fs/fat/file.c

   1 /*
   2  * file.c
   3  *
   4  * Mini "VFS" by Marcus Sundberg
   5  *
   6  * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
   7  * 2003-03-10 - kharris@nexus-tech.net - ported to uboot
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 #include <common.h>
  13 #include <config.h>
  14 #include <malloc.h>
  15 #include <fat.h>
  16 #include <linux/stat.h>
  17 #include <linux/time.h>
  18
  19 /* Supported filesystems */
  20 static const struct filesystem filesystems[] = {
  21         { file_fat_detectfs,  file_fat_ls,  file_fat_read,  "FAT" },
  22 };
  23 #define NUM_FILESYS     (sizeof(filesystems)/sizeof(struct filesystem))
  24
  25 /* The filesystem which was last detected */
  26 static int current_filesystem = FSTYPE_NONE;
  27
  28 /* The current working directory */
  29 #define CWD_LEN         511
  30 char file_cwd[CWD_LEN+1] = "/";
  31
  32 const char *
  33 file_getfsname(int idx)
  34 {
  35         if (idx < 0 || idx >= NUM_FILESYS)
  36                 return NULL;
  37
  38         return filesystems[idx].name;
  39 }
  40
  41 static void
  42 pathcpy(char *dest, const char *src)
  43 {
  44         char *origdest = dest;
  45
  46         do {
  47                 if (dest-file_cwd >= CWD_LEN) {
  48                         *dest = '\0';
  49                         return;
  50                 }
  51                 *(dest) = *(src);
  52                 if (*src == '\0') {
  53                         if (dest-- != origdest && ISDIRDELIM(*dest)) {
  54                                 *dest = '\0';
  55                         }
  56                         return;
  57                 }
  58                 ++dest;
  59
  60                 if (ISDIRDELIM(*src))
  61                         while (ISDIRDELIM(*src)) src++;
  62                 else
  63                         src++;
  64         } while (1);
  65 }
  66
  67 int
  68 file_cd(const char *path)
  69 {
  70         if (ISDIRDELIM(*path)) {
  71                 while (ISDIRDELIM(*path)) path++;
  72                 strncpy(file_cwd+1, path, CWD_LEN-1);
  73         } else {
  74                 const char *origpath = path;
  75                 char *tmpstr = file_cwd;
  76                 int back = 0;
  77
  78                 while (*tmpstr != '\0') tmpstr++;
  79                 do {
  80                         tmpstr--;
  81                 } while (ISDIRDELIM(*tmpstr));
  82
  83                 while (*path == '.') {
  84                         path++;
  85                         while (*path == '.') {
  86                                 path++;
  87                                 back++;
  88                         }
  89                         if (*path != '\0' && !ISDIRDELIM(*path)) {
  90                                 path = origpath;
  91                                 back = 0;
  92                                 break;
  93                         }
  94                         while (ISDIRDELIM(*path)) path++;
  95                         origpath = path;
  96                 }
  97
  98                 while (back--) {
  99                         /* Strip off path component */
 100                         while (!ISDIRDELIM(*tmpstr)) {
 101                                 tmpstr--;
 102                         }
 103                         if (tmpstr == file_cwd) {
 104                                 /* Incremented again right after the loop. */
 105                                 tmpstr--;
 106                                 break;
 107                         }
 108                         /* Skip delimiters */
 109                         while (ISDIRDELIM(*tmpstr)) tmpstr--;
 110                 }
 111                 tmpstr++;
 112                 if (*path == '\0') {
 113                         if (tmpstr == file_cwd) {
 114                                 *tmpstr = '/';
 115                                 tmpstr++;
 116                         }
 117                         *tmpstr = '\0';
 118                         return 0;
 119                 }
 120                 *tmpstr = '/';
 121                 pathcpy(tmpstr+1, path);
 122         }
 123
 124         return 0;
 125 }
 126
 127 int
 128 file_detectfs(void)
 129 {
 130         int i;
 131
 132         current_filesystem = FSTYPE_NONE;
 133
 134         for (i = 0; i < NUM_FILESYS; i++) {
 135                 if (filesystems[i].detect() == 0) {
 136                         strcpy(file_cwd, "/");
 137                         current_filesystem = i;
 138                         break;
 139                 }
 140         }
 141
 142         return current_filesystem;
 143 }
 144
 145 int
 146 file_ls(const char *dir)
 147 {
 148         char fullpath[1024];
 149         const char *arg;
 150
 151         if (current_filesystem == FSTYPE_NONE) {
 152                 printf("Can't list files without a filesystem!\n");
 153                 return -1;
 154         }
 155
 156         if (ISDIRDELIM(*dir)) {
 157                 arg = dir;
 158         } else {
 159                 sprintf(fullpath, "%s/%s", file_cwd, dir);
 160                 arg = fullpath;
 161         }
 162         return filesystems[current_filesystem].ls(arg);
 163 }
 164
 165 int file_read(const char *filename, void *buffer, int maxsize)
 166 {
 167         char fullpath[1024];
 168         const char *arg;
 169
 170         if (current_filesystem == FSTYPE_NONE) {
 171                 printf("Can't load file without a filesystem!\n");
 172                 return -1;
 173         }
 174
 175         if (ISDIRDELIM(*filename)) {
 176                 arg = filename;
 177         } else {
 178                 sprintf(fullpath, "%s/%s", file_cwd, filename);
 179                 arg = fullpath;
 180         }
 181
 182         return filesystems[current_filesystem].read(arg, buffer, maxsize);
 183 }