| 39,8 → 39,6 |
|---|
| .ascii "PT_MODE_WRITABLE" |
| .byte 0 |
| |
| #define START_STACK (BOOT_OFFSET - BOOT_STACK_SIZE) |
| |
| .section K_TEXT_START, "ax" |
| |
| KTEXT=8 |
| 48,19 → 46,9 |
|---|
| |
| .code32 |
| .align 4 |
| .global multiboot_image_start |
| multiboot_header: |
| .long MULTIBOOT_HEADER_MAGIC |
| .long MULTIBOOT_HEADER_FLAGS |
| .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS) # checksum |
| .long multiboot_header |
| .long unmapped_ktext_start |
| .long 0 |
| .long 0 |
| .long multiboot_image_start |
| .global kernel_image_start |
| |
| multiboot_image_start: |
| movl $START_STACK, %esp # initialize stack pointer |
| kernel_image_start: |
| lgdt KA2PA(bootstrap_gdtr) # initialize Global Descriptor Table register |
| |
| movw $KDATA, %cx |
| 101,81 → 89,7 |
|---|
| |
| popl %eax |
| popl %ebx |
| cmpl $MULTIBOOT_LOADER_MAGIC, %eax # compare GRUB signature |
| je valid_boot |
| |
| xorl %ecx, %ecx # no memory size or map available |
| movl %ecx, e801memorysize |
| movl %ecx, e820counter |
| |
| jmp invalid_boot |
| |
| valid_boot: |
| |
| movl (%ebx), %eax # ebx = physical address of struct multiboot_info |
| |
| bt $0, %eax # mbi->flags[0] (mem_lower, mem_upper valid) |
| jc mem_valid |
| |
| xorl %ecx, %ecx |
| jmp mem_invalid |
| |
| mem_valid: |
| movl 4(%ebx), %ecx # mbi->mem_lower |
| addl 8(%ebx), %ecx # mbi->mem_upper |
| |
| mem_invalid: |
| movl %ecx, e801memorysize |
| |
| bt $3, %eax # mbi->flags[3] (mods_count, mods_addr valid) |
| jc mods_valid |
| |
| xorl %ecx, %ecx |
| movl %ecx, init |
| jmp mods_end |
| |
| mods_valid: |
| |
| movl 20(%ebx), %ecx # mbi->mods_count |
| movl %ecx, init |
| |
| cmpl $0, %ecx |
| je mods_end |
| |
| movl 24(%ebx), %esi # mbi->mods_addr |
| movl $init, %edi |
| |
| mods_loop: |
| |
| movl 0(%esi), %edx # mods->mod_start |
| addl $0x80000000, %edx |
| movl %edx, 4(%edi) |
| |
| movl 4(%esi), %edx |
| subl 0(%esi), %edx # mods->mod_end - mods->mod_start |
| movl %edx, 8(%edi) |
| |
| addl $16, %esi |
| addl $8 , %edi |
| |
| loop mods_loop |
| |
| mods_end: |
| |
| invalid_boot: |
| |
| #ifdef CONFIG_SMP |
| |
| # copy AP bootstrap routines below 1 MB |
| |
| movl $BOOT_OFFSET, %esi |
| movl $AP_BOOT_OFFSET, %edi |
| movl $_hardcoded_unmapped_size, %ecx |
| cld |
| rep movsb |
| |
| #endif |
| |
| call main_bsp # never returns |
| |
| cli |