| /* |
| * GRUB -- GRand Unified Bootloader |
| * Copyright (C) 1999,2000,2001,2002,2003,2005,2006,2007,2008,2009 Free Software Foundation, Inc. |
| * |
| * GRUB 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 3 of the License, or |
| * (at your option) any later version. |
| * |
| * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <config.h> |
| #include <grub/symbol.h> |
| #include <grub/machine/memory.h> |
| #include <grub/machine/kernel.h> |
| |
| .text |
| .code32 |
| .globl _start |
| _start: |
| jmp codestart |
| |
| . = _start + GRUB_KERNEL_MACHINE_CORE_ENTRY_ADDR |
| VARIABLE(grub_core_entry_addr) |
| .long 0 |
| VARIABLE(grub_kernel_image_size) |
| .long 0 |
| VARIABLE(grub_prefix) |
| /* to be filled by grub-mkimage */ |
| |
| /* |
| * Leave some breathing room for the prefix. |
| */ |
| |
| . = _start + GRUB_KERNEL_MACHINE_DATA_END |
| |
| codestart: |
| /* Relocate to low memory. First we figure out our location. |
| We will derive the rom start address from it. */ |
| call 1f |
| 1: popl %esi |
| |
| /* Rom size is a multiple of 64 kiB. With this we get the |
| value of `grub_core_entry_addr' in %esi. */ |
| xorw %si, %si |
| |
| /* ... which allows us to access `grub_kernel_image_size' |
| before relocation. */ |
| movl (grub_kernel_image_size - _start)(%esi), %ecx |
| |
| |
| movl $_start, %edi |
| cld |
| rep |
| movsb |
| ljmp $GRUB_MEMORY_MACHINE_PROT_MODE_CSEG, $1f |
| 1: |
| |
| #ifdef APPLE_CC |
| /* clean out the bss */ |
| bss_start_abs = ABS (bss_start) |
| bss_end_abs = ABS (bss_end) |
| |
| movl bss_start_abs, %edi |
| |
| /* compute the bss length */ |
| movl bss_end_abs, %ecx |
| subl %edi, %ecx |
| #else |
| /* clean out the bss */ |
| movl $BSS_START_SYMBOL, %edi |
| |
| /* compute the bss length */ |
| movl $END_SYMBOL, %ecx |
| subl %edi, %ecx |
| #endif |
| |
| /* clean out */ |
| xorl %eax, %eax |
| cld |
| rep |
| stosb |
| |
| /* |
| * Call the start of main body of C code. |
| */ |
| call EXT_C(grub_main) |
| |
| /* This should never happen. */ |
| jmp EXT_C(grub_stop) |
