	rm_cs_top = ( ( ( rm_cs << 4 ) + _text16_memsz + 1024 - 1 ) >> 10 );
+	rm_ds_top = ( ( ( rm_ds << 4 ) + _data16_memsz + 1024 - 1 ) >> 10 );
+	fbms = get_fbms();
+	if ( ( rm_cs_top < fbms ) && ( rm_ds_top < fbms ) ) {
+		DBG ( "Detected potentially unsafe UNDI load at CS=%04x "
+		      "DS=%04x FBMS=%dkB\n", rm_cs, rm_ds, fbms );
+		DBG ( "Disabling INT 15 memory hiding\n" );
+		return;
+	}
+
+	/* Hook INT 15 */
+	hook_bios_interrupt ( 0x15, ( intptr_t ) int15, &int15_vector );
+
+	/* Dump memory map after mangling */
+	DBG ( "Hidden iPXE from system memory map\n" );
+	get_memmap ( &memmap );
+}
+
+/**
+ * Unhide Etherboot
+ *
+ * Uninstalls the INT 15 handler installed by hide_etherboot(), if
+ * possible.
+ */
+static void unhide_etherboot ( int flags __unused ) {
+	struct memory_map memmap;
+	int rc;
+
+	/* If we have more than one hooked interrupt at this point, it
+	 * means that some other vector is still hooked, in which case
+	 * we can't safely unhook INT 15 because we need to keep our
+	 * memory protected.  (We expect there to be at least one
+	 * hooked interrupt, because INT 15 itself is still hooked).
+	 */
+	if ( hooked_bios_interrupts > 1 ) {
+		DBG ( "Cannot unhide: %d interrupt vectors still hooked\n",
+		      hooked_bios_interrupts );
+		return;
+	}
+
+	/* Try to unhook INT 15 */
+	if ( ( rc = unhook_bios_interrupt ( 0x15, ( intptr_t ) int15,
+					    &int15_vector ) ) != 0 ) {
+		DBG ( "Cannot unhook INT15: %s\n", strerror ( rc ) );
+		/* Leave it hooked; there's nothing else we can do,
+		 * and it should be intrinsically safe (though
+		 * wasteful of RAM).
+		 */
+	}
+
+	/* Unhook fake E820 map, if used */
+	if ( FAKE_E820 )
+		unfake_e820();
+
+	/* Dump memory map after unhiding */
+	DBG ( "Unhidden iPXE from system memory map\n" );
+	get_memmap ( &memmap );
+}
+
+/** Hide Etherboot startup function */
+struct startup_fn hide_etherboot_startup_fn __startup_fn ( STARTUP_EARLY ) = {
+	.startup = hide_etherboot,
+	.shutdown = unhide_etherboot,
+};

src/arch/x86/interface/pcbios/int13con.c

@@ -0,0 +1,284 @@
+/*
+ * Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <ipxe/console.h>
+#include <ipxe/init.h>
+#include <realmode.h>
+#include <int13.h>
+#include <config/console.h>
+
+/** @file
+ *
+ * INT13 disk log console
+ *
+ */
+
+/* Set default console usage if applicable */
+#if ! ( defined ( CONSOLE_INT13 ) && CONSOLE_EXPLICIT ( CONSOLE_INT13 ) )
+#undef CONSOLE_INT13
+#define CONSOLE_INT13 ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
+#endif
+
+/** Disk drive number */
+#define INT13CON_DRIVE 0x80
+
+/** Log partition type */
+#define INT13CON_PARTITION_TYPE 0xe0
+
+/** Maximum number of outstanding unwritten characters */
+#define INT13CON_MAX_UNWRITTEN 64
+
+/** Log partition header */
+struct int13con_header {
+	/** Magic signature */
+	char magic[10];
+} __attribute__ (( packed ));
+
+/** Log partition magic signature */
+#define INT13CON_MAGIC "iPXE LOG\n\n"
+
+/** Sector buffer */
+static uint8_t __bss16_array ( int13con_buffer, [INT13_BLKSIZE] );
+#define int13con_buffer __use_data16 ( int13con_buffer )
+
+/** Disk address packet */
+static struct int13_disk_address __bss16 ( int13con_address );
+#define int13con_address __use_data16 ( int13con_address )
+
+/** Current LBA */
+static uint64_t int13con_lba;
+
+/** Maximum LBA */
+static uint64_t int13con_max_lba;
+
+/** Current offset within sector */
+static size_t int13con_offset;
+
+/** Number of unwritten characters */
+static size_t int13con_unwritten;
+
+struct console_driver int13con __console_driver;
+
+/**
+ * Read/write disk sector
+ *
+ * @v op		Operation
+ * @v lba		Logical block address
+ * @ret rc		Return status code
+ */
+static int int13con_rw ( unsigned int op, uint64_t lba ) {
+	uint8_t error;
+
+	/* Construct disk address packet */
+	int13con_address.bufsize = sizeof ( int13con_address );
+	int13con_address.count = 1;
+	int13con_address.buffer.segment = rm_ds;
+	int13con_address.buffer.offset = __from_data16 ( int13con_buffer );
+	int13con_address.lba = lba;
+
+	/* Issue INT13 */
+	__asm__ ( REAL_CODE ( "int $0x13\n\t" )
+		  : "=a" ( error )
+		  : "0" ( op << 8 ), "d" ( INT13CON_DRIVE ),
+		    "S" ( __from_data16 ( &int13con_address ) ) );
+	if ( error ) {
+		DBG ( "INT13CON operation %04x failed: %02x\n",
+		      op, error );
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * Write character to console
+ *
+ * @v character		Character
+ */
+static void int13con_putchar ( int character ) {
+	static int busy;
+	int rc;
+
+	/* Ignore if we are already mid-logging */
+	if ( busy )
+		return;
+	busy = 1;
+
+	/* Write character to buffer */
+	int13con_buffer[int13con_offset++] = character;
+	int13con_unwritten++;
+
+	/* Write sector to disk, if applicable */
+	if ( ( int13con_offset == INT13_BLKSIZE ) ||
+	     ( int13con_unwritten == INT13CON_MAX_UNWRITTEN ) ||
+	     ( character == '\n' ) ) {
+
+		/* Write sector to disk */
+		if ( ( rc = int13con_rw ( INT13_EXTENDED_WRITE,
+					  int13con_lba ) ) != 0 ) {
+			DBG ( "INT13CON could not write log\n" );
+			/* Ignore and continue; there's nothing we can do */
+		}
+
+		/* Reset count of unwritten characters */
+		int13con_unwritten = 0;
+	}
+
+	/* Move to next sector, if applicable */
+	if ( int13con_offset == INT13_BLKSIZE ) {
+
+		/* Disable console if we have run out of space */
+		if ( int13con_lba >= int13con_max_lba )
+			int13con.disabled = 1;
+
+		/* Clear log buffer */
+		memset ( int13con_buffer, 0, sizeof ( int13con_buffer ) );
+		int13con_offset = 0;
+
+		/* Move to next sector */
+		int13con_lba++;
+	}
+
+	/* Clear busy flag */
+	busy = 0;
+}
+
+/**
+ * Find log partition
+ *
+ * @ret rc		Return status code
+ */
+static int int13con_find ( void ) {
+	struct master_boot_record *mbr =
+		( ( struct master_boot_record * ) int13con_buffer );
+	struct int13con_header *hdr =
+		( ( struct int13con_header * ) int13con_buffer );
+	struct partition_table_entry part[4];
+	unsigned int i;
+	int rc;
+
+	/* Read MBR */
+	if ( ( rc = int13con_rw ( INT13_EXTENDED_READ, 0 ) ) != 0 ) {
+		DBG ( "INT13CON could not read MBR: %s\n", strerror ( rc ) );
+		return rc;
+	}
+
+	/* Check MBR magic */
+	if ( mbr->magic != INT13_MBR_MAGIC ) {
+		DBG ( "INT13CON incorrect MBR magic\n" );
+		DBG2_HDA ( 0, mbr, sizeof ( *mbr ) );
+		return -EINVAL;
+	}
+
+	/* Look for magic partition */
+	memcpy ( part, mbr->partitions, sizeof ( part ) );
+	for ( i = 0 ; i < ( sizeof ( part ) / sizeof ( part[0] ) ) ; i++ ) {
+
+		/* Skip partitions of the wrong type */
+		if ( part[i].type != INT13CON_PARTITION_TYPE )
+			continue;
+
+		/* Read partition header */
+		if ( ( rc = int13con_rw ( INT13_EXTENDED_READ,
+					  part[i].start ) ) != 0 ) {
+			DBG ( "INT13CON partition %d could not read header: "
+			      "%s\n", ( i + 1 ), strerror ( rc ) );
+			continue;
+		}
+
+		/* Check partition header */
+		if ( memcmp ( hdr->magic, INT13CON_MAGIC,
+			      sizeof ( hdr->magic ) ) != 0 ) {
+			DBG ( "INT13CON partition %d bad magic\n", ( i + 1 ) );
+			DBG2_HDA ( 0, hdr, sizeof ( *hdr ) );
+			continue;
+		}
+
+		/* Found log partition */
+		DBG ( "INT13CON partition %d at [%08x,%08x)\n", ( i + 1 ),
+		      part[i].start, ( part[i].start + part[i].length ) );
+		int13con_lba = part[i].start;
+		int13con_max_lba = ( part[i].start + part[i].length - 1 );
+
+		/* Initialise log buffer */
+		memset ( &int13con_buffer[ sizeof ( *hdr ) ], 0,
+			 ( sizeof ( int13con_buffer ) - sizeof ( *hdr ) ) );
+		int13con_offset = sizeof ( hdr->magic );
+
+		return 0;
+	}
+
+	DBG ( "INT13CON found no log partition\n" );
+	return -ENOENT;
+}
+
+/**
+ * Initialise INT13 console
+ *
+ */
+static void int13con_init ( void ) {
+	uint8_t error;
+	uint16_t check;
+	unsigned int discard_c;
+	unsigned int discard_d;
+	int rc;
+
+	/* Check for INT13 extensions */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x13\n\t"
+					   "setc %%al\n\t" )
+			       : "=a" ( error ), "=b" ( check ),
+				 "=c" ( discard_c ), "=d" ( discard_d )
+			       : "0" ( INT13_EXTENSION_CHECK << 8 ),
+				 "1" ( 0x55aa ), "3" ( INT13CON_DRIVE ) );
+	if ( error || ( check != 0xaa55 ) ) {
+		DBG ( "INT13CON missing extensions (%02x,%04x)\n",
+		      error, check );
+		return;
+	}
+
+	/* Locate log partition */
+	if ( ( rc = int13con_find() ) != 0)
+		return;
+
+	/* Enable console */
+	int13con.disabled = 0;
+}
+
+/**
+ * INT13 console initialisation function
+ */
+struct init_fn int13con_init_fn __init_fn ( INIT_CONSOLE ) = {
+	.initialise = int13con_init,
+};
+
+/** INT13 console driver */
+struct console_driver int13con __console_driver = {
+	.putchar = int13con_putchar,
+	.disabled = CONSOLE_DISABLED,
+	.usage = CONSOLE_INT13,
+};

src/arch/x86/interface/pcbios/memmap.c

@@ -0,0 +1,343 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <errno.h>
+#include <realmode.h>
+#include <bios.h>
+#include <memsizes.h>
+#include <ipxe/io.h>
+
+/**
+ * @file
+ *
+ * Memory mapping
+ *
+ */
+
+/** Magic value for INT 15,e820 calls */
+#define SMAP ( 0x534d4150 )
+
+/** An INT 15,e820 memory map entry */
+struct e820_entry {
+	/** Start of region */
+	uint64_t start;
+	/** Length of region */
+	uint64_t len;
+	/** Type of region */
+	uint32_t type;
+	/** Extended attributes (optional) */
+	uint32_t attrs;
+} __attribute__ (( packed ));
+
+#define E820_TYPE_RAM		1 /**< Normal memory */
+#define E820_TYPE_RESERVED	2 /**< Reserved and unavailable */
+#define E820_TYPE_ACPI		3 /**< ACPI reclaim memory */
+#define E820_TYPE_NVS		4 /**< ACPI NVS memory */
+
+#define E820_ATTR_ENABLED	0x00000001UL
+#define E820_ATTR_NONVOLATILE	0x00000002UL
+#define E820_ATTR_UNKNOWN	0xfffffffcUL
+
+#define E820_MIN_SIZE		20
+
+/** Buffer for INT 15,e820 calls */
+static struct e820_entry __bss16 ( e820buf );
+#define e820buf __use_data16 ( e820buf )
+
+/** We are running during POST; inhibit INT 15,e820 and INT 15,e801 */
+uint8_t __bss16 ( memmap_post );
+#define memmap_post __use_data16 ( memmap_post )
+
+/**
+ * Get size of extended memory via INT 15,e801
+ *
+ * @ret extmem		Extended memory size, in kB, or 0
+ */
+static unsigned int extmemsize_e801 ( void ) {
+	uint16_t extmem_1m_to_16m_k, extmem_16m_plus_64k;
+	uint16_t confmem_1m_to_16m_k, confmem_16m_plus_64k;
+	unsigned int flags;
+	unsigned int extmem;
+
+	/* Inhibit INT 15,e801 during POST */
+	if ( memmap_post ) {
+		DBG ( "INT 15,e801 not available during POST\n" );
+		return 0;
+	}
+
+	__asm__ __volatile__ ( REAL_CODE ( "stc\n\t"
+					   "int $0x15\n\t"
+					   "pushfw\n\t"
+					   "popw %w0\n\t" )
+			       : "=R" ( flags ),
+				 "=a" ( extmem_1m_to_16m_k ),
+				 "=b" ( extmem_16m_plus_64k ),
+				 "=c" ( confmem_1m_to_16m_k ),
+				 "=d" ( confmem_16m_plus_64k )
+			       : "a" ( 0xe801 ) );
+
+	if ( flags & CF ) {
+		DBG ( "INT 15,e801 failed with CF set\n" );
+		return 0;
+	}
+
+	if ( ! ( extmem_1m_to_16m_k | extmem_16m_plus_64k ) ) {
+		DBG ( "INT 15,e801 extmem=0, using confmem\n" );
+		extmem_1m_to_16m_k = confmem_1m_to_16m_k;
+		extmem_16m_plus_64k = confmem_16m_plus_64k;
+	}
+
+	extmem = ( extmem_1m_to_16m_k + ( extmem_16m_plus_64k * 64 ) );
+	DBG ( "INT 15,e801 extended memory size %d+64*%d=%d kB "
+	      "[100000,%llx)\n", extmem_1m_to_16m_k, extmem_16m_plus_64k,
+	      extmem, ( 0x100000 + ( ( ( uint64_t ) extmem ) * 1024 ) ) );
+
+	/* Sanity check.  Some BIOSes report the entire 4GB address
+	 * space as available, which cannot be correct (since that
+	 * would leave no address space available for 32-bit PCI
+	 * BARs).
+	 */
+	if ( extmem == ( 0x400000 - 0x400 ) ) {
+		DBG ( "INT 15,e801 reported whole 4GB; assuming insane\n" );
+		return 0;
+	}
+
+	return extmem;
+}
+
+/**
+ * Get size of extended memory via INT 15,88
+ *
+ * @ret extmem		Extended memory size, in kB
+ */
+static unsigned int extmemsize_88 ( void ) {
+	uint16_t extmem;
+
+	/* Ignore CF; it is not reliable for this call */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x15" )
+			       : "=a" ( extmem ) : "a" ( 0x8800 ) );
+
+	DBG ( "INT 15,88 extended memory size %d kB [100000, %x)\n",
+	      extmem, ( 0x100000 + ( extmem * 1024 ) ) );
+	return extmem;
+}
+
+/**
+ * Get size of extended memory
+ *
+ * @ret extmem		Extended memory size, in kB
+ *
+ * Note that this is only an approximation; for an accurate picture,
+ * use the E820 memory map obtained via get_memmap();
+ */
+unsigned int extmemsize ( void ) {
+	unsigned int extmem_e801;
+	unsigned int extmem_88;
+
+	/* Try INT 15,e801 first, then fall back to INT 15,88 */
+	extmem_88 = extmemsize_88();
+	extmem_e801 = extmemsize_e801();
+	return ( extmem_e801 ? extmem_e801 : extmem_88 );
+}
+
+/**
+ * Get e820 memory map
+ *
+ * @v memmap		Memory map to fill in
+ * @ret rc		Return status code
+ */
+static int meme820 ( struct memory_map *memmap ) {
+	struct memory_region *region = memmap->regions;
+	struct memory_region *prev_region = NULL;
+	uint32_t next = 0;
+	uint32_t smap;
+	size_t size;
+	unsigned int flags;
+	unsigned int discard_D;
+
+	/* Inhibit INT 15,e820 during POST */
+	if ( memmap_post ) {
+		DBG ( "INT 15,e820 not available during POST\n" );
+		return -ENOTTY;
+	}
+
+	/* Clear the E820 buffer.  Do this once before starting,
+	 * rather than on each call; some BIOSes rely on the contents
+	 * being preserved between calls.
+	 */
+	memset ( &e820buf, 0, sizeof ( e820buf ) );
+
+	do {
+		/* Some BIOSes corrupt %esi for fun. Guard against
+		 * this by telling gcc that all non-output registers
+		 * may be corrupted.
+		 */
+		__asm__ __volatile__ ( REAL_CODE ( "pushl %%ebp\n\t"
+						   "stc\n\t"
+						   "int $0x15\n\t"
+						   "pushfw\n\t"
+						   "popw %%dx\n\t"
+						   "popl %%ebp\n\t" )
+				       : "=a" ( smap ), "=b" ( next ),
+					 "=c" ( size ), "=d" ( flags ),
+					 "=D" ( discard_D )
+				       : "a" ( 0xe820 ), "b" ( next ),
+					 "D" ( __from_data16 ( &e820buf ) ),
+					 "c" ( sizeof ( e820buf ) ),
+					 "d" ( SMAP )
+				       : "esi", "memory" );
+
+		if ( smap != SMAP ) {
+			DBG ( "INT 15,e820 failed SMAP signature check\n" );
+			return -ENOTSUP;
+		}
+
+		if ( size < E820_MIN_SIZE ) {
+			DBG ( "INT 15,e820 returned only %zd bytes\n", size );
+			return -EINVAL;
+		}
+
+		if ( flags & CF ) {
+			DBG ( "INT 15,e820 terminated on CF set\n" );
+			break;
+		}
+
+		/* If first region is not RAM, assume map is invalid */
+		if ( ( memmap->count == 0 ) &&
+		     ( e820buf.type != E820_TYPE_RAM ) ) {
+		       DBG ( "INT 15,e820 failed, first entry not RAM\n" );
+		       return -EINVAL;
+		}
+
+		DBG ( "INT 15,e820 region [%llx,%llx) type %d",
+		      e820buf.start, ( e820buf.start + e820buf.len ),
+		      ( int ) e820buf.type );
+		if ( size > offsetof ( typeof ( e820buf ), attrs ) ) {
+			DBG ( " (%s", ( ( e820buf.attrs & E820_ATTR_ENABLED )
+					? "enabled" : "disabled" ) );
+			if ( e820buf.attrs & E820_ATTR_NONVOLATILE )
+				DBG ( ", non-volatile" );
+			if ( e820buf.attrs & E820_ATTR_UNKNOWN )
+				DBG ( ", other [%08x]", e820buf.attrs );
+			DBG ( ")" );
+		}
+		DBG ( "\n" );
+
+		/* Discard non-RAM regions */
+		if ( e820buf.type != E820_TYPE_RAM )
+			continue;
+
+		/* Check extended attributes, if present */
+		if ( size > offsetof ( typeof ( e820buf ), attrs ) ) {
+			if ( ! ( e820buf.attrs & E820_ATTR_ENABLED ) )
+				continue;
+			if ( e820buf.attrs & E820_ATTR_NONVOLATILE )
+				continue;
+		}
+
+		region->start = e820buf.start;
+		region->end = e820buf.start + e820buf.len;
+
+		/* Check for adjacent regions and merge them */
+		if ( prev_region && ( region->start == prev_region->end ) ) {
+			prev_region->end = region->end;
+		} else {
+			prev_region = region;
+			region++;
+			memmap->count++;
+		}
+
+		if ( memmap->count >= ( sizeof ( memmap->regions ) /
+					sizeof ( memmap->regions[0] ) ) ) {
+			DBG ( "INT 15,e820 too many regions returned\n" );
+			/* Not a fatal error; what we've got so far at
+			 * least represents valid regions of memory,
+			 * even if we couldn't get them all.
+			 */
+			break;
+		}
+	} while ( next != 0 );
+
+	/* Sanity checks.  Some BIOSes report complete garbage via INT
+	 * 15,e820 (especially at POST time), despite passing the
+	 * signature checks.  We currently check for a base memory
+	 * region (starting at 0) and at least one high memory region
+	 * (starting at 0x100000).
+	 */
+	if ( memmap->count < 2 ) {
+		DBG ( "INT 15,e820 returned only %d regions; assuming "
+		      "insane\n", memmap->count );
+		return -EINVAL;
+	}
+	if ( memmap->regions[0].start != 0 ) {
+		DBG ( "INT 15,e820 region 0 starts at %llx (expected 0); "
+		      "assuming insane\n", memmap->regions[0].start );
+		return -EINVAL;
+	}
+	if ( memmap->regions[1].start != 0x100000 ) {
+		DBG ( "INT 15,e820 region 1 starts at %llx (expected 100000); "
+		      "assuming insane\n", memmap->regions[0].start );
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * Get memory map
+ *
+ * @v memmap		Memory map to fill in
+ */
+void x86_get_memmap ( struct memory_map *memmap ) {
+	unsigned int basemem, extmem;
+	int rc;
+
+	DBG ( "Fetching system memory map\n" );
+
+	/* Clear memory map */
+	memset ( memmap, 0, sizeof ( *memmap ) );
+
+	/* Get base and extended memory sizes */
+	basemem = basememsize();
+	DBG ( "FBMS base memory size %d kB [0,%x)\n",
+	      basemem, ( basemem * 1024 ) );
+	extmem = extmemsize();
+	
+	/* Try INT 15,e820 first */
+	if ( ( rc = meme820 ( memmap ) ) == 0 ) {
+		DBG ( "Obtained system memory map via INT 15,e820\n" );
+		return;
+	}
+
+	/* Fall back to constructing a map from basemem and extmem sizes */
+	DBG ( "INT 15,e820 failed; constructing map\n" );
+	memmap->regions[0].end = ( basemem * 1024 );
+	memmap->regions[1].start = 0x100000;
+	memmap->regions[1].end = 0x100000 + ( extmem * 1024 );
+	memmap->count = 2;
+}
+
+PROVIDE_IOAPI ( x86, get_memmap, x86_get_memmap );

src/arch/x86/interface/pcbios/memtop_umalloc.c

@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/**
+ * @file
+ *
+ * External memory allocation
+ *
+ */
+
+#include <limits.h>
+#include <errno.h>
+#include <ipxe/uaccess.h>
+#include <ipxe/hidemem.h>
+#include <ipxe/io.h>
+#include <ipxe/memblock.h>
+#include <ipxe/umalloc.h>
+
+/** Alignment of external allocated memory */
+#define EM_ALIGN ( 4 * 1024 )
+
+/** Equivalent of NOWHERE for user pointers */
+#define UNOWHERE ( ~UNULL )
+
+/** An external memory block */
+struct external_memory {
+	/** Size of this memory block (excluding this header) */
+	size_t size;
+	/** Block is currently in use */
+	int used;
+};
+
+/** Top of heap */
+static userptr_t top = UNULL;
+
+/** Bottom of heap (current lowest allocated block) */
+static userptr_t bottom = UNULL;
+
+/** Remaining space on heap */
+static size_t heap_size;
+
+/**
+ * Initialise external heap
+ *
+ */
+static void init_eheap ( void ) {
+	userptr_t base;
+
+	heap_size = largest_memblock ( &base );
+	bottom = top = userptr_add ( base, heap_size );
+	DBG ( "External heap grows downwards from %lx (size %zx)\n",
+	      user_to_phys ( top, 0 ), heap_size );
+}
+
+/**
+ * Collect free blocks
+ *
+ */
+static void ecollect_free ( void ) {
+	struct external_memory extmem;
+	size_t len;
+
+	/* Walk the free list and collect empty blocks */
+	while ( bottom != top ) {
+		copy_from_user ( &extmem, bottom, -sizeof ( extmem ),
+				 sizeof ( extmem ) );
+		if ( extmem.used )
+			break;
+		DBG ( "EXTMEM freeing [%lx,%lx)\n", user_to_phys ( bottom, 0 ),
+		      user_to_phys ( bottom, extmem.size ) );
+		len = ( extmem.size + sizeof ( extmem ) );
+		bottom = userptr_add ( bottom, len );
+		heap_size += len;
+	}
+}
+
+/**
+ * Reallocate external memory
+ *
+ * @v old_ptr		Memory previously allocated by umalloc(), or UNULL
+ * @v new_size		Requested size
+ * @ret new_ptr		Allocated memory, or UNULL
+ *
+ * Calling realloc() with a new size of zero is a valid way to free a
+ * memory block.
+ */
+static userptr_t memtop_urealloc ( userptr_t ptr, size_t new_size ) {
+	struct external_memory extmem;
+	userptr_t new = ptr;
+	size_t align;
+
+	/* (Re)initialise external memory allocator if necessary */
+	if ( bottom == top )
+		init_eheap();
+
+	/* Get block properties into extmem */
+	if ( ptr && ( ptr != UNOWHERE ) ) {
+		/* Determine old size */
+		copy_from_user ( &extmem, ptr, -sizeof ( extmem ),
+				 sizeof ( extmem ) );
+	} else {
+		/* Create a zero-length block */
+		if ( heap_size < sizeof ( extmem ) ) {
+			DBG ( "EXTMEM out of space\n" );
+			return UNULL;
+		}
+		ptr = bottom = userptr_add ( bottom, -sizeof ( extmem ) );
+		heap_size -= sizeof ( extmem );
+		DBG ( "EXTMEM allocating [%lx,%lx)\n",
+		      user_to_phys ( ptr, 0 ), user_to_phys ( ptr, 0 ) );
+		extmem.size = 0;
+	}
+	extmem.used = ( new_size > 0 );
+
+	/* Expand/shrink block if possible */
+	if ( ptr == bottom ) {
+		/* Update block */
+		if ( new_size > ( heap_size - extmem.size ) ) {
+			DBG ( "EXTMEM out of space\n" );
+			return UNULL;
+		}
+		new = userptr_add ( ptr, - ( new_size - extmem.size ) );
+		align = ( user_to_phys ( new, 0 ) & ( EM_ALIGN - 1 ) );
+		new_size += align;
+		new = userptr_add ( new, -align );
+		DBG ( "EXTMEM expanding [%lx,%lx) to [%lx,%lx)\n",
+		      user_to_phys ( ptr, 0 ),
+		      user_to_phys ( ptr, extmem.size ),
+		      user_to_phys ( new, 0 ),
+		      user_to_phys ( new, new_size ));
+		memmove_user ( new, 0, ptr, 0, ( ( extmem.size < new_size ) ?
+						 extmem.size : new_size ) );
+		bottom = new;
+		heap_size -= ( new_size - extmem.size );
+		extmem.size = new_size;
+	} else {
+		/* Cannot expand; can only pretend to shrink */
+		if ( new_size > extmem.size ) {
+			/* Refuse to expand */
+			DBG ( "EXTMEM cannot expand [%lx,%lx)\n",
+			      user_to_phys ( ptr, 0 ),
+			      user_to_phys ( ptr, extmem.size ) );
+			return UNULL;
+		}
+	}
+
+	/* Write back block properties */
+	copy_to_user ( new, -sizeof ( extmem ), &extmem,
+		       sizeof ( extmem ) );
+
+	/* Collect any free blocks and update hidden memory region */
+	ecollect_free();
+	hide_umalloc ( user_to_phys ( bottom, ( ( bottom == top ) ?
+						0 : -sizeof ( extmem ) ) ),
+		       user_to_phys ( top, 0 ) );
+
+	return ( new_size ? new : UNOWHERE );
+}
+
+PROVIDE_UMALLOC ( memtop, urealloc, memtop_urealloc );

src/arch/x86/interface/pcbios/pcibios.c

@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <ipxe/pci.h>
+#include <realmode.h>
+
+/** @file
+ *
+ * PCI configuration space access via PCI BIOS
+ *
+ */
+
+/**
+ * Determine number of PCI buses within system
+ *
+ * @ret num_bus		Number of buses
+ */
+static int pcibios_num_bus ( void ) {
+	int discard_a, discard_D;
+	uint8_t max_bus;
+
+	/* We issue this call using flat real mode, to work around a
+	 * bug in some HP BIOSes.
+	 */
+	__asm__ __volatile__ ( REAL_CODE ( "call flatten_real_mode\n\t"
+					   "stc\n\t"
+					   "int $0x1a\n\t"
+					   "jnc 1f\n\t"
+					   "xorw %%cx, %%cx\n\t"
+					   "\n1:\n\t" )
+			       : "=c" ( max_bus ), "=a" ( discard_a ),
+				 "=D" ( discard_D )
+			       : "a" ( PCIBIOS_INSTALLATION_CHECK >> 16 ),
+				 "D" ( 0 )
+			       : "ebx", "edx" );
+
+	return ( max_bus + 1 );
+}
+
+/**
+ * Read configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v command	PCI BIOS command
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+int pcibios_read ( struct pci_device *pci, uint32_t command, uint32_t *value ){
+	int discard_b, discard_D;
+	int status;
+
+	__asm__ __volatile__ ( REAL_CODE ( "stc\n\t"
+					   "int $0x1a\n\t"
+					   "jnc 1f\n\t"
+					   "xorl %%eax, %%eax\n\t"
+					   "decl %%eax\n\t"
+					   "movl %%eax, %%ecx\n\t"
+					   "\n1:\n\t" )
+			       : "=a" ( status ), "=b" ( discard_b ),
+				 "=c" ( *value ), "=D" ( discard_D )
+			       : "a" ( command >> 16 ), "D" ( command ),
+				 "b" ( pci->busdevfn )
+			       : "edx" );
+
+	return ( ( status >> 8 ) & 0xff );
+}
+
+/**
+ * Write configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v command	PCI BIOS command
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+int pcibios_write ( struct pci_device *pci, uint32_t command, uint32_t value ){
+	int discard_b, discard_c, discard_D;
+	int status;
+
+	__asm__ __volatile__ ( REAL_CODE ( "stc\n\t"
+					   "int $0x1a\n\t"
+					   "jnc 1f\n\t"
+					   "movb $0xff, %%ah\n\t"
+					   "\n1:\n\t" )
+			       : "=a" ( status ), "=b" ( discard_b ),
+				 "=c" ( discard_c ), "=D" ( discard_D )
+			       : "a" ( command >> 16 ),	"D" ( command ),
+			         "b" ( pci->busdevfn ), "c" ( value )
+			       : "edx" );
+	
+	return ( ( status >> 8 ) & 0xff );
+}
+
+PROVIDE_PCIAPI ( pcbios, pci_num_bus, pcibios_num_bus );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_byte );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_word );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_dword );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_byte );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_word );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_dword );

src/arch/x86/interface/pcbios/pnpbios.c

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <realmode.h>
+#include <pnpbios.h>
+
+/** @file
+ *
+ * PnP BIOS
+ *
+ */
+
+/** PnP BIOS structure */
+struct pnp_bios {
+	/** Signature
+	 *
+	 * Must be equal to @c PNP_BIOS_SIGNATURE
+	 */
+	uint32_t signature;
+	/** Version as BCD (e.g. 1.0 is 0x10) */
+	uint8_t version;
+	/** Length of this structure */
+	uint8_t length;
+	/** System capabilities */
+	uint16_t control;
+	/** Checksum */
+	uint8_t checksum;
+} __attribute__ (( packed ));
+
+/** Signature for a PnP BIOS structure */
+#define PNP_BIOS_SIGNATURE \
+	( ( '$' << 0 ) + ( 'P' << 8 ) + ( 'n' << 16 ) + ( 'P' << 24 ) )
+
+/**
+ * Test address for PnP BIOS structure
+ *
+ * @v offset		Offset within BIOS segment to test
+ * @ret rc		Return status code
+ */
+static int is_pnp_bios ( unsigned int offset ) {
+	union {
+		struct pnp_bios pnp_bios;
+		uint8_t bytes[256]; /* 256 is maximum length possible */
+	} u;
+	size_t len;
+	unsigned int i;
+	uint8_t sum = 0;
+
+	/* Read start of header and verify signature */
+	copy_from_real ( &u.pnp_bios, BIOS_SEG, offset, sizeof ( u.pnp_bios ));
+	if ( u.pnp_bios.signature != PNP_BIOS_SIGNATURE )
+		return -EINVAL;
+
+	/* Read whole header and verify checksum */
+	len = u.pnp_bios.length;
+	copy_from_real ( &u.bytes, BIOS_SEG, offset, len );
+	for ( i = 0 ; i < len ; i++ ) {
+		sum += u.bytes[i];
+	}
+	if ( sum != 0 )
+		return -EINVAL;
+
+	DBG ( "Found PnP BIOS at %04x:%04x\n", BIOS_SEG, offset );
+
+	return 0;
+}
+
+/**
+ * Locate Plug-and-Play BIOS
+ *
+ * @ret pnp_offset	Offset of PnP BIOS structure within BIOS segment
+ *
+ * The PnP BIOS structure will be at BIOS_SEG:pnp_offset.  If no PnP
+ * BIOS is found, -1 is returned.
+ */
+int find_pnp_bios ( void ) {
+	static int pnp_offset = 0;
+
+	if ( pnp_offset )
+		return pnp_offset;
+
+	for ( pnp_offset = 0 ; pnp_offset < 0x10000 ; pnp_offset += 0x10 ) {
+		if ( is_pnp_bios ( pnp_offset ) == 0 )
+			return pnp_offset;
+	}
+
+	pnp_offset = -1;
+	return pnp_offset;
+}

src/arch/x86/interface/pcbios/rtc_entropy.c

@@ -0,0 +1,199 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * RTC-based entropy source
+ *
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <biosint.h>
+#include <pic8259.h>
+#include <rtc.h>
+#include <ipxe/entropy.h>
+
+/** RTC interrupt handler */
+extern void rtc_isr ( void );
+
+/** Previous RTC interrupt handler */
+static struct segoff rtc_old_handler;
+
+/**
+ * Hook RTC interrupt handler
+ *
+ */
+static void rtc_hook_isr ( void ) {
+
+	/* RTC interrupt handler */
+	__asm__ __volatile__ (
+		TEXT16_CODE ( "\nrtc_isr:\n\t"
+			      /* Preserve registers */
+			      "pushw %%ax\n\t"
+			      /* Set "interrupt triggered" flag */
+			      "movb $0x01, %%cs:rtc_flag\n\t"
+			      /* Read RTC status register C to
+			       * acknowledge interrupt
+			       */
+			      "movb %2, %%al\n\t"
+			      "outb %%al, %0\n\t"
+			      "inb %1\n\t"
+			      /* Send EOI */
+			      "movb $0x20, %%al\n\t"
+			      "outb %%al, $0xa0\n\t"
+			      "outb %%al, $0x20\n\t"
+			      /* Restore registers and return */
+			      "popw %%ax\n\t"
+			      "iret\n\t"
+			      "\nrtc_flag:\n\t"
+			      ".byte 0\n\t" )
+		:
+		: "i" ( CMOS_ADDRESS ), "i" ( CMOS_DATA ),
+		  "i" ( RTC_STATUS_C ) );
+
+	hook_bios_interrupt ( RTC_INT, ( intptr_t ) rtc_isr, &rtc_old_handler );
+}
+
+/**
+ * Unhook RTC interrupt handler
+ *
+ */
+static void rtc_unhook_isr ( void ) {
+	int rc;
+
+	rc = unhook_bios_interrupt ( RTC_INT, ( intptr_t ) rtc_isr,
+				     &rtc_old_handler );
+	assert ( rc == 0 ); /* Should always be able to unhook */
+}
+
+/**
+ * Enable RTC interrupts
+ *
+ */
+static void rtc_enable_int ( void ) {
+	uint8_t status_b;
+
+	/* Set Periodic Interrupt Enable bit in status register B */
+	outb ( ( RTC_STATUS_B | CMOS_DISABLE_NMI ), CMOS_ADDRESS );
+	status_b = inb ( CMOS_DATA );
+	outb ( ( RTC_STATUS_B | CMOS_DISABLE_NMI ), CMOS_ADDRESS );
+	outb ( ( status_b | RTC_STATUS_B_PIE ), CMOS_DATA );
+
+	/* Re-enable NMI and reset to default address */
+	outb ( CMOS_DEFAULT_ADDRESS, CMOS_ADDRESS );
+	inb ( CMOS_DATA ); /* Discard; may be needed on some platforms */
+}
+
+/**
+ * Disable RTC interrupts
+ *
+ */
+static void rtc_disable_int ( void ) {
+	uint8_t status_b;
+
+	/* Clear Periodic Interrupt Enable bit in status register B */
+	outb ( ( RTC_STATUS_B | CMOS_DISABLE_NMI ), CMOS_ADDRESS );
+	status_b = inb ( CMOS_DATA );
+	outb ( ( RTC_STATUS_B | CMOS_DISABLE_NMI ), CMOS_ADDRESS );
+	outb ( ( status_b & ~RTC_STATUS_B_PIE ), CMOS_DATA );
+
+	/* Re-enable NMI and reset to default address */
+	outb ( CMOS_DEFAULT_ADDRESS, CMOS_ADDRESS );
+	inb ( CMOS_DATA ); /* Discard; may be needed on some platforms */
+}
+
+/**
+ * Enable entropy gathering
+ *
+ * @ret rc		Return status code
+ */
+static int rtc_entropy_enable ( void ) {
+
+	rtc_hook_isr();
+	enable_irq ( RTC_IRQ );
+	rtc_enable_int();
+
+	return 0;
+}
+
+/**
+ * Disable entropy gathering
+ *
+ */
+static void rtc_entropy_disable ( void ) {
+
+	rtc_disable_int();
+	disable_irq ( RTC_IRQ );
+	rtc_unhook_isr();
+}
+
+/**
+ * Measure a single RTC tick
+ *
+ * @ret delta		Length of RTC tick (in TSC units)
+ */
+uint8_t rtc_sample ( void ) {
+	uint32_t before;
+	uint32_t after;
+	uint32_t temp;
+
+	__asm__ __volatile__ (
+		REAL_CODE ( /* Enable interrupts */
+			    "sti\n\t"
+			    /* Wait for RTC interrupt */
+			    "movb %b2, %%cs:rtc_flag\n\t"
+			    "\n1:\n\t"
+			    "xchgb %b2, %%cs:rtc_flag\n\t" /* Serialize */
+			    "testb %b2, %b2\n\t"
+			    "jz 1b\n\t"
+			    /* Read "before" TSC */
+			    "rdtsc\n\t"
+			    /* Store "before" TSC on stack */
+			    "pushl %0\n\t"
+			    /* Wait for another RTC interrupt */
+			    "xorb %b2, %b2\n\t"
+			    "movb %b2, %%cs:rtc_flag\n\t"
+			    "\n1:\n\t"
+			    "xchgb %b2, %%cs:rtc_flag\n\t" /* Serialize */
+			    "testb %b2, %b2\n\t"
+			    "jz 1b\n\t"
+			    /* Read "after" TSC */
+			    "rdtsc\n\t"
+			    /* Retrieve "before" TSC on stack */
+			    "popl %1\n\t"
+			    /* Disable interrupts */
+			    "cli\n\t"
+			    )
+		: "=a" ( after ), "=d" ( before ), "=q" ( temp )
+		: "2" ( 0 ) );
+
+	return ( after - before );
+}
+
+PROVIDE_ENTROPY_INLINE ( rtc, min_entropy_per_sample );
+PROVIDE_ENTROPY ( rtc, entropy_enable, rtc_entropy_enable );
+PROVIDE_ENTROPY ( rtc, entropy_disable, rtc_entropy_disable );
+PROVIDE_ENTROPY_INLINE ( rtc, get_noise );

src/arch/x86/interface/pcbios/rtc_time.c

@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * RTC-based time source
+ *
+ */
+
+#include <stdint.h>
+#include <time.h>
+#include <rtc.h>
+#include <ipxe/time.h>
+
+/**
+ * Read RTC register
+ *
+ * @v address		Register address
+ * @ret data		Data
+ */
+static unsigned int rtc_readb ( int address ) {
+	outb ( address, CMOS_ADDRESS );
+	return inb ( CMOS_DATA );
+}
+
+/**
+ * Check if RTC update is in progress
+ *
+ * @ret is_busy		RTC update is in progress
+ */
+static int rtc_is_busy ( void ) {
+	return ( rtc_readb ( RTC_STATUS_A ) & RTC_STATUS_A_UPDATE_IN_PROGRESS );
+}
+
+/**
+ * Read RTC BCD register
+ *
+ * @v address		Register address
+ * @ret value		Value
+ */
+static unsigned int rtc_readb_bcd ( int address ) {
+	unsigned int bcd;
+
+	bcd = rtc_readb ( address );
+	return ( bcd - ( 6 * ( bcd >> 4 ) ) );
+}
+
+/**
+ * Read RTC time
+ *
+ * @ret time		Time, in seconds
+ */
+static time_t rtc_read_time ( void ) {
+	unsigned int status_b;
+	int is_binary;
+	int is_24hour;
+	unsigned int ( * read_component ) ( int address );
+	struct tm tm;
+	int is_pm;
+	unsigned int hour;
+	time_t time;
+
+	/* Wait for any in-progress update to complete */
+	while ( rtc_is_busy() ) {}
+
+	/* Determine RTC mode */
+	status_b = rtc_readb ( RTC_STATUS_B );
+	is_binary = ( status_b & RTC_STATUS_B_BINARY );
+	is_24hour = ( status_b & RTC_STATUS_B_24_HOUR );
+	read_component = ( is_binary ? rtc_readb : rtc_readb_bcd );
+
+	/* Read time values */
+	tm.tm_sec = read_component ( RTC_SEC );
+	tm.tm_min = read_component ( RTC_MIN );
+	hour = read_component ( RTC_HOUR );
+	if ( ! is_24hour ) {
+		is_pm = ( hour >= 80 );
+		hour = ( ( ( ( hour & 0x7f ) % 80 ) % 12 ) +
+			 ( is_pm ? 12 : 0 ) );
+	}
+	tm.tm_hour = hour;
+	tm.tm_mday = read_component ( RTC_MDAY );
+	tm.tm_mon = ( read_component ( RTC_MON ) - 1 );
+	tm.tm_year = ( read_component ( RTC_YEAR ) +
+		       100 /* Assume we are in the 21st century, since
+			    * this code was written in 2012 */ );
+
+	DBGC ( RTC_STATUS_A, "RTCTIME is %04d-%02d-%02d %02d:%02d:%02d "
+	       "(%s,%d-hour)\n", ( tm.tm_year + 1900 ), ( tm.tm_mon + 1 ),
+	       tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
+	       ( is_binary ? "binary" : "BCD" ), ( is_24hour ? 24 : 12 ) );
+
+	/* Convert to seconds since the Epoch */
+	time = mktime ( &tm );
+
+	return time;
+}
+
+/**
+ * Get current time in seconds
+ *
+ * @ret time		Time, in seconds
+ */
+static time_t rtc_now ( void ) {
+	time_t time = 0;
+	time_t last_time;
+
+	/* Read time until we get two matching values in a row, in
+	 * case we end up reading a corrupted value in the middle of
+	 * an update.
+	 */
+	do {
+		last_time = time;
+		time = rtc_read_time();
+	} while ( time != last_time );
+
+	return time;
+}
+
+PROVIDE_TIME ( rtc, time_now, rtc_now );

src/arch/x86/interface/pcbios/vesafb.c

@@ -0,0 +1,540 @@
+/*
+ * Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * VESA frame buffer console
+ *
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <limits.h>
+#include <realmode.h>
+#include <ipxe/console.h>
+#include <ipxe/io.h>
+#include <ipxe/ansicol.h>
+#include <ipxe/fbcon.h>
+#include <ipxe/vesafb.h>
+#include <config/console.h>
+
+/* Avoid dragging in BIOS console if not otherwise used */
+extern struct console_driver bios_console;
+struct console_driver bios_console __attribute__ (( weak ));
+
+/* Disambiguate the various error causes */
+#define EIO_FAILED __einfo_error ( EINFO_EIO_FAILED )
+#define EINFO_EIO_FAILED						\
+	__einfo_uniqify ( EINFO_EIO, 0x01,				\
+			  "Function call failed" )
+#define EIO_HARDWARE __einfo_error ( EINFO_EIO_HARDWARE )
+#define EINFO_EIO_HARDWARE						\
+	__einfo_uniqify ( EINFO_EIO, 0x02,				\
+			  "Not supported in current configuration" )
+#define EIO_MODE __einfo_error ( EINFO_EIO_MODE )
+#define EINFO_EIO_MODE							\
+	__einfo_uniqify ( EINFO_EIO, 0x03,				\
+			  "Invalid in current video mode" )
+#define EIO_VBE( code )							\
+	EUNIQ ( EINFO_EIO, (code), EIO_FAILED, EIO_HARDWARE, EIO_MODE )
+
+/* Set default console usage if applicable
+ *
+ * We accept either CONSOLE_FRAMEBUFFER or CONSOLE_VESAFB.
+ */
+#if ( defined ( CONSOLE_FRAMEBUFFER ) && ! defined ( CONSOLE_VESAFB ) )
+#define CONSOLE_VESAFB CONSOLE_FRAMEBUFFER
+#endif
+#if ! ( defined ( CONSOLE_VESAFB ) && CONSOLE_EXPLICIT ( CONSOLE_VESAFB ) )
+#undef CONSOLE_VESAFB
+#define CONSOLE_VESAFB ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
+#endif
+
+/** Character height */
+#define VESAFB_CHAR_HEIGHT 16
+
+/** Font corresponding to selected character width and height */
+#define VESAFB_FONT VBE_FONT_8x16
+
+/* Forward declaration */
+struct console_driver vesafb_console __console_driver;
+
+/** A VESA frame buffer */
+struct vesafb {
+	/** Frame buffer console */
+	struct fbcon fbcon;
+	/** Physical start address */
+	physaddr_t start;
+	/** Pixel geometry */
+	struct fbcon_geometry pixel;
+	/** Colour mapping */
+	struct fbcon_colour_map map;
+	/** Font definition */
+	struct fbcon_font font;
+	/** Character glyphs */
+	struct segoff glyphs;
+	/** Saved VGA mode */
+	uint8_t saved_mode;
+};
+
+/** The VESA frame buffer */
+static struct vesafb vesafb;
+
+/** Base memory buffer used for VBE calls */
+union vbe_buffer {
+	/** VBE controller information block */
+	struct vbe_controller_info controller;
+	/** VBE mode information block */
+	struct vbe_mode_info mode;
+};
+static union vbe_buffer __bss16 ( vbe_buf );
+#define vbe_buf __use_data16 ( vbe_buf )
+
+/**
+ * Convert VBE status code to iPXE status code
+ *
+ * @v status		VBE status code
+ * @ret rc		Return status code
+ */
+static int vesafb_rc ( unsigned int status ) {
+	unsigned int code;
+
+	if ( ( status & 0xff ) != 0x4f )
+		return -ENOTSUP;
+	code = ( ( status >> 8 ) & 0xff );
+	return ( code ? -EIO_VBE ( code ) : 0 );
+}
+
+/**
+ * Get character glyph
+ *
+ * @v character		Character
+ * @v glyph		Character glyph to fill in
+ */
+static void vesafb_glyph ( unsigned int character, uint8_t *glyph ) {
+	size_t offset = ( character * VESAFB_CHAR_HEIGHT );
+
+	copy_from_real ( glyph, vesafb.glyphs.segment,
+			 ( vesafb.glyphs.offset + offset ), VESAFB_CHAR_HEIGHT);
+}
+
+/**
+ * Get font definition
+ *
+ */
+static void vesafb_font ( void ) {
+
+	/* Get font information
+	 *
+	 * Working around gcc bugs is icky here.  The value we want is
+	 * returned in %ebp, but there's no way to specify %ebp in an
+	 * output constraint.  We can't put %ebp in the clobber list,
+	 * because this tends to cause random build failures on some
+	 * gcc versions.  We can't manually push/pop %ebp and return
+	 * the value via a generic register output constraint, because
+	 * gcc might choose to use %ebp to satisfy that constraint
+	 * (and we have no way to prevent it from so doing).
+	 *
+	 * Work around this hideous mess by using %ecx and %edx as the
+	 * output registers, since they get clobbered anyway.
+	 */
+	__asm__ __volatile__ ( REAL_CODE ( "pushw %%bp\n\t" /* gcc bug */
+					   "int $0x10\n\t"
+					   "movw %%es, %%cx\n\t"
+					   "movw %%bp, %%dx\n\t"
+					   "popw %%bp\n\t" /* gcc bug */ )
+			       : "=c" ( vesafb.glyphs.segment ),
+				 "=d" ( vesafb.glyphs.offset )
+			       : "a" ( VBE_GET_FONT ),
+				 "b" ( VESAFB_FONT ) );
+	DBGC ( &vbe_buf, "VESAFB has font %04x at %04x:%04x\n",
+	       VESAFB_FONT, vesafb.glyphs.segment, vesafb.glyphs.offset );
+	vesafb.font.height = VESAFB_CHAR_HEIGHT;
+	vesafb.font.glyph = vesafb_glyph;
+}
+
+/**
+ * Get VBE mode list
+ *
+ * @ret mode_numbers	Mode number list (terminated with VBE_MODE_END)
+ * @ret rc		Return status code
+ *
+ * The caller is responsible for eventually freeing the mode list.
+ */
+static int vesafb_mode_list ( uint16_t **mode_numbers ) {
+	struct vbe_controller_info *controller = &vbe_buf.controller;
+	userptr_t video_mode_ptr;
+	uint16_t mode_number;
+	uint16_t status;
+	size_t len;
+	int rc;
+
+	/* Avoid returning uninitialised data on error */
+	*mode_numbers = NULL;
+
+	/* Get controller information block */
+	controller->vbe_signature = 0;
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x10" )
+			       : "=a" ( status )
+			       : "a" ( VBE_CONTROLLER_INFO ),
+				 "D" ( __from_data16 ( controller ) )
+			       : "memory", "ebx", "edx" );
+	if ( ( rc = vesafb_rc ( status ) ) != 0 ) {
+		DBGC ( &vbe_buf, "VESAFB could not get controller information: "
+		       "[%04x] %s\n", status, strerror ( rc ) );
+		return rc;
+	}
+	if ( controller->vbe_signature != VBE_CONTROLLER_SIGNATURE ) {
+		DBGC ( &vbe_buf, "VESAFB invalid controller signature "
+		       "\"%c%c%c%c\"\n", ( controller->vbe_signature >> 0 ),
+		       ( controller->vbe_signature >> 8 ),
+		       ( controller->vbe_signature >> 16 ),
+		       ( controller->vbe_signature >> 24 ) );
+		DBGC_HDA ( &vbe_buf, 0, controller, sizeof ( *controller ) );
+		return -EINVAL;
+	}
+	DBGC ( &vbe_buf, "VESAFB found VBE version %d.%d with mode list at "
+	       "%04x:%04x\n", controller->vbe_major_version,
+	       controller->vbe_minor_version,
+	       controller->video_mode_ptr.segment,
+	       controller->video_mode_ptr.offset );
+
+	/* Calculate length of mode list */
+	video_mode_ptr = real_to_user ( controller->video_mode_ptr.segment,
+					controller->video_mode_ptr.offset );
+	len = 0;
+	do {
+		copy_from_user ( &mode_number, video_mode_ptr, len,
+				 sizeof ( mode_number ) );
+		len += sizeof ( mode_number );
+	} while ( mode_number != VBE_MODE_END );
+
+	/* Allocate and fill mode list */
+	*mode_numbers = malloc ( len );
+	if ( ! *mode_numbers )
+		return -ENOMEM;
+	copy_from_user ( *mode_numbers, video_mode_ptr, 0, len );
+
+	return 0;
+}
+
+/**
+ * Get video mode information
+ *
+ * @v mode_number	Mode number
+ * @ret rc		Return status code
+ */
+static int vesafb_mode_info ( unsigned int mode_number ) {
+	struct vbe_mode_info *mode = &vbe_buf.mode;
+	uint16_t status;
+	int rc;
+
+	/* Get mode information */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x10" )
+			       : "=a" ( status )
+			       : "a" ( VBE_MODE_INFO ),
+				 "c" ( mode_number ),
+				 "D" ( __from_data16 ( mode ) )
+			       : "memory" );
+	if ( ( rc = vesafb_rc ( status ) ) != 0 ) {
+		DBGC ( &vbe_buf, "VESAFB could not get mode %04x information: "
+		       "[%04x] %s\n", mode_number, status, strerror ( rc ) );
+		return rc;
+	}
+	DBGC ( &vbe_buf, "VESAFB mode %04x %dx%d %dbpp(%d:%d:%d:%d) model "
+	       "%02x [x%d]%s%s%s%s%s\n", mode_number, mode->x_resolution,
+	       mode->y_resolution, mode->bits_per_pixel, mode->rsvd_mask_size,
+	       mode->red_mask_size, mode->green_mask_size, mode->blue_mask_size,
+	       mode->memory_model, ( mode->number_of_image_pages + 1 ),
+	       ( ( mode->mode_attributes & VBE_MODE_ATTR_SUPPORTED ) ?
+		 "" : " [unsupported]" ),
+	       ( ( mode->mode_attributes & VBE_MODE_ATTR_TTY ) ?
+		 " [tty]" : "" ),
+	       ( ( mode->mode_attributes & VBE_MODE_ATTR_GRAPHICS ) ?
+		 "" : " [text]" ),
+	       ( ( mode->mode_attributes & VBE_MODE_ATTR_LINEAR ) ?
+		 "" : " [nonlinear]" ),
+	       ( ( mode->mode_attributes & VBE_MODE_ATTR_TRIPLE_BUF ) ?
+		 " [buf]" : "" ) );
+
+	return 0;
+}
+
+/**
+ * Set video mode
+ *
+ * @v mode_number	Mode number
+ * @ret rc		Return status code
+ */
+static int vesafb_set_mode ( unsigned int mode_number ) {
+	struct vbe_mode_info *mode = &vbe_buf.mode;
+	uint16_t status;
+	int rc;
+
+	/* Get mode information */
+	if ( ( rc = vesafb_mode_info ( mode_number ) ) != 0 )
+		return rc;
+
+	/* Record mode parameters */
+	vesafb.start = mode->phys_base_ptr;
+	vesafb.pixel.width = mode->x_resolution;
+	vesafb.pixel.height = mode->y_resolution;
+	vesafb.pixel.len = ( ( mode->bits_per_pixel + 7 ) / 8 );
+	vesafb.pixel.stride = mode->bytes_per_scan_line;
+	DBGC ( &vbe_buf, "VESAFB mode %04x has frame buffer at %08x\n",
+	       mode_number, mode->phys_base_ptr );
+
+	/* Initialise font colours */
+	vesafb.map.red_scale = ( 8 - mode->red_mask_size );
+	vesafb.map.green_scale = ( 8 - mode->green_mask_size );
+	vesafb.map.blue_scale = ( 8 - mode->blue_mask_size );
+	vesafb.map.red_lsb = mode->red_field_position;
+	vesafb.map.green_lsb = mode->green_field_position;
+	vesafb.map.blue_lsb = mode->blue_field_position;
+
+	/* Select this mode */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x10" )
+			       : "=a" ( status )
+			       : "a" ( VBE_SET_MODE ),
+				 "b" ( mode_number ) );
+	if ( ( rc = vesafb_rc ( status ) ) != 0 ) {
+		DBGC ( &vbe_buf, "VESAFB could not set mode %04x: [%04x] %s\n",
+		       mode_number, status, strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * Select video mode
+ *
+ * @v mode_numbers	Mode number list (terminated with VBE_MODE_END)
+ * @v min_width		Minimum required width (in pixels)
+ * @v min_height	Minimum required height (in pixels)
+ * @v min_bpp		Minimum required colour depth (in bits per pixel)
+ * @ret mode_number	Mode number, or negative error
+ */
+static int vesafb_select_mode ( const uint16_t *mode_numbers,
+				unsigned int min_width, unsigned int min_height,
+				unsigned int min_bpp ) {
+	struct vbe_mode_info *mode = &vbe_buf.mode;
+	int best_mode_number = -ENOENT;
+	unsigned int best_score = INT_MAX;
+	unsigned int score;
+	uint16_t mode_number;
+	int rc;
+
+	/* Find the first suitable mode */
+	while ( ( mode_number = *(mode_numbers++) ) != VBE_MODE_END ) {
+
+		/* Force linear mode variant */
+		mode_number |= VBE_MODE_LINEAR;
+
+		/* Get mode information */
+		if ( ( rc = vesafb_mode_info ( mode_number ) ) != 0 )
+			continue;
+
+		/* Skip unusable modes */
+		if ( ( mode->mode_attributes & ( VBE_MODE_ATTR_SUPPORTED |
+						 VBE_MODE_ATTR_GRAPHICS |
+						 VBE_MODE_ATTR_LINEAR ) ) !=
+		     ( VBE_MODE_ATTR_SUPPORTED | VBE_MODE_ATTR_GRAPHICS |
+		       VBE_MODE_ATTR_LINEAR ) ) {
+			continue;
+		}
+		if ( mode->memory_model != VBE_MODE_MODEL_DIRECT_COLOUR )
+			continue;
+
+		/* Skip modes not meeting the requirements */
+		if ( ( mode->x_resolution < min_width ) ||
+		     ( mode->y_resolution < min_height ) ||
+		     ( mode->bits_per_pixel < min_bpp ) ) {
+			continue;
+		}
+
+		/* Select this mode if it has the best (i.e. lowest)
+		 * score.  We choose the scoring system to favour
+		 * modes close to the specified width and height;
+		 * within modes of the same width and height we prefer
+		 * a higher colour depth.
+		 */
+		score = ( ( mode->x_resolution * mode->y_resolution ) -
+			  mode->bits_per_pixel );
+		if ( score < best_score ) {
+			best_mode_number = mode_number;
+			best_score = score;
+		}
+	}
+
+	if ( best_mode_number >= 0 ) {
+		DBGC ( &vbe_buf, "VESAFB selected mode %04x\n",
+		       best_mode_number );
+	} else {
+		DBGC ( &vbe_buf, "VESAFB found no suitable mode\n" );
+	}
+
+	return best_mode_number;
+}
+
+/**
+ * Restore video mode
+ *
+ */
+static void vesafb_restore ( void ) {
+	uint32_t discard_a;
+
+	/* Restore saved VGA mode */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x10" )
+			       : "=a" ( discard_a )
+			       : "a" ( VBE_SET_VGA_MODE | vesafb.saved_mode ) );
+	DBGC ( &vbe_buf, "VESAFB restored VGA mode %#02x\n",
+	       vesafb.saved_mode );
+}
+
+/**
+ * Initialise VESA frame buffer
+ *
+ * @v config		Console configuration, or NULL to reset
+ * @ret rc		Return status code
+ */
+static int vesafb_init ( struct console_configuration *config ) {
+	uint32_t discard_b;
+	uint16_t *mode_numbers;
+	int mode_number;
+	int rc;
+
+	/* Record current VGA mode */
+	__asm__ __volatile__ ( REAL_CODE ( "int $0x10" )
+			       : "=a" ( vesafb.saved_mode ), "=b" ( discard_b )
+			       : "a" ( VBE_GET_VGA_MODE ) );
+	DBGC ( &vbe_buf, "VESAFB saved VGA mode %#02x\n", vesafb.saved_mode );
+
+	/* Get VESA mode list */
+	if ( ( rc = vesafb_mode_list ( &mode_numbers ) ) != 0 )
+		goto err_mode_list;
+
+	/* Select mode */
+	if ( ( mode_number = vesafb_select_mode ( mode_numbers, config->width,
+						  config->height,
+						  config->depth ) ) < 0 ) {
+		rc = mode_number;
+		goto err_select_mode;
+	}
+
+	/* Set mode */
+	if ( ( rc = vesafb_set_mode ( mode_number ) ) != 0 )
+		goto err_set_mode;
+
+	/* Get font data */
+	vesafb_font();
+
+	/* Initialise frame buffer console */
+	if ( ( rc = fbcon_init ( &vesafb.fbcon, phys_to_user ( vesafb.start ),
+				 &vesafb.pixel, &vesafb.map, &vesafb.font,
+				 config ) ) != 0 )
+		goto err_fbcon_init;
+
+	free ( mode_numbers );
+	return 0;
+
+	fbcon_fini ( &vesafb.fbcon );
+ err_fbcon_init:
+ err_set_mode:
+	vesafb_restore();
+ err_select_mode:
+	free ( mode_numbers );
+ err_mode_list:
+	return rc;
+}
+
+/**
+ * Finalise VESA frame buffer
+ *
+ */
+static void vesafb_fini ( void ) {
+
+	/* Finalise frame buffer console */
+	fbcon_fini ( &vesafb.fbcon );
+
+	/* Restore saved VGA mode */
+	vesafb_restore();
+}
+
+/**
+ * Print a character to current cursor position
+ *
+ * @v character		Character
+ */
+static void vesafb_putchar ( int character ) {
+
+	fbcon_putchar ( &vesafb.fbcon, character );
+}
+
+/**
+ * Configure console
+ *
+ * @v config		Console configuration, or NULL to reset
+ * @ret rc		Return status code
+ */
+static int vesafb_configure ( struct console_configuration *config ) {
+	int rc;
+
+	/* Reset console, if applicable */
+	if ( ! vesafb_console.disabled ) {
+		vesafb_fini();
+		bios_console.disabled &= ~CONSOLE_DISABLED_OUTPUT;
+		ansicol_reset_magic();
+	}
+	vesafb_console.disabled = CONSOLE_DISABLED;
+
+	/* Do nothing more unless we have a usable configuration */
+	if ( ( config == NULL ) ||
+	     ( config->width == 0 ) || ( config->height == 0 ) ) {
+		return 0;
+	}
+
+	/* Initialise VESA frame buffer */
+	if ( ( rc = vesafb_init ( config ) ) != 0 )
+		return rc;
+
+	/* Mark console as enabled */
+	vesafb_console.disabled = 0;
+	bios_console.disabled |= CONSOLE_DISABLED_OUTPUT;
+
+	/* Set magic colour to transparent if we have a background picture */
+	if ( config->pixbuf )
+		ansicol_set_magic_transparent();
+
+	return 0;
+}
+
+/** VESA frame buffer console driver */
+struct console_driver vesafb_console __console_driver = {
+	.usage = CONSOLE_VESAFB,
+	.putchar = vesafb_putchar,
+	.configure = vesafb_configure,
+	.disabled = CONSOLE_DISABLED,
+};