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https://gitlab.com/sortix/sortix.git
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68 lines
1.7 KiB
ArmAsm
68 lines
1.7 KiB
ArmAsm
/*******************************************************************************
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Copyright(C) Jonas 'Sortie' Termansen 2011, 2014.
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This file is part of Sortix.
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Sortix is free software: you can redistribute it and/or modify it under the
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terms of the GNU General Public License as published by the Free Software
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Foundation, either version 3 of the License, or (at your option) any later
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version.
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Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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details.
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You should have received a copy of the GNU General Public License along with
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Sortix. If not, see <http://www.gnu.org/licenses/>.
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x86/boot.S
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Bootstraps the kernel and passes over control from the boot-loader to the
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kernel main function.
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*******************************************************************************/
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.section .text
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.text 0x100000
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.global _start
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.type _start, @function
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_start:
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jmp prepare_kernel_execution
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# Align 32 bits boundary.
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.align 4
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# Multiboot header.
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multiboot_header:
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# Magic.
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.long 0x1BADB002
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# Flags.
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.long 0x00000003
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# Checksum.
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.long -(0x1BADB002 + 0x00000003)
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prepare_kernel_execution:
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# Enable the floating point unit.
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mov %eax, 0x100000
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mov %cr0, %eax
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and $0xFFFD, %ax
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or $0x10, %ax
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mov %eax, %cr0
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fninit
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# Enable Streaming SIMD Extensions.
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mov %cr0, %eax
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and $0xFFFB, %ax
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or $0x2, %ax
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mov %eax, %cr0
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mov %cr4, %eax
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or $0x600, %eax
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mov %eax, %cr4
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mov 0x100000, %eax
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# Store a copy of the initialial floating point registers.
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fxsave fpu_initialized_regs
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jmp beginkernel
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