[efi] Add EFI image format and basic runtime environment

We have EFI APIs for CPU I/O, PCI I/O, timers, console I/O, user
access and user memory allocation.

EFI executables are created using the vanilla GNU toolchain, with the
EXE header handcrafted in assembly and relocations generated by a
custom efilink utility.

src/arch/i386/Makefile

@@ -64,6 +64,7 @@ SRCDIRS		+= arch/i386/drivers/net
 SRCDIRS		+= arch/i386/interface/pcbios
 SRCDIRS		+= arch/i386/interface/pxe
 SRCDIRS 	+= arch/i386/interface/syslinux
+SRCDIRS 	+= arch/i386/interface/efi
 
 # The various xxx_loader.c files are #included into core/loader.c and
 # should not be compiled directly.

src/arch/i386/Makefile.efi

@@ -0,0 +1,24 @@
+# -*- makefile -*- : Force emacs to use Makefile mode
+
+# The EFI linker script
+#
+LDSCRIPT	= arch/i386/scripts/efi.lds
+
+# Use a relocatable link; we perform final relocations in the efilink utility.
+#
+LDFLAGS		+= -r -d -S
+
+# Media types.
+#
+NON_AUTO_MEDIA	+= efi
+
+# Rule for building EFI files
+#
+$(BIN)/%.efi.tmp-reloc : $(BIN)/%.efi.tmp $(EFILINK)
+	$(QM)$(ECHO) "  [EFILINK] $@"
+	$(Q)$(LD) -e 0 -o /dev/null $< # Check for unresolved symbols
+	$(Q)$(EFILINK) $< $@
+
+$(BIN)/%.efi : $(BIN)/%.efi.tmp-reloc
+	$(QM)$(ECHO) "  [FINISH] $@"
+	$(Q)$(OBJCOPY) -Obinary $< $@

src/arch/i386/include/bits/nap.h

@@ -8,5 +8,6 @@
  */
 
 #include <gpxe/bios_nap.h>
+#include <gpxe/efi/efix86_nap.h>
 
 #endif /* _BITS_MAP_H */

src/arch/i386/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/i386/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 );

src/arch/i386/prefix/efiprefix.S

@@ -0,0 +1,175 @@
+	.text
+	.code32
+	.arch i386
+	.section ".prefix", "a", @progbits
+	.org 0x00
+
+	/* DOS (.com) header
+	 *
+	 * EFI executables seem to leave most of this empty
+	 */
+mzhdr:
+	.ascii	"MZ"		/* Magic number */
+	.word	0		/* Bytes on last page of file */
+	.word	0		/* Pages in file */
+	.word	0		/* Relocations */
+	.word	0		/* Size of header in paragraphs */
+	.word	0		/* Minimum extra paragraphs needed */
+	.word	0		/* Maximum extra paragraphs needed */
+	.word	0		/* Initial (relative) SS value */
+	.word	0		/* Initial SP value */
+	.word	0		/* "Checksum" */
+	.word	0		/* Initial IP value */
+	.word	0		/* Initial (relative) CS value */
+	.word	0		/* File address of relocation table */
+	.word	0		/* Ovesrlay number */
+	.word	0, 0, 0, 0	/* Reserved words */
+	.word	0		/* OEM identifier (for e_oeminfo) */
+	.word	0		/* OEM information; e_oemid specific */
+	.word	0, 0, 0, 0, 0	/* Reserved words */
+	.word	0, 0, 0, 0, 0	/* Reserved words */
+	.long	pehdr_lma	/* File address of new exe header */
+	.size	mzhdr, . - mzhdr
+
+	/* PE header */
+	.org	0xc0 /* For compatibility with MS toolchain */
+pehdr:
+	.ascii	"PE\0\0"	/* Magic number */
+	.word	0x014c		/* CPU architecture: i386 */
+	.word	num_pe_sections	/* Number of sections */
+	.long	0x10d1a884	/* Timestamp */
+	.long	0		/* Symbol table */
+	.long	0		/* Number of symbols */
+	.word	opthdr_size	/* Size of optional header */
+	.word	0x2102		/* Characteristics */
+	.size	pehdr, . - pehdr
+	.equ	pehdr_lma, pehdr - mzhdr
+
+	/* "Optional" header */
+opthdr:
+	.word	0x010b		/* Magic number */
+	.byte	0		/* Linker major version number */
+	.byte	0		/* Linker minor version number */
+	.long	_text_filesz	/* Size of text section */
+	.long	_data_filesz	/* Size of data section */
+	.long	_bss_filesz	/* Size of bss section */
+	.long	efi_entry_lma	/* Entry point */
+	.long	_text_lma	/* Text section start RVA */
+	.long	_data_lma	/* Data section start RVA */
+	.long	0		/* Image base address */
+	.long	_max_align	/* Section alignment */
+	.long	_max_align	/* File alignment */
+	.word	0		/* Operating system major version number */
+	.word	0		/* Operating system minor version number */
+	.word	0		/* Image major version number */
+	.word	0		/* Image minor version number */
+	.word	0		/* Subsystem major version number */
+	.word	0		/* Subsystem minor version number */
+	.long	0		/* Reserved */
+	.long	_filesz		/* Total image size */
+	.long	_prefix_filesz	/* Total header size */
+	.long	0		/* "Checksum" */
+	.word	0x0a		/* Subsystem: EFI */
+	.word	0		/* DLL characteristics */
+	.long	0		/* Size of stack reserve */
+	.long	0		/* Size of stack commit */
+	.long	0		/* Size of heap reserve */
+	.long	0		/* Size of heap commit */
+	.long	0		/* Loader flags */
+	.long	16		/* Number of data directory entries */
+	.long	0, 0		/* Export directory */
+	.long	0, 0		/* Import directory */
+	.long	0, 0		/* Resource directory */
+	.long	0, 0		/* Exception directory */
+	.long	0, 0		/* Security directory */
+	.long	_reloc_lma, _reloc_filesz /* Base relocation directory */
+	.long	debugdir_lma, debugdir_size /* Debug directory */
+	.long	0, 0		/* Description directory */
+	.long	0, 0		/* Special directory */
+	.long	0, 0		/* Thread storage directory */
+	.long	0, 0		/* Load configuration directory */
+	.long	0, 0		/* Bound import directory */
+	.long	0, 0		/* Import address table directory */
+	.long	0, 0		/* Delay import directory */
+	.long	0, 0		/* Reserved */
+	.long	0, 0		/* Reserved */
+	.size	opthdr, . - opthdr
+	.equ	opthdr_size, . - opthdr
+
+	/* PE sections */
+pe_sections:
+text_section:
+	.asciz	".text"		/* Section name */
+	.align	8
+	.long	_text_filesz	/* Section size */
+	.long	_text_lma	/* Relative Virtual Address */
+	.long	_text_filesz	/* Section size (rounded up) */
+	.long	_text_lma	/* Pointer to raw data */
+	.long	0		/* Link-time relocations */
+	.long	0		/* Line numbers */
+	.word	0		/* Number of link-time relocations */
+	.word	0		/* Number of line numbers */
+	.long	0x68000020	/* Characteristics */
+rodata_section:
+	.asciz	".rodata"	/* Section name */
+	.align	8
+	.long	_rodata_filesz	/* Section size */
+	.long	_rodata_lma	/* Relative Virtual Address */
+	.long	_rodata_filesz	/* Section size (rounded up) */
+	.long	_rodata_lma	/* Pointer to raw data */
+	.long	0		/* Link-time relocations */
+	.long	0		/* Line numbers */
+	.word	0		/* Number of link-time relocations */
+	.word	0		/* Number of line numbers */
+	.long	0x48000040	/* Characteristics */
+data_section:
+	.asciz	".data"		/* Section name */
+	.align	8
+	.long	_data_filesz	/* Section size */
+	.long	_data_lma	/* Relative Virtual Address */
+	.long	_data_filesz	/* Section size (rounded up) */
+	.long	_data_lma	/* Pointer to raw data */
+	.long	0		/* Link-time relocations */
+	.long	0		/* Line numbers */
+	.word	0		/* Number of link-time relocations */
+	.word	0		/* Number of line numbers */
+	.long	0xc8000040	/* Characteristics */
+reloc_section:
+	.asciz	".reloc"	/* Section name */
+	.align	8
+	.long	_reloc_filesz	/* Section size */
+	.long	_reloc_lma	/* Relative Virtual Address */
+	.long	_reloc_filesz	/* Section size (rounded up) */
+	.long	_reloc_lma	/* Pointer to raw data */
+	.long	0		/* Link-time relocations */
+	.long	0		/* Line numbers */
+	.word	0		/* Number of link-time relocations */
+	.word	0		/* Number of line numbers */
+	.long	0x42000040	/* Characteristics */
+
+pe_sections_end:
+	.size	pe_sections, . - pe_sections
+	.equ	num_pe_sections, ( ( . - pe_sections ) / 0x28 )
+
+	/* Debug directory */
+	.section ".rodata"
+	.globl	debugdir
+debugdir:
+	.long	0		/* Characteristics */
+	.long	0x10d1a884	/* Timestamp */
+	.word	0		/* Major version */
+	.word	0		/* Minor version */
+	.long	0x02		/* RSDS? */
+	.long	codeview_rsds_size /* Size of data */
+	.long	codeview_rsds_lma /* RVA */
+	.long	codeview_rsds_lma /* File offset */
+	.size	debugdir, . - debugdir
+	.equ	debugdir_size, . - debugdir
+	/* Codeview structure */
+	.globl	codeview_rsds
+codeview_rsds:
+	.ascii	"RSDS"		/* Magic number */
+	.long	0, 0, 0, 0, 0	/* Unused by EFI */
+	.asciz	"efiprefix.pdb"
+	.size	codeview_rsds, . - codeview_rsds
+	.equ	codeview_rsds_size, . - codeview_rsds

src/arch/i386/scripts/efi.lds

@@ -0,0 +1,174 @@
+/* -*- sh -*- */
+
+/*
+ * Linker script for EFI images
+ *
+ */
+
+EXTERN ( efi_entry )
+
+SECTIONS {
+
+    /* The file starts at a virtual address of zero, and sections are
+     * contiguous.  Each section is aligned to at least _max_align,
+     * which defaults to 32.  Load addresses are equal to virtual
+     * addresses.
+     */
+
+    . = 0;
+    PROVIDE ( _max_align = 32 );
+
+    /*
+     * The prefix
+     *
+     */
+
+    .prefix : AT ( _prefix_lma ) {
+	_prefix = .;
+	*(.prefix)
+	*(.prefix.*)
+	_mprefix = .;
+    } .prefix_bss (NOLOAD) : {
+	_eprefix = .;
+    }
+    _prefix_filesz	= ABSOLUTE ( _mprefix - _prefix );
+    _prefix_memsz	= ABSOLUTE ( _eprefix - _prefix );
+
+    /*
+     * The text section
+     *
+     */
+
+    . = ALIGN ( _max_align );
+    .text : AT ( _text_lma ) {
+	_text = .;
+	*(.text)
+	*(.text.*)
+	_mtext = .;
+    } .text_bss (NOLOAD) : {
+	_etext = .;
+    }
+    _text_filesz	= ABSOLUTE ( _mtext - _text );
+    _text_memsz		= ABSOLUTE ( _etext - _text );
+
+    /*
+     * The rodata section
+     *
+     */
+
+    . = ALIGN ( _max_align );
+    .rodata : AT ( _rodata_lma ) {
+	_rodata = .;
+	*(.rodata)
+	*(.rodata.*)
+	_mrodata = .;
+    } .rodata_bss (NOLOAD) : {
+	_erodata = .;
+    }
+    _rodata_filesz	= ABSOLUTE ( _mrodata - _rodata );
+    _rodata_memsz	= ABSOLUTE ( _erodata - _rodata );
+
+    /*
+     * The data section
+     *
+     */
+
+    . = ALIGN ( _max_align );
+    .data : AT ( _data_lma ) {
+	_data = .;
+	*(.data)
+	*(.data.*)
+	*(SORT(.tbl.*))		/* Various tables.  See include/tables.h */
+	/* EFI seems to not support proper bss sections */
+	*(.bss)
+	*(.bss.*)
+	*(COMMON)
+	*(.stack)
+	*(.stack.*)
+	_mdata = .;
+    } .data_bss (NOLOAD) : {
+	_edata = .;
+    }
+    _data_filesz	= ABSOLUTE ( _mdata - _data );
+    _data_memsz		= ABSOLUTE ( _edata - _data );
+
+    /*
+     * The bss section
+     *
+     */
+
+    . = ALIGN ( _max_align );
+    .bss : AT ( _bss_lma ) {
+	_bss = .;
+	/* EFI seems to not support proper bss sections */
+	_mbss = .;
+    } .bss_bss (NOLOAD) : {
+	_ebss = .;
+    }
+    _bss_filesz		= ABSOLUTE ( _mbss - _bss );
+    _bss_memsz		= ABSOLUTE ( _ebss - _bss );
+
+    /*
+     * The reloc section
+     *
+     */
+
+    . = ALIGN ( _max_align );
+    .reloc : AT ( _reloc_lma ) {
+	_reloc = .;
+	/* Provide some dummy contents to force ld to include this
+	 * section.  It will be created by the efilink utility.
+	 */
+	. += 1;
+	_mreloc = .;
+    } .reloc_bss (NOLOAD) : {
+	_ereloc = .;
+    }
+    _reloc_filesz	= ABSOLUTE ( _mreloc - _reloc );
+    _reloc_memsz	= ABSOLUTE ( _ereloc - _reloc );
+
+    _filesz		= ABSOLUTE ( . );
+
+    /*
+     * Weak symbols that need zero values if not otherwise defined
+     *
+     */
+
+    .weak 0x0 : {
+	_weak = .;
+	*(.weak)
+	_eweak = .;
+    }
+    _assert = ASSERT ( ( _weak == _eweak ), ".weak is non-zero length" );
+
+    /*
+     * Dispose of the comment and note sections to make the link map
+     * easier to read
+     *
+     */
+
+    /DISCARD/ : {
+	*(.comment)
+	*(.note)
+    }
+
+    /*
+     * Load address calculations.
+     *
+     */
+
+    _prefix_lma		= ABSOLUTE ( _prefix );
+    _text_lma		= ABSOLUTE ( _text );
+    _rodata_lma		= ABSOLUTE ( _rodata );
+    _data_lma		= ABSOLUTE ( _data );
+    _bss_lma		= ABSOLUTE ( _bss );
+    _reloc_lma		= ABSOLUTE ( _reloc );
+
+    /*
+     * Load addresses required by the prefix
+     *
+     */
+    efi_entry_lma	= ABSOLUTE ( efi_entry );
+    debugdir_lma	= ABSOLUTE ( debugdir );
+    codeview_rsds_lma	= ABSOLUTE ( codeview_rsds );
+}