#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
prefix_exit:
prefix_exit_end:
.previous
