kolibrios-fun/programs/hd_load/usb_boot/fat32.inc

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fat32_parse_dir:
; in: eax=directory cluster
; out: eax=entry cluster
xor bx, bx
mov di, bx
push eax
call read_cluster
movzx cx, byte [7C0Dh]
shl cx, 4
.scan_cluster:
pop eax
cmp byte [es:di], 0
jz file_not_found
mov si, [esp+2]
push eax
call fat_compare_name
jz .file_found
and di, not 1Fh
add di, 20h
loop .scan_cluster
pop eax
call next_cluster
jnc file_not_found
jc fat32_parse_dir
.file_found:
pop eax
mov si, [esp+2]
mov [cur_obj], si
and di, not 1Fh
mov si, directory_string
mov ax, [es:di+14h]
and ax, 0xFFF
shl eax, 10h
mov ax, [es:di+1Ah]
test eax, eax
mov si, nodata_string
jz find_error_si
ret 2
fat_compare_name:
push cx
mov cx, 9
.scan:
lodsb
cmp al, '.'
jz .ext
cmp al, 0
jz .nameend
cmp al, 'a'
jb .notletter
cmp al, 'z'
ja .notletter
or byte [es:di], 20h
.notletter:
scasb
loopz .scan
.notfound:
inc cx ; to clear ZF flag
pop cx
ret
.ext:
mov al, ' '
dec cx
repz scasb
jnz .notfound
test di, 1
jnz .notfound
mov cx, 4
jmp .scan
.nameend:
mov al, ' '
dec cx
repz scasb
jnz .notfound
test di, 1
jnz .file_found
mov cx, 3
repz scasb
jnz .notfound
.file_found:
xor cx, cx ; to set ZF flag
pop cx
ret