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42 lines (31 loc) · 849 Bytes
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boot_sect_stack.asm
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42 lines (31 loc) · 849 Bytes
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mov ah, 0x0e ; tty mode
mov bp, 0x8000 ; this is an address far away from 0x7c00 so that we don't get overwritten
mov sp, bp ; if the stack is empty then sp points to bp
push 'A'
push 'B'
push 'C'
; to show how the stack grows downwards
mov al, [0x7ffe] ; 0x8000 - 2
int 0x10
; however, don't try to access [0x8000] now, because it won't work
; you can only access the stack top so, at this point, only 0x7ffe (look above)
mov al, [0x8000]
int 0x10
; recover our characters using the standard procedure: 'pop'
; We can only pop full words so we need an auxiliary register to manipulate
; the lower byte
pop bx
mov al, bl
int 0x10 ; prints C
pop bx
mov al, bl
int 0x10 ; prints B
pop bx
mov al, bl
int 0x10 ; prints A
; data that has been pop'd from the stack is garbage now
mov al, [0x8000]
int 0x10
jmp $
times 510-($-$$) db 0
dw 0xaa55