[x86_64] Add support for compilation as an x86_64 binary

Currently the only supported platform for x86_64 is EFI.

Building an EFI64 gPXE requires a version of gcc that supports
__attribute__((ms_abi)).  This currently means a development build of
gcc; the feature should be present when gcc 4.4 is released.

In the meantime; you can grab a suitable gcc tree from

  git://git.etherboot.org/scm/people/mcb30/gcc/.git

src/arch/x86/Makefile

@@ -0,0 +1,8 @@
+# Include common x86 headers
+#
+CFLAGS		+= -Iarch/x86/include
+
+# x86-specific directories containing source files
+#
+SRCDIRS		+= arch/x86/core
+SRCDIRS 	+= arch/x86/interface/efi

src/arch/x86/core/pcidirect.c

@@ -0,0 +1,45 @@
+/*
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <gpxe/io.h>
+#include <gpxe/pci.h>
+
+/** @file
+ *
+ * PCI configuration space access via Type 1 accesses
+ *
+ */
+
+/**
+ * Prepare for Type 1 PCI configuration space access
+ *
+ * @v pci		PCI device
+ * @v where	Location within PCI configuration space
+ */
+void pcidirect_prepare ( struct pci_device *pci, int where ) {
+	outl ( ( 0x80000000 | ( pci->bus << 16 ) | ( pci->devfn << 8 ) |
+		 ( where & ~3 ) ), PCIDIRECT_CONFIG_ADDRESS );
+}
+
+PROVIDE_PCIAPI_INLINE ( direct, pci_max_bus );
+PROVIDE_PCIAPI_INLINE ( direct, pci_read_config_byte );
+PROVIDE_PCIAPI_INLINE ( direct, pci_read_config_word );
+PROVIDE_PCIAPI_INLINE ( direct, pci_read_config_dword );
+PROVIDE_PCIAPI_INLINE ( direct, pci_write_config_byte );
+PROVIDE_PCIAPI_INLINE ( direct, pci_write_config_word );
+PROVIDE_PCIAPI_INLINE ( direct, pci_write_config_dword );

src/arch/x86/core/x86_string.c

@@ -0,0 +1,61 @@
+/*
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/** @file
+ *
+ * Optimised string operations
+ *
+ */
+
+#include <string.h>
+
+/**
+ * Copy memory area
+ *
+ * @v dest		Destination address
+ * @v src		Source address
+ * @v len		Length
+ * @ret dest		Destination address
+ */
+void * __memcpy ( void *dest, const void *src, size_t len ) {
+	void *edi = dest;
+	const void *esi = src;
+	int discard_ecx;
+
+	/* We often do large dword-aligned and dword-length block
+	 * moves.  Using movsl rather than movsb speeds these up by
+	 * around 32%.
+	 */
+	if ( len >> 2 ) {
+		__asm__ __volatile__ ( "rep movsl"
+				       : "=&D" ( edi ), "=&S" ( esi ),
+				         "=&c" ( discard_ecx )
+				       : "0" ( edi ), "1" ( esi ),
+				         "2" ( len >> 2 )
+				       : "memory" );
+	}
+	if ( len & 0x02 ) {
+		__asm__ __volatile__ ( "movsw" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	}
+	if ( len & 0x01 ) {
+		__asm__ __volatile__ ( "movsb" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	}
+	return dest;
+}

src/arch/x86/include/bits/pci_io.h

@@ -0,0 +1,13 @@
+#ifndef _BITS_PCI_IO_H
+#define _BITS_PCI_IO_H
+
+/** @file
+ *
+ * i386-specific PCI I/O API implementations
+ *
+ */
+
+#include <gpxe/pcibios.h>
+#include <gpxe/pcidirect.h>
+
+#endif /* _BITS_PCI_IO_H */

src/arch/x86/include/bits/string.h

@@ -0,0 +1,250 @@
+#ifndef ETHERBOOT_BITS_STRING_H
+#define ETHERBOOT_BITS_STRING_H
+/*
+ * Taken from Linux /usr/include/asm/string.h
+ * All except memcpy, memmove, memset and memcmp removed.
+ *
+ * Non-standard memswap() function added because it saves quite a bit
+ * of code (mbrown@fensystems.co.uk).
+ */
+
+/*
+ * This string-include defines all string functions as inline
+ * functions. Use gcc. It also assumes ds=es=data space, this should be
+ * normal. Most of the string-functions are rather heavily hand-optimized,
+ * see especially strtok,strstr,str[c]spn. They should work, but are not
+ * very easy to understand. Everything is done entirely within the register
+ * set, making the functions fast and clean. String instructions have been
+ * used through-out, making for "slightly" unclear code :-)
+ *
+ *		NO Copyright (C) 1991, 1992 Linus Torvalds,
+ *		consider these trivial functions to be PD.
+ */
+
+#define __HAVE_ARCH_MEMCPY
+
+extern void * __memcpy ( void *dest, const void *src, size_t len );
+
+#if 0
+static inline __attribute__ (( always_inline )) void *
+__memcpy ( void *dest, const void *src, size_t len ) {
+	int d0, d1, d2;
+	__asm__ __volatile__ ( "rep ; movsb"
+			       : "=&c" ( d0 ), "=&S" ( d1 ), "=&D" ( d2 )
+			       : "0" ( len ), "1" ( src ), "2" ( dest )
+			       : "memory" );
+	return dest; 
+}
+#endif
+
+static inline __attribute__ (( always_inline )) void *
+__constant_memcpy ( void *dest, const void *src, size_t len ) {
+	union {
+		uint32_t u32[2];
+		uint16_t u16[4];
+		uint8_t  u8[8];
+	} __attribute__ (( __may_alias__ )) *dest_u = dest;
+	const union {
+		uint32_t u32[2];
+		uint16_t u16[4];
+		uint8_t  u8[8];
+	} __attribute__ (( __may_alias__ )) *src_u = src;
+	const void *esi;
+	void *edi;
+
+	switch ( len ) {
+	case 0 : /* 0 bytes */
+		return dest;
+	/*
+	 * Single-register moves; these are always better than a
+	 * string operation.  We can clobber an arbitrary two
+	 * registers (data, source, dest can re-use source register)
+	 * instead of being restricted to esi and edi.  There's also a
+	 * much greater potential for optimising with nearby code.
+	 *
+	 */
+	case 1 : /* 4 bytes */
+		dest_u->u8[0]  = src_u->u8[0];
+		return dest;
+	case 2 : /* 6 bytes */
+		dest_u->u16[0] = src_u->u16[0];
+		return dest;
+	case 4 : /* 4 bytes */
+		dest_u->u32[0] = src_u->u32[0];
+		return dest;
+	/*
+	 * Double-register moves; these are probably still a win.
+	 *
+	 */
+	case 3 : /* 12 bytes */
+		dest_u->u16[0] = src_u->u16[0];
+		dest_u->u8[2]  = src_u->u8[2];
+		return dest;
+	case 5 : /* 10 bytes */
+		dest_u->u32[0] = src_u->u32[0];
+		dest_u->u8[4]  = src_u->u8[4];
+		return dest;
+	case 6 : /* 12 bytes */
+		dest_u->u32[0] = src_u->u32[0];
+		dest_u->u16[2] = src_u->u16[2];
+		return dest;
+	case 8 : /* 10 bytes */
+		dest_u->u32[0] = src_u->u32[0];
+		dest_u->u32[1] = src_u->u32[1];
+		return dest;
+	}
+
+	/* Even if we have to load up esi and edi ready for a string
+	 * operation, we can sometimes save space by using multiple
+	 * single-byte "movs" operations instead of loading up ecx and
+	 * using "rep movsb".
+	 *
+	 * "load ecx, rep movsb" is 7 bytes, plus an average of 1 byte
+	 * to allow for saving/restoring ecx 50% of the time.
+	 *
+	 * "movsl" and "movsb" are 1 byte each, "movsw" is two bytes.
+	 * (In 16-bit mode, "movsl" is 2 bytes and "movsw" is 1 byte,
+	 * but "movsl" moves twice as much data, so it balances out).
+	 *
+	 * The cutoff point therefore occurs around 26 bytes; the byte
+	 * requirements for each method are:
+	 *
+	 * len		   16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
+	 * #bytes (ecx)	    8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8
+	 * #bytes (no ecx)  4  5  6  7  5  6  7  8  6  7  8  9  7  8  9 10
+	 */
+
+	esi = src;
+	edi = dest;
+	
+	if ( len >= 26 )
+		return __memcpy ( dest, src, len );
+	
+	if ( len >= 6*4 )
+		__asm__ __volatile__ ( "movsl" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	if ( len >= 5*4 )
+		__asm__ __volatile__ ( "movsl" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	if ( len >= 4*4 )
+		__asm__ __volatile__ ( "movsl" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	if ( len >= 3*4 )
+		__asm__ __volatile__ ( "movsl" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	if ( len >= 2*4 )
+		__asm__ __volatile__ ( "movsl" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	if ( len >= 1*4 )
+		__asm__ __volatile__ ( "movsl" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	if ( ( len % 4 ) >= 2 )
+		__asm__ __volatile__ ( "movsw" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+	if ( ( len % 2 ) >= 1 )
+		__asm__ __volatile__ ( "movsb" : "=&D" ( edi ), "=&S" ( esi )
+				       : "0" ( edi ), "1" ( esi ) : "memory" );
+
+	return dest;
+}
+
+#define memcpy( dest, src, len )			\
+	( __builtin_constant_p ( (len) ) ?		\
+	  __constant_memcpy ( (dest), (src), (len) ) :	\
+	  __memcpy ( (dest), (src), (len) ) )
+
+#define __HAVE_ARCH_MEMMOVE
+static inline void * memmove(void * dest,const void * src, size_t n)
+{
+int d0, d1, d2;
+if (dest<src)
+__asm__ __volatile__(
+	"cld\n\t"
+	"rep\n\t"
+	"movsb"
+	: "=&c" (d0), "=&S" (d1), "=&D" (d2)
+	:"0" (n),"1" (src),"2" (dest)
+	: "memory");
+else
+__asm__ __volatile__(
+	"std\n\t"
+	"rep\n\t"
+	"movsb\n\t"
+	"cld"
+	: "=&c" (d0), "=&S" (d1), "=&D" (d2)
+	:"0" (n),
+	 "1" (n-1+(const char *)src),
+	 "2" (n-1+(char *)dest)
+	:"memory");
+return dest;
+}
+
+#define __HAVE_ARCH_MEMSET
+static inline void * memset(void *s, int c,size_t count)
+{
+int d0, d1;
+__asm__ __volatile__(
+	"cld\n\t"
+	"rep\n\t"
+	"stosb"
+	: "=&c" (d0), "=&D" (d1)
+	:"a" (c),"1" (s),"0" (count)
+	:"memory");
+return s;
+}
+
+#define __HAVE_ARCH_MEMSWAP
+static inline void * memswap(void *dest, void *src, size_t n)
+{
+int d0, d1, d2, d3;
+__asm__ __volatile__(
+	"\n1:\t"
+	"movb (%%edi),%%al\n\t"
+	"xchgb (%%esi),%%al\n\t"
+	"incl %%esi\n\t"
+	"stosb\n\t"
+	"loop 1b"
+	: "=&c" (d0), "=&S" (d1), "=&D" (d2), "=&a" (d3)
+	: "0" (n), "1" (src), "2" (dest)
+	: "memory" );
+return dest;
+}
+
+#define __HAVE_ARCH_STRNCMP
+static inline int strncmp(const char * cs,const char * ct,size_t count)
+{
+register int __res;
+int d0, d1, d2;
+__asm__ __volatile__(
+	"1:\tdecl %3\n\t"
+	"js 2f\n\t"
+	"lodsb\n\t"
+	"scasb\n\t"
+	"jne 3f\n\t"
+	"testb %%al,%%al\n\t"
+	"jne 1b\n"
+	"2:\txorl %%eax,%%eax\n\t"
+	"jmp 4f\n"
+	"3:\tsbbl %%eax,%%eax\n\t"
+	"orb $1,%%al\n"
+	"4:"
+		     :"=a" (__res), "=&S" (d0), "=&D" (d1), "=&c" (d2)
+		     :"1" (cs),"2" (ct),"3" (count));
+return __res;
+}
+
+#define __HAVE_ARCH_STRLEN
+static inline size_t strlen(const char * s)
+{
+int d0;
+register int __res;
+__asm__ __volatile__(
+	"repne\n\t"
+	"scasb\n\t"
+	"notl %0\n\t"
+	"decl %0"
+	:"=c" (__res), "=&D" (d0) :"1" (s),"a" (0), "0" (0xffffffff));
+return __res;
+}
+
+#endif /* ETHERBOOT_BITS_STRING_H */

src/arch/x86/include/gpxe/efi/efix86_nap.h

@@ -0,0 +1,16 @@
+#ifndef _GPXE_EFIX86_NAP_H
+#define _GPXE_EFIX86_NAP_H
+
+/** @file
+ *
+ * EFI CPU sleeping
+ *
+ */
+
+#ifdef NAP_EFIX86
+#define NAP_PREFIX_efix86
+#else
+#define NAP_PREFIX_efix86 __efix86_
+#endif
+
+#endif /* _GPXE_EFIX86_NAP_H */

src/arch/x86/include/gpxe/pcibios.h

@@ -0,0 +1,133 @@
+#ifndef _GPXE_PCIBIOS_H
+#define _GPXE_PCIBIOS_H
+
+#include <stdint.h>
+
+/** @file
+ *
+ * PCI configuration space access via PCI BIOS
+ *
+ */
+
+#ifdef PCIAPI_PCBIOS
+#define PCIAPI_PREFIX_pcbios
+#else
+#define PCIAPI_PREFIX_pcbios __pcbios_
+#endif
+
+struct pci_device;
+
+#define PCIBIOS_INSTALLATION_CHECK	0xb1010000
+#define PCIBIOS_READ_CONFIG_BYTE	0xb1080000
+#define PCIBIOS_READ_CONFIG_WORD	0xb1090000
+#define PCIBIOS_READ_CONFIG_DWORD	0xb10a0000
+#define PCIBIOS_WRITE_CONFIG_BYTE	0xb10b0000
+#define PCIBIOS_WRITE_CONFIG_WORD	0xb10c0000
+#define PCIBIOS_WRITE_CONFIG_DWORD	0xb10d0000
+
+extern int pcibios_read ( struct pci_device *pci, uint32_t command,
+			  uint32_t *value );
+extern int pcibios_write ( struct pci_device *pci, uint32_t command,
+			   uint32_t value );
+
+/**
+ * Read byte from PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( pcbios, pci_read_config_byte ) ( struct pci_device *pci,
+						 unsigned int where,
+						 uint8_t *value ) {
+	uint32_t tmp;
+	int rc;
+
+	rc = pcibios_read ( pci, PCIBIOS_READ_CONFIG_BYTE | where, &tmp );
+	*value = tmp;
+	return rc;
+}
+
+/**
+ * Read word from PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( pcbios, pci_read_config_word ) ( struct pci_device *pci,
+						 unsigned int where,
+						 uint16_t *value ) {
+	uint32_t tmp;
+	int rc;
+
+	rc = pcibios_read ( pci, PCIBIOS_READ_CONFIG_WORD | where, &tmp );
+	*value = tmp;
+	return rc;
+}
+
+/**
+ * Read dword from PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( pcbios, pci_read_config_dword ) ( struct pci_device *pci,
+						  unsigned int where,
+						  uint32_t *value ) {
+	return pcibios_read ( pci, PCIBIOS_READ_CONFIG_DWORD | where, value );
+}
+
+/**
+ * Write byte to PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( pcbios, pci_write_config_byte ) ( struct pci_device *pci,
+						  unsigned int where,
+						  uint8_t value ) {
+	return pcibios_write ( pci, PCIBIOS_WRITE_CONFIG_BYTE | where, value );
+}
+
+/**
+ * Write word to PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( pcbios, pci_write_config_word ) ( struct pci_device *pci,
+						  unsigned int where,
+						  uint16_t value ) {
+	return pcibios_write ( pci, PCIBIOS_WRITE_CONFIG_WORD | where, value );
+}
+
+/**
+ * Write dword to PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( pcbios, pci_write_config_dword ) ( struct pci_device *pci,
+						   unsigned int where,
+						   uint32_t value ) {
+	return pcibios_write ( pci, PCIBIOS_WRITE_CONFIG_DWORD | where, value);
+}
+
+#endif /* _GPXE_PCIBIOS_H */

src/arch/x86/include/gpxe/pcidirect.h

@@ -0,0 +1,139 @@
+#ifndef _PCIDIRECT_H
+#define _PCIDIRECT_H
+
+#include <stdint.h>
+#include <gpxe/io.h>
+
+#ifdef PCIAPI_DIRECT
+#define PCIAPI_PREFIX_direct
+#else
+#define PCIAPI_PREFIX_direct __direct_
+#endif
+
+/** @file
+ *
+ * PCI configuration space access via Type 1 accesses
+ *
+ */
+
+#define PCIDIRECT_CONFIG_ADDRESS	0xcf8
+#define PCIDIRECT_CONFIG_DATA		0xcfc
+
+struct pci_device;
+
+extern void pcidirect_prepare ( struct pci_device *pci, int where );
+
+/**
+ * Determine maximum PCI bus number within system
+ *
+ * @ret max_bus		Maximum bus number
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( direct, pci_max_bus ) ( void ) {
+	/* No way to work this out via Type 1 accesses */
+	return 0xff;
+}
+
+/**
+ * Read byte from PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( direct, pci_read_config_byte ) ( struct pci_device *pci,
+						 unsigned int where,
+						 uint8_t *value ) {
+	pcidirect_prepare ( pci, where );
+	*value = inb ( PCIDIRECT_CONFIG_DATA + ( where & 3 ) );
+	return 0;
+}
+
+/**
+ * Read word from PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( direct, pci_read_config_word ) ( struct pci_device *pci,
+						 unsigned int where,
+						 uint16_t *value ) {
+	pcidirect_prepare ( pci, where );
+	*value = inw ( PCIDIRECT_CONFIG_DATA + ( where & 2 ) );
+	return 0;
+}
+
+/**
+ * Read dword from PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( direct, pci_read_config_dword ) ( struct pci_device *pci,
+						  unsigned int where,
+						  uint32_t *value ) {
+	pcidirect_prepare ( pci, where );
+	*value = inl ( PCIDIRECT_CONFIG_DATA );
+	return 0;
+}
+
+/**
+ * Write byte to PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( direct, pci_write_config_byte ) ( struct pci_device *pci,
+						  unsigned int where,
+						  uint8_t value ) {
+	pcidirect_prepare ( pci, where );
+	outb ( value, PCIDIRECT_CONFIG_DATA + ( where & 3 ) );
+	return 0;
+}
+
+/**
+ * Write word to PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( direct, pci_write_config_word ) ( struct pci_device *pci,
+						  unsigned int where,
+						  uint16_t value ) {
+	pcidirect_prepare ( pci, where );
+	outw ( value, PCIDIRECT_CONFIG_DATA + ( where & 2 ) );
+	return 0;
+}
+
+/**
+ * Write dword to PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __always_inline int
+PCIAPI_INLINE ( direct, pci_write_config_dword ) ( struct pci_device *pci,
+						   unsigned int where,
+						   uint32_t value ) {
+	pcidirect_prepare ( pci, where );
+	outl ( value, PCIDIRECT_CONFIG_DATA );
+	return 0;
+}
+
+#endif /* _PCIDIRECT_H */

src/arch/x86/interface/efi/efix86_nap.c

@@ -0,0 +1,46 @@
+/*
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <gpxe/nap.h>
+#include <gpxe/efi/efi.h>
+
+/** @file
+ *
+ * gPXE CPU sleeping API for EFI
+ *
+ */
+
+/**
+ * Sleep until next interrupt
+ *
+ */
+static void efix86_cpu_nap ( void ) {
+	/*
+	 * I can't find any EFI API that allows us to put the CPU to
+	 * sleep.  The CpuSleep() function is defined in CpuLib.h, but
+	 * isn't part of any exposed protocol so we have no way to
+	 * call it.
+	 *
+	 * The EFI shell doesn't seem to bother sleeping the CPU; it
+	 * just sits there idly burning power.
+	 *
+	 */
+	__asm__ __volatile__ ( "hlt" );
+}
+
+PROVIDE_NAP ( efix86, cpu_nap, efix86_cpu_nap );