86 lines
2.5 KiB
ArmAsm
86 lines
2.5 KiB
ArmAsm
/* Copyright (C) 1999 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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USA.
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*/
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/* The operating system is booted by Grub, so we almost have nothing
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to do to boot it. We only have to conform to the Multiboot
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standard, as defined by the Grub documentation */
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#define ASM 1
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/* The multiboot.h header contains a lot of multiboot standard
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definitions */
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#include "multiboot.h"
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/* The multiboot header itself. It must come first. */
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.section ".multiboot"
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/* Multiboot header must be aligned on a 4-byte boundary */
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.align 4
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multiboot_header:
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/* magic= */ .long MULTIBOOT_HEADER_MAGIC
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/* flags= */ .long MULTIBOOT_HEADER_FLAGS
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/* checksum= */ .long -(MULTIBOOT_HEADER_MAGIC \
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+MULTIBOOT_HEADER_FLAGS)
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/* header_addr= */ .long multiboot_header
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/* load_addr= */ .long __b_load
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/* load_end_addr=*/ .long __e_load
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/* bss_end_addr= */ .long __e_kernel
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/* entry_addr= */ .long multiboot_entry
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/* Here is the beginning of the code of our operating system */
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.text
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.globl start, _start
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start:
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_start:
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multiboot_entry:
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/* Set up a stack */
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movl $(stack + MULTIBOOT_STACK_SIZE), %ebp
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movl %ebp, %esp
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/* Set EFLAGS to 0 */
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pushl $0
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/* pop stack into the EFLAGS register */
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popf
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/* Push the magic and the address on the stack, so that they
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will be the parameters of the cmain function */
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pushl %ebx
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pushl %eax
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/* Call the cmain function (os.c) */
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call EXT_C(sos_main)
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/* Should never get there */
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loop:
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hlt
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jmp loop
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/* Here is the stack */
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.section ".init_stack", "aw", @nobits
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.size stack, MULTIBOOT_STACK_SIZE
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stack:
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.space MULTIBOOT_STACK_SIZE
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/* Some data characterizing the stack addresses */
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.data
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.globl bootstrap_stack_bottom
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bootstrap_stack_bottom: .long stack
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.globl bootstrap_stack_size
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bootstrap_stack_size: .long MULTIBOOT_STACK_SIZE
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