blob: 97f6fb710202d981ecfb3eccf646cc45479d77f3 [file] [log] [blame]
/*
* (C) Copyright 2002
* Stäubli Faverges - <www.staubli.com>
* Pierre AUBERT p.aubert@staubli.com
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <config.h>
#include <malloc.h>
#include "dos.h"
#include "fdos.h"
static int cache_sect;
static unsigned char cache [SZ_STD_SECTOR];
#define min(x,y) ((x)<(y)?(x):(y))
static int descend (Slot_t *parent,
Fs_t *fs,
char *path);
/*-----------------------------------------------------------------------------
* init_subdir --
*-----------------------------------------------------------------------------
*/
void init_subdir (void)
{
cache_sect = -1;
}
/*-----------------------------------------------------------------------------
* basename --
*-----------------------------------------------------------------------------
*/
char *basename (char *name)
{
register char *cptr;
if (!name || !*name) {
return ("");
}
for (cptr= name; *cptr++; );
while (--cptr >= name) {
if (*cptr == '/') {
return (cptr + 1);
}
}
return(name);
}
/*-----------------------------------------------------------------------------
* root_map --
*-----------------------------------------------------------------------------
*/
static int root_map (Fs_t *fs, Slot_t *file, int where, int *len)
{
*len = min (*len, fs -> dir_len * SZ_STD_SECTOR - where);
if (*len < 0 ) {
*len = 0;
return (-1);
}
return fs -> dir_start * SZ_STD_SECTOR + where;
}
/*-----------------------------------------------------------------------------
* normal_map --
*-----------------------------------------------------------------------------
*/
static int normal_map (Fs_t *fs, Slot_t *file, int where, int *len)
{
int offset;
int NrClu;
unsigned short RelCluNr;
unsigned short CurCluNr;
unsigned short NewCluNr;
unsigned short AbsCluNr;
int clus_size;
clus_size = fs -> cluster_size * SZ_STD_SECTOR;
offset = where % clus_size;
*len = min (*len, file -> FileSize - where);
if (*len < 0 ) {
*len = 0;
return (0);
}
if (file -> FirstAbsCluNr < 2){
*len = 0;
return (0);
}
RelCluNr = where / clus_size;
if (RelCluNr >= file -> PreviousRelCluNr){
CurCluNr = file -> PreviousRelCluNr;
AbsCluNr = file -> PreviousAbsCluNr;
} else {
CurCluNr = 0;
AbsCluNr = file -> FirstAbsCluNr;
}
NrClu = (offset + *len - 1) / clus_size;
while (CurCluNr <= RelCluNr + NrClu) {
if (CurCluNr == RelCluNr){
/* we have reached the beginning of our zone. Save
* coordinates */
file -> PreviousRelCluNr = RelCluNr;
file -> PreviousAbsCluNr = AbsCluNr;
}
NewCluNr = fat_decode (fs, AbsCluNr);
if (NewCluNr == 1 || NewCluNr == 0) {
PRINTF("Fat problem while decoding %d %x\n",
AbsCluNr, NewCluNr);
return (-1);
}
if (CurCluNr == RelCluNr + NrClu) {
break;
}
if (CurCluNr < RelCluNr && NewCluNr == FAT12_END) {
*len = 0;
return 0;
}
if (CurCluNr >= RelCluNr && NewCluNr != AbsCluNr + 1)
break;
CurCluNr++;
AbsCluNr = NewCluNr;
}
*len = min (*len, (1 + CurCluNr - RelCluNr) * clus_size - offset);
return (((file -> PreviousAbsCluNr - 2) * fs -> cluster_size +
fs -> dir_start + fs -> dir_len) *
SZ_STD_SECTOR + offset);
}
/*-----------------------------------------------------------------------------
* open_subdir -- open the subdir containing the file
*-----------------------------------------------------------------------------
*/
int open_subdir (File_t *desc)
{
char *pathname;
char *tmp, *s, *path;
char terminator;
if ((pathname = (char *)malloc (MAX_PATH)) == NULL) {
return (-1);
}
strcpy (pathname, desc -> name);
/* Suppress file name */
tmp = basename (pathname);
*tmp = '\0';
/* root directory init */
desc -> subdir.FirstAbsCluNr = 0;
desc -> subdir.FileSize = -1;
desc -> subdir.map = root_map;
desc -> subdir.dir.attr = ATTR_DIRECTORY;
tmp = pathname;
for (s = tmp; ; ++s) {
if (*s == '/' || *s == '\0') {
path = tmp;
terminator = *s;
*s = '\0';
if (s != tmp && strcmp (path,".")) {
if (descend (&desc -> subdir, desc -> fs, path) < 0) {
free (pathname);
return (-1);
}
}
if (terminator == 0) {
break;
}
tmp = s + 1;
}
}
free (pathname);
return (0);
}
/*-----------------------------------------------------------------------------
* descend --
*-----------------------------------------------------------------------------
*/
static int descend (Slot_t *parent,
Fs_t *fs,
char *path)
{
int entry;
Slot_t SubDir;
if(path[0] == '\0' || strcmp (path, ".") == 0) {
return (0);
}
entry = 0;
if (vfat_lookup (parent,
fs,
&(SubDir.dir),
&entry,
0,
path,
ACCEPT_DIR | SINGLE | DO_OPEN,
0,
&SubDir) == 0) {
*parent = SubDir;
return (0);
}
if (strcmp(path, "..") == 0) {
parent -> FileSize = -1;
parent -> FirstAbsCluNr = 0;
parent -> map = root_map;
return (0);
}
return (-1);
}
/*-----------------------------------------------------------------------------
* open_file --
*-----------------------------------------------------------------------------
*/
int open_file (Slot_t *file, Directory_t *dir)
{
int first;
unsigned long size;
first = __le16_to_cpu (dir -> start);
if(first == 0 &&
(dir -> attr & ATTR_DIRECTORY) != 0) {
file -> FirstAbsCluNr = 0;
file -> FileSize = -1;
file -> map = root_map;
return (0);
}
if ((dir -> attr & ATTR_DIRECTORY) != 0) {
size = (1UL << 31) - 1;
}
else {
size = __le32_to_cpu (dir -> size);
}
file -> map = normal_map;
file -> FirstAbsCluNr = first;
file -> PreviousRelCluNr = 0xffff;
file -> FileSize = size;
return (0);
}
/*-----------------------------------------------------------------------------
* read_file --
*-----------------------------------------------------------------------------
*/
int read_file (Fs_t *fs,
Slot_t *file,
char *buf,
int where,
int len)
{
int pos;
int read, nb, sect, offset;
pos = file -> map (fs, file, where, &len);
if (pos < 0) {
return -1;
}
if (len == 0) {
return (0);
}
/* Compute sector number */
sect = pos / SZ_STD_SECTOR;
offset = pos % SZ_STD_SECTOR;
read = 0;
if (offset) {
/* Read doesn't start at the sector beginning. We need to use our */
/* cache */
if (sect != cache_sect) {
if (dev_read (cache, sect, 1) < 0) {
return (-1);
}
cache_sect = sect;
}
nb = min (len, SZ_STD_SECTOR - offset);
memcpy (buf, cache + offset, nb);
read += nb;
len -= nb;
sect += 1;
}
if (len > SZ_STD_SECTOR) {
nb = (len - 1) / SZ_STD_SECTOR;
if (dev_read (buf + read, sect, nb) < 0) {
return ((read) ? read : -1);
}
/* update sector position */
sect += nb;
/* Update byte position */
nb *= SZ_STD_SECTOR;
read += nb;
len -= nb;
}
if (len) {
if (sect != cache_sect) {
if (dev_read (cache, sect, 1) < 0) {
return ((read) ? read : -1);
cache_sect = -1;
}
cache_sect = sect;
}
memcpy (buf + read, cache, len);
read += len;
}
return (read);
}