Fix reading FAT32 root dirs that span >1 cluster

[pandora-x-loader.git] / fs / fat / fat.c

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index c6bdb13..44ecb4a 100644 (file)
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -384,7 +384,7 @@ get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
                        newclust = get_fatent(mydata, endclust);
                        if((newclust -1)!=endclust)
                                goto getit;
-                       if (newclust <= 0x0001 || newclust >= 0xfff0) {
+                       if (newclust <= 0x0001 || newclust >= 0xfffff0) {
                                FAT_DPRINT("curclust: 0x%x\n", newclust);
                                FAT_DPRINT("Invalid FAT entry\n");
                                return gotsize;
@@ -419,7 +419,7 @@ getit:
                filesize -= actsize;
                buffer += actsize;
                curclust = get_fatent(mydata, endclust);
-               if (curclust <= 0x0001 || curclust >= 0xfff0) {
+               if (curclust <= 0x0001 || curclust >= 0xfffff0) {
                        FAT_DPRINT("curclust: 0x%x\n", curclust);
                        FAT_ERROR("Invalid FAT entry\n");
                        return gotsize;
@@ -580,7 +580,7 @@ static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
            return retdent;
        }
        curclust = get_fatent (mydata, curclust);
-       if (curclust <= 0x0001 || curclust >= 0xfff0) {
+       if (curclust <= 0x0001 || curclust >= 0xfffff0) {
            FAT_DPRINT ("curclust: 0x%x\n", curclust);
            FAT_ERROR ("Invalid FAT entry\n");
            return NULL;
@@ -679,7 +679,7 @@ do_fat_read(const char *filename, void *buffer, unsigned long maxsize,
     dir_entry *dentptr;
     __u16 prevcksum = 0xffff;
     char *subname = "";
-    int rootdir_size, cursect;
+    int rootdir_size, cursect, curclus;
     int idx, isdir = 0;
     int files = 0, dirs = 0;
     long ret = 0;
@@ -697,6 +697,7 @@ do_fat_read(const char *filename, void *buffer, unsigned long maxsize,
     mydata->fat_sect = bs.reserved;
     cursect = mydata->rootdir_sect
            = mydata->fat_sect + mydata->fatlength * bs.fats;
+    curclus = bs.root_cluster;   // For FAT32 only
     mydata->clust_size = bs.cluster_size;
     if (mydata->fatsize == 32) {
        rootdir_size = mydata->clust_size;
@@ -818,7 +819,16 @@ do_fat_read(const char *filename, void *buffer, unsigned long maxsize,
 
            goto rootdir_done;  /* We got a match */
        }
-       cursect++;
+
+       if (mydata->fatsize != 32)
+          cursect++;
+       else {
+          // FAT32 does not guarantee contiguous root directory
+          curclus = get_fatent (mydata, curclus);
+          cursect = (curclus * mydata->clust_size) + mydata->data_begin;
+
+          FAT_DPRINT ("root clus %d sector %d\n", curclus, cursect);
+       }
     }
   rootdir_done: