Initial revision

1 files changed, 163 insertions, 0 deletions

diff --git a/src/arch/i386/prefix/lmelf_prefix.S b/src/arch/i386/prefix/lmelf_prefix.S
new file mode 100644
index 00000000..7488f452
--- /dev/null
+++ b/src/arch/i386/prefix/lmelf_prefix.S
@@ -0,0 +1,163 @@
+#include "elf.h"
+	.arch sledgehammer
+	.code32
+	.equ	FLAT_CODE_SEG,_pmcs-_gdt
+	.equ	FLAT_DATA_SEG,_pmds-_gdt
+	.equ	MSR_K6_EFER,   0xC0000080
+	.equ	EFER_LME,      0x00000100
+	.equ	X86_CR4_PAE,   0x00000020
+	.equ	CR0_PG,        0x80000000
+
+	.section ".prefix", "ax", @progbits
+
+#define LOAD_ADDR 0x10000
+		
+	/* ELF Header */
+	.globl elf_header
+elf_header:	
+e_ident:	.byte	0x7f, 'E', 'L', 'F', 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0
+e_type:		.short	ET_EXEC
+e_machine:	.short	EM_X86_64
+e_version:	.long	1
+e_entry:	.long	LOAD_ADDR + elf_start - elf_header
+e_phoff:	.long	elf_program_header - elf_header
+e_shoff:	.long	0
+e_flags:	.long	0
+e_ehsize:	.short	elf_header_end - elf_header
+e_phentsize:	.short	ELF32_PHDR_SIZE
+e_phnum:	.short	(elf_program_header_end - elf_program_header)/ELF32_PHDR_SIZE
+e_shentsize:	.short	0
+e_shnum:	.short	0
+e_shstrndx:	.short	0
+elf_header_end:
+	
+elf_program_header:
+phdr1_p_type:	.long	PT_NOTE
+phdr1_p_offset:	.long	elf_note - elf_header
+phdr1_p_vaddr:	.long	elf_note
+phdr1_p_paddr:	.long	elf_note
+phdr1_p_filesz:	.long	elf_note_end - elf_note
+phdr1_p_memsz:	.long	elf_note_end - elf_note
+phdr1_p_flags:	.long	PF_R | PF_W | PF_X
+phdr1_p_align:	.long	0
+
+/* The decompressor */
+phdr2_p_type:	.long	PT_LOAD
+phdr2_p_offset:	.long	0
+phdr2_p_vaddr:	.long	elf_header
+phdr2_p_paddr:	.long	LOAD_ADDR
+phdr2_p_filesz:	.long	_verbatim_size
+phdr2_p_memsz:	.long	_image_size
+phdr2_p_flags:	.long	PF_R | PF_W | PF_X
+phdr2_p_align:	.long	16
+
+elf_program_header_end:
+
+	.globl elf_note
+elf_note:
+	.balign 4
+	.int 2f - 1f
+	.int 4f - 3f
+	.int EIN_PROGRAM_NAME
+1:	.asciz "ELFBoot"
+2:
+	.balign 4
+3:	
+	.asciz "Etherboot"
+4:
+
+
+	.balign 4
+	.int 2f - 1f
+	.int 4f - 3f
+	.int EIN_PROGRAM_VERSION
+1:	.asciz "ELFBoot"
+2:
+	.balign 4
+3:	
+	.asciz VERSION
+4:
+
+#if 0
+	.balign 4
+	.int 2f - 1f
+	.int 4f - 3f
+	.int EIN_PROGRAM_CHECKSUM
+1:	.asciz "ELFBoot"
+2:
+	.balign 4
+3:	
+	.word 0
+4:
+#endif
+	.balign 4
+elf_note_end:
+
+elf_start:
+	.code64
+	/* Reload the gdt to something I know */
+	leaq	_gdt(%rip), %rax
+	movq	%rax, 0x02 + gdtptr(%rip)
+	lgdt	gdtptr(%rip)
+
+	/* Enter 32bit compatibility mode */
+	leaq	elf_start32(%rip), %rax
+	movl	%eax, 0x00 + elf_start32_addr(%rip)
+	ljmp	*elf_start32_addr(%rip)
+
+elf_start32:	
+	.code32
+	/* Reload the data segments */
+	movl	$FLAT_DATA_SEG, %eax
+	movl	%eax, %ds
+	movl	%eax, %es
+	movl	%eax, %ss
+	
+	/* Disable paging */
+	movl	%cr0, %eax
+	andl	$~CR0_PG, %eax
+	movl	%eax, %cr0
+
+	/* Disable long mode */
+	movl	$MSR_K6_EFER, %ecx
+	rdmsr
+	andl	$~EFER_LME, %eax
+	wrmsr
+
+	/* Disable PAE */
+	movl	%cr4, %eax
+	andl	$~X86_CR4_PAE, %eax
+	movl	%eax, %cr4
+
+	/* Save the first argument */
+	pushl	%ebx
+	jmp	_start
+
+gdtptr:	
+	.word	_gdt_end - _gdt -1
+	.long	_gdt
+	.long	0
+_gdt:
+elf_start32_addr:
+	.long	elf_start32
+	.long	FLAT_CODE_SEG
+_pmcs:
+	/* 32 bit protected mode code segment, base 0 */
+	.word	0xffff,0
+	.byte	0,0x9f,0xcf,0
+
+_pmds:
+	/* 32 bit protected mode data segment, base 0 */
+	.word	0xffff,0
+	.byte	0,0x93,0xcf,0
+_gdt_end:	
+
+
+	/* Dummy routines to satisfy the build */
+	.section ".text16", "ax", @progbits
+	.globl	prefix_exit
+prefix_exit:
+
+	.globl	prefix_exit_end
+prefix_exit_end:
+	.previous