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sortix--sortix/kernel/x86/boot.S
2014-03-01 14:37:40 +01:00

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1.6 KiB
ArmAsm

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011.
This file is part of Sortix.
Sortix 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.
Sortix 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
Sortix. If not, see <http://www.gnu.org/licenses/>.
x86/boot.S
Bootstraps the kernel and passes over control from the boot-loader to the
kernel main function.
*******************************************************************************/
.section .text
.text 0x100000
.global _start
.type _start, @function
_start:
jmp prepare_kernel_execution
# Align 32 bits boundary.
.align 4
# Multiboot header.
multiboot_header:
# Magic.
.long 0x1BADB002
# Flags.
.long 0x00000003
# Checksum.
.long -(0x1BADB002 + 0x00000003)
prepare_kernel_execution:
# Enable the floating point unit.
mov %eax, 0x100000
mov %cr0, %eax
and $0xFFFD, %ax
or $0x10, %ax
mov %eax, %cr0
fninit
# Enable Streaming SIMD Extensions.
mov %cr0, %eax
and $0xFFFB, %ax
or $0x2, %ax
mov %eax, %cr0
mov %cr4, %eax
or $0x600, %eax
mov %eax, %cr4
mov 0x100000, %eax
jmp beginkernel