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Began work on new bootloader (KBOOT)

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Tom-on
2024-12-26 23:08:06 +01:00
parent bad812554d
commit 12b07a9f70
8 changed files with 246 additions and 870 deletions
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boot/gdt.s
+29
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; Global Descriptor Table
gdt:
.null_desc: ; Just zeros, no clue why it even exists
dq 0
.code_desc: ; 32-bit code
dw 0xffff ; Limit (low 16-bits)
dw 0x0000 ; Base (low 16 bits)
db 0x00 ; Base (mid 8 bits)
db 0b10011011 ; Access flags
db 0b11001111 ; Low 4 bits - Granularity, High 4 bits - Limit (high 4 bits)
db 0x00 ; Base (high 8 bits)
.data_desc: ; 32-bit data
dw 0xffff ; Limit (low 16-bits)
dw 0x0000 ; Base (low 16 bits)
db 0x00 ; Base (mid 8 bits)
db 0b10010011 ; Access flags
db 0b11001111 ; Low 4 bits - Granularity, High 4 bits - Limit (high 4 bits)
db 0x00 ; Base (high 8 bits)
.end:
; GDT Pointer
gdtp:
dw gdt.end - gdt - 1 ; Size
dd gdt ; Pointer
; Segments
code_seg equ gdt.code_desc - gdt
data_seg equ gdt.data_desc - gdt