62 lines
1.8 KiB
ArmAsm
62 lines
1.8 KiB
ArmAsm
/**
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* Boot section of rockOS
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* Copyright (C) 2022 Furkan Mudanyali
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, _either version 3 of the License, or
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* (at your option) any later version.
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*
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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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*
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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, see <https://www.gnu.org/licenses/>.
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*/
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# Declare constants for multiboot header
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.set ALIGN, 1<<0 # align loaded modules on page boundaries
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.set MEMINFO, 1<<1 # provide memory map
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.set FLAGS, ALIGN | MEMINFO # multiboot flag field
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.set MAGIC, 0x1BADB002 # magic number for bootloader to find header
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.set CHECKSUM, -(MAGIC + FLAGS) # checksum of above
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# Declare header in multiboot standard
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.section .multiboot
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.align 4
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.long MAGIC
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.long FLAGS
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.long CHECKSUM
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# Reserve a stack for initial thread
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.section .bss
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.align 16
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stack_bottom:
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.skip 32768 # 32 KiB
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stack_top:
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# kernel entry point
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.section .text
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.global _start
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.type _start, @function
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_start:
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push %eax
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push %ebx
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call bootloader_init
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cli
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call gdt_init # initialize the GDT
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movl $stack_top, %esp
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call terminal_initialize
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call idt_init # initialize the IDT
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call PIC_remap
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sti
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call paging_init
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call kernel_main # transfer control to main kernel
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# Hang if kernel_main unexpectedly returns
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1: hlt
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jmp 1b
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.size _start, . - _start
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