#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