2023-05-09 04:57:17 +03:00

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/*
This file is part of Fennix Kernel.
Fennix Kernel 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.
Fennix Kernel 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 Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/
.intel_syntax noprefix
.code32
.equ KERNEL_STACK_SIZE, 0x4000 /* 16KB */
.extern DetectCPUID
.extern Detect64Bit
.extern DetectPSE
.extern DetectPAE
.extern multiboot_main
.extern LoadGDT32
.extern BootPageTable
.extern UpdatePageTable
.extern GDT64.Ptr
.extern GDT64.Code
.extern GDT64.Data
.section .bootstrap.data
MB_HeaderMagic:
.quad 0
MB_HeaderInfo:
.quad 0
.section .bootstrap.text
.global Multiboot2_start
Multiboot2_start:
cli
mov [MB_HeaderMagic], eax
mov [MB_HeaderInfo], ebx
call DetectCPUID
cmp eax, 0
je $
call Detect64Bit
cmp eax, 0
je $
call DetectPSE
cmp eax, 0
je $
call DetectPAE
cmp eax, 0
je $
mov ecx, cr4
or ecx, 0x00000010 /* Set PSE in CR4 */
or ecx, 0x00000020 /* Set PAE in CR4 */
mov cr4, ecx
call LoadGDT32
call UpdatePageTable
mov ecx, BootPageTable
mov cr3, ecx
mov ecx, 0xC0000080 /* EFER */
rdmsr
or eax, 0x800 | 0x100 | 0x1 /* Set LME, LMA, SCE */
wrmsr
mov ecx, cr0
or ecx, 0x80000001 /* Set PG and PE in CR0 */
mov cr0, ecx
lgdt [GDT64.Ptr]
jmp GDT64.Code:HigherHalfStart
.extern UpdatePageTable64
.code64
HigherHalfStart:
mov ax, GDT64.Data
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov ss, ax
call UpdatePageTable64
mov rsp, KernelStack + KERNEL_STACK_SIZE
mov rbp, 0
mov rdi, [MB_HeaderMagic]
mov rsi, [MB_HeaderInfo]
push rsi
push rdi
call multiboot_main
.Hang:
hlt
jmp .Hang
.section .bootstrap.bss
.align 16
KernelStack:
.space KERNEL_STACK_SIZE