Subversion Repositories Kolibri OS

;;  23.04.2006 LFN read - diamond                                  ;;

    ret

; \begin{diamond}

hd_find_lfn:

; in: esi->name

; out: CF=1 - file not found

;      else CF=0 and edi->direntry

	pusha

	sub	esp, 262*2	; allocate space for LFN

	mov	ebp, esp

	mov	eax, [ROOT_CLUSTER]	; start from root

.mainloop:

.new_cluster:

	mov	[cluster_tmp], eax

	mov	[fat16_root], 0

	cmp	eax, [LAST_CLUSTER]

	ja	.notfound

	cmp	eax, 2

	jae	.data_cluster

	cmp	[fat_type], 16

	jnz	.notfound

	mov	eax, [ROOT_START]

	mov	ecx, [ROOT_SECTORS]

	mov	[fat16_root], 1

	jmp	.new_sector

.data_cluster:

	dec	eax

	dec	eax

	mov	ecx, [SECTORS_PER_CLUSTER]

	mul	ecx

	add	eax, [DATA_START]

.new_sector:

	mov	ebx, buffer

	call	hd_read

	mov	edi, ebx

	add	ebx, 512

	push	eax

.l1:

	call	fat_get_name

	jc	.l2

	call	fat_compare_name

	jz	.found

.l2:

	add	edi, 0x20

	cmp	edi, ebx

	jb	.l1

	pop	eax

	inc	eax

	loop	.new_sector

	cmp	[fat16_root], 0

	jnz	.notfound

	mov	eax, [cluster_tmp]

	call	get_FAT

	cmp	eax, 2

	jb	.notfound

	cmp	eax, [fatRESERVED]

	jb	.new_cluster

.notfound:

	add	esp, 262*2

	popa

	stc

	ret

.found:

	pop	eax

; if this is LFN entry, advance to true entry

	cmp	byte [edi+11], 0xF

	jnz	.entryfound

	add	edi, 0x20

	cmp	edi, ebx

	jb	.entryfound

	inc	eax

	dec	ecx

	jnz	.read_entry

	cmp	[fat16_root], 0

	jnz	.notfound

	mov	eax, [cluster_tmp]

	call	get_FAT

	cmp	eax, 2

	jb	.notfound

	cmp	eax, [fatRESERVED]

	jae	.notfound

	dec	eax

	dec	eax

	mul	[SECTORS_PER_CLUSTER]

	add	eax, [DATA_START]

.read_entry:

	mov	ebx, [buffer]

	call	hd_read

	mov	edi, ebx

.entryfound:

	cmp	byte [esi], 0

	jz	.done

	test	byte [edi+11], 10h	; is a directory?

	jz	.notfound

	mov	eax, [edi+20-2]

	mov	ax, [edi+26]

	jmp	.mainloop

.done:

	add	esp, 262*2+4	; CF=0

	push	edi

	popad

	ret

;----------------------------------------------------------------

;

;  fs_HdRead - LFN variant for reading hard disk

;

;  esi  points to filename

;  ebx  pointer to 64-bit number = first wanted byte, 0+

;       may be ebx=0 - start from first byte

;  ecx  number of bytes to read, 0+

;  edx  mem location to return data

;

;  ret ebx = size or 0xffffffff file not found

;      eax = 0 ok read or other = errormsg

;

;--------------------------------------------------------------

fs_HdRead:

	cmp	[fat_type], 0

	jnz	@f

	or	ebx, -1

	mov	eax, ERROR_UNKNOWN_FS

	ret

@@:

	push	edi

	cmp	byte [esi], 0

	jnz	@f

.noaccess:

	pop	edi

	or	ebx, -1

	mov	eax, ERROR_ACCESS_DENIED

	ret

@@:

	call	hd_find_lfn

	jnc	.found

	pop	edi

	or	ebx, -1

	mov	eax, ERROR_FILE_NOT_FOUND

	ret

.found:

	test	byte [edi+11], 0x10	; do not allow read directories

	jnz	.noaccess

	test	ebx, ebx

	jz	.l1

	cmp	dword [ebx+4], 0

	jz	@f

	mov	ebx, [edi+28]

.reteof:

	mov	eax, 6

	pop	edi

	ret

@@:

	mov	ebx, [ebx]

.l1:

	push	dword [edi+28]		; file size

	mov	eax, [edi+20-2]

	mov	ax, [edi+26]

	push	ecx edx

	push	dword [edi+28]

; now eax=cluster, ebx=position, ecx=count, edx=buffer for data

.new_cluster:

	jecxz	.new_sector

	test	eax, eax

	jz	.eof

	cmp	eax, [fatRESERVED]

	jae	.eof

	mov	[cluster_tmp], eax

	dec	eax

	dec	eax

	mov	edi, [SECTORS_PER_CLUSTER]

	imul	eax, edi

	add	eax, [DATA_START]

.new_sector:

	test	ecx, ecx

	jz	.done

	sub	ebx, 512

	jae	.skip

	add	ebx, 512

	jnz	.force_buf

	cmp	ecx, 512

	jb	.force_buf

	cmp	dword [esp], 512

	jb	.force_buf

; we may read directly to given buffer

	push	ebx

	mov	ebx, edx

	call	hd_read

	pop	ebx

	add	edx, 512

	sub	ecx, 512

	sub	dword [esp], 512

	jmp	.skip

.force_buf:

; we must read sector to temporary buffer and then copy it to destination

	push	eax ebx

	mov	ebx, buffer

	call	hd_read

	mov	eax, ebx

	pop	ebx

	add	eax, ebx

	push	ecx

	add	ecx, ebx

	cmp	ecx, 512

	jbe	@f

	mov	ecx, 512

@@:

	sub	ecx, ebx

	cmp	ecx, [esp+8]

	jbe	@f

	mov	ecx, [esp+8]

@@:

	mov	ebx, edx

	call	memmove

	add	edx, ecx

	sub	[esp], ecx

	sub	[esp+8], ecx

	pop	ecx

	pop	eax

	xor	ebx, ebx

	cmp	[esp], ebx

	jnz	.skip

	jecxz	.done

	jmp	.eof

.skip:

	inc	eax

	dec	edi

	jnz	.new_sector

	mov	eax, [cluster_tmp]

	call	get_FAT

	jmp	.new_cluster

.done:

	pop	ebx edx ecx ebx edi

	xor	eax, eax

	ret

.eof:

	pop	ebx edx ecx ebx