88fad3c56e
Mainly adding support in write_cell() to use logical character indexes vs direct memory offsets
47 lines
1.2 KiB
NASM
47 lines
1.2 KiB
NASM
; since we have no stack we have to create one for the OS
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global loader
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MAGIC_NUMBER equ 0x1BADB002
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FLAGS equ 0x0
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CHECKSUM equ -MAGIC_NUMBER
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; size in bytes of stack
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KERNEL_STACK_SIZE equ 4096
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; external labels(cdecl) calling convention
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extern yote
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section .bss
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align 4 ; aligning to bytes for x86(32-bit) reasons
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; because this is the first thing we actually do (virual)address 0x00000000 will
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; contain 4KB of memory for our stack
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kernel_stack:
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resb KERNEL_STACK_SIZE ; reserver bytes instruction
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; point to what will be bottom of stack
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; which will grow down towards (virtual)address 0x00000000
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mov esp, kernel_stack + KERNEL_STACK_SIZE
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section .text
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; align all instructions to 4 byte boundary by the x86 instruction set law
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align 4
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; dropping our magic and other things into memory
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dd MAGIC_NUMBER
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dd FLAGS
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dd CHECKSUM
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loader:
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call yote
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.loop:
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jmp .loop
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; section for our kernel stack
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KERNEL_STACK_SIZE equ 4096
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section .bss
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align 4 ; aligned to 4 bytes for performance
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kernel_stack:
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; (res)erve (b)ytes x
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resb KERNEL_STACK_SIZE ; 4k of stack size in mem
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; now we setup the stack pointer for our kernel
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mov esp, kernel_stack + KERNEL_STACK_SIZE
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