ReC98/th05/formats/bb_load.asm

33 lines
691 B
NASM

; void* pascal near bb_load(const char far *fn);
public BB_LOAD
bb_load proc near
push si
call hmem_allocbyte pascal, BB_SIZE
mov _bb_load_seg, ax
mov bx, sp
mov si, ds
mov ax, 3D00h
lds dx, ss:[bx+4]
int 21h ; DOS - 2+ - OPEN DISK FILE WITH HANDLE
; DS:DX -> ASCIZ filename
; AL = access mode
; 0 - read
mov bx, ax
mov ds, si
mov ds, _bb_load_seg
mov cx, BB_SIZE
xor dx, dx
mov ah, 3Fh
int 21h ; DOS - 2+ - READ FROM FILE WITH HANDLE
; BX = file handle, CX = number of bytes to read
; DS:DX -> buffer
mov ah, 3Eh
int 21h ; DOS - 2+ - CLOSE A FILE WITH HANDLE
; BX = file handle
mov ds, si
pop si
mov ax, _bb_load_seg
retn 4
bb_load endp
nop