/* * GRUB -- GRand Unified Bootloader * Copyright (C) 1999,2000,2001,2002,2003,2005,2006,2007,2008 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 <grub/symbol.h> #include <grub/machine/memory.h> #include <grub/cpu/linux.h> #include <grub/cpu/kernel.h> #include <multiboot.h> #include <multiboot2.h> /* * Note: GRUB is compiled with the options -mrtd and -mregparm=3. * So the first three arguments are passed in %eax, %edx, and %ecx, * respectively, and if a function has a fixed number of arguments * and the number if greater than three, the function must return * with "ret $N" where N is ((the number of arguments) - 3) * 4. */ .file "startup.S" .text .globl start, _start start: _start: jmp codestart /* * This is a special data area at a fixed offset from the beginning. */ . = _start + GRUB_KERNEL_CPU_PREFIX VARIABLE(grub_prefix) /* to be filled by grub-mkimage */ /* * Leave some breathing room for the prefix. */ . = _start + GRUB_KERNEL_CPU_DATA_END /* * Support for booting GRUB from a Multiboot boot loader (e.g. GRUB itself). */ .p2align 2 /* force 4-byte alignment */ multiboot_header: /* magic */ .long 0x1BADB002 /* flags */ .long MULTIBOOT_MEMORY_INFO /* checksum */ .long -0x1BADB002 - MULTIBOOT_MEMORY_INFO codestart: cmpl $MULTIBOOT_MAGIC2, %eax jne 0f movl %ebx, EXT_C(startup_multiboot_info) 0: /* initialize the stack */ movl $GRUB_MEMORY_MACHINE_PROT_STACK, %esp /* jump to the main body of C code */ jmp EXT_C(grub_main) /* * prot_to_real and associated structures (but NOT real_to_prot, that is * only needed for BIOS gates). */ #include "../realmode.S" /* * Routines needed by Linux and Multiboot loaders. */ #include "../loader.S"