Diff markup
001 /* Copyright (C) 1999 Free Software Foundatio 001 /* Copyright (C) 1999 Free Software Foundation, Inc.
002 002
003 This program is free software; you can redi 003 This program is free software; you can redistribute it and/or
004 modify it under the terms of the GNU Genera 004 modify it under the terms of the GNU General Public License
005 as published by the Free Software Foundatio 005 as published by the Free Software Foundation; either version 2
006 of the License, or (at your option) any lat 006 of the License, or (at your option) any later version.
007 007
008 This program is distributed in the hope tha 008 This program is distributed in the hope that it will be useful,
009 but WITHOUT ANY WARRANTY; without even the 009 but WITHOUT ANY WARRANTY; without even the implied warranty of
010 MERCHANTABILITY or FITNESS FOR A PARTICULAR 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
011 GNU General Public License for more details 011 GNU General Public License for more details.
012 012
013 You should have received a copy of the GNU 013 You should have received a copy of the GNU General Public License
014 along with this program; if not, write to t 014 along with this program; if not, write to the Free Software
015 Foundation, Inc., 59 Temple Place - Suite 3 015 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
016 USA. 016 USA.
017 */ 017 */
018 018
019 019
020 /* The operating system is booted by Grub, so 020 /* The operating system is booted by Grub, so we almost have nothing
021 to do to boot it. We only have to conform t 021 to do to boot it. We only have to conform to the Multiboot
022 standard, as defined by the Grub documentat 022 standard, as defined by the Grub documentation */
023 023
024 #define ASM 1 024 #define ASM 1
025 /* The multiboot.h header contains a lot of mu 025 /* The multiboot.h header contains a lot of multiboot standard
026 definitions */ 026 definitions */
027 #include "multiboot.h" 027 #include "multiboot.h"
028 028
029 /* The multiboot header itself. It mus 029 /* The multiboot header itself. It must come first. */
030 .section ".multiboot" 030 .section ".multiboot"
031 /* Multiboot header must be aligned on 031 /* Multiboot header must be aligned on a 4-byte boundary */
032 .align 4 032 .align 4
033 multiboot_header: 033 multiboot_header:
034 /* magic= */ .long MULTIBOOT_HEADER_M 034 /* magic= */ .long MULTIBOOT_HEADER_MAGIC
035 /* flags= */ .long MULTIBOOT_HEADER_F 035 /* flags= */ .long MULTIBOOT_HEADER_FLAGS
036 /* checksum= */ .long -(MULTIBOOT_HEADER 036 /* checksum= */ .long -(MULTIBOOT_HEADER_MAGIC \
037 +MULTIBOOT_HEADE 037 +MULTIBOOT_HEADER_FLAGS)
038 /* header_addr= */ .long multiboot_header 038 /* header_addr= */ .long multiboot_header
039 /* load_addr= */ .long __b_load 039 /* load_addr= */ .long __b_load
040 /* load_end_addr=*/ .long __e_load 040 /* load_end_addr=*/ .long __e_load
041 /* bss_end_addr= */ .long __e_kernel 041 /* bss_end_addr= */ .long __e_kernel
042 /* entry_addr= */ .long multiboot_entry 042 /* entry_addr= */ .long multiboot_entry
043 043
044 /* Here is the beginning of the code of our op 044 /* Here is the beginning of the code of our operating system */
045 .text 045 .text
046 046
047 .globl start, _start 047 .globl start, _start
048 start: 048 start:
049 _start: 049 _start:
050 multiboot_entry: 050 multiboot_entry:
051 /* Set up a stack */ 051 /* Set up a stack */
052 movl $(stack + MULTIBOOT_STACK_SIZE), 052 movl $(stack + MULTIBOOT_STACK_SIZE), %ebp
053 movl %ebp, %esp 053 movl %ebp, %esp
054 054
055 /* Set EFLAGS to 0 */ 055 /* Set EFLAGS to 0 */
056 pushl $0 056 pushl $0
057 /* pop stack into the EFLAGS register 057 /* pop stack into the EFLAGS register */
058 popf 058 popf
059 059
060 /* Push the magic and the address on t 060 /* Push the magic and the address on the stack, so that they
061 will be the parameters of the cmain fu 061 will be the parameters of the cmain function */
062 pushl %ebx 062 pushl %ebx
063 pushl %eax 063 pushl %eax
064 064
065 /* Call the cmain function (os.c) */ 065 /* Call the cmain function (os.c) */
066 call EXT_C(sos_main) 066 call EXT_C(sos_main)
067 067
068 /* Should never get there */ 068 /* Should never get there */
069 loop: 069 loop:
070 hlt 070 hlt
071 jmp loop 071 jmp loop
072 072
073 /* Here is the stack */ 073 /* Here is the stack */
074 .section ".init_stack", "aw", @nobits 074 .section ".init_stack", "aw", @nobits
075 .size stack, MULTIBOOT_STACK_SIZE 075 .size stack, MULTIBOOT_STACK_SIZE
076 stack: 076 stack:
077 .space MULTIBOOT_STACK_SIZE 077 .space MULTIBOOT_STACK_SIZE
078 078
079 /* Some data characterizing the stack addresse 079 /* Some data characterizing the stack addresses */
080 .data 080 .data
081 .globl bootstrap_stack_bottom 081 .globl bootstrap_stack_bottom
082 bootstrap_stack_bottom: .long stack 082 bootstrap_stack_bottom: .long stack
083 083
084 .globl bootstrap_stack_size 084 .globl bootstrap_stack_size
085 bootstrap_stack_size: .long MULTIBOOT_STACK_SI 085 bootstrap_stack_size: .long MULTIBOOT_STACK_SIZE