/* boot.S - bootstrap the kernel */ /* Copyright (C) 1999, 2001 Free Software Foundation, Inc. This program 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 2 of the License, or (at your option) any later version. This program 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 this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #define ASM 1 #include <multiboot.h> .text .globl start, _start start: _start: jmp multiboot_entry /* Align 32 bits boundary. */ .align 4 /* Multiboot header. */ multiboot_header: /* magic */ .long MULTIBOOT_HEADER_MAGIC /* flags */ .long MULTIBOOT_HEADER_FLAGS /* checksum */ .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS) #ifndef __ELF__ /* header_addr */ .long multiboot_header /* load_addr */ .long _start /* load_end_addr */ .long _edata /* bss_end_addr */ .long _end /* entry_addr */ .long multiboot_entry #endif /* ! __ELF__ */ multiboot_entry: /* Initialize the stack pointer. */ movl $(stack + STACK_SIZE), %esp /* Reset EFLAGS. */ pushl $0 popf /* Push the pointer to the Multiboot information structure. */ pushl %ebx /* Push the magic value. */ pushl %eax /* Now enter the C main function... */ call EXT_C(cmain) /* Halt. */ pushl $halt_message call EXT_C(printf) loop: hlt jmp loop halt_message: .asciz "Halted." /* Our stack area. */ .comm stack, STACK_SIZE