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--- cramfs-1.1/mkcramfs.c.orig 2005-04-13 05:55:57.000000000 -0600
+++ cramfs-1.1/mkcramfs.c 2005-04-13 16:19:57.000000000 -0600
@@ -117,6 +117,7 @@
static int opt_squash = 0;
static char *opt_image = NULL;
static char *opt_name = NULL;
+static int swap_endian = 0;
static int warn_dev, warn_gid, warn_namelen, warn_skip, warn_size, warn_uid;
static const char *const memory_exhausted = "memory exhausted";
@@ -155,6 +156,7 @@
" -i file insert a file image into the filesystem (requires >= 2.4.0)\n"
" -n name set name of cramfs filesystem\n"
" -p pad by %d bytes for boot code\n"
+ " -r reverse endian-ness of filesystem\n"
" -s sort directory entries (old option, ignored)\n"
" -v be more verbose\n"
" -z make explicit holes (requires >= 2.3.39)\n"
@@ -504,6 +506,50 @@
return totalsize;
}
+/* routines to swap endianness/bitfields in inode/superblock block data */
+static void fix_inode(struct cramfs_inode *inode)
+{
+#define wswap(x) (((x)>>24) | (((x)>>8)&0xff00) | (((x)&0xff00)<<8) | (((x)&0xff)<<24))
+ /* attempt #2 */
+ inode->mode = (inode->mode >> 8) | ((inode->mode&0xff)<<8);
+ inode->uid = (inode->uid >> 8) | ((inode->uid&0xff)<<8);
+ inode->size = (inode->size >> 16) | (inode->size&0xff00) |
+ ((inode->size&0xff)<<16);
+ ((u32*)inode)[2] = wswap(inode->offset | (inode->namelen<<26));
+}
+
+static void fix_offset(struct cramfs_inode *inode, u32 offset)
+{
+ u32 tmp = wswap(((u32*)inode)[2]);
+ ((u32*)inode)[2] = wswap((offset >> 2) | (tmp&0xfc000000));
+}
+
+static void fix_block_pointer(u32 *p)
+{
+ *p = wswap(*p);
+}
+
+static void fix_super(struct cramfs_super *super)
+{
+ u32 *p = (u32*)super;
+
+ /* fix superblock fields */
+ p[0] = wswap(p[0]); /* magic */
+ p[1] = wswap(p[1]); /* size */
+ p[2] = wswap(p[2]); /* flags */
+ p[3] = wswap(p[3]); /* future */
+
+ /* fix filesystem info fields */
+ p = (u32*)&super->fsid;
+ p[0] = wswap(p[0]); /* crc */
+ p[1] = wswap(p[1]); /* edition */
+ p[2] = wswap(p[2]); /* blocks */
+ p[3] = wswap(p[3]); /* files */
+
+ fix_inode(&super->root);
+#undef wswap
+}
+
/* Returns sizeof(struct cramfs_super), which includes the root inode. */
static unsigned int write_superblock(struct entry *root, char *base, int size)
{
@@ -539,6 +585,7 @@
super->root.gid = root->gid;
super->root.size = root->size;
super->root.offset = offset >> 2;
+ if (swap_endian) fix_super(super);
return offset;
}
@@ -553,7 +600,10 @@
if (offset >= (1 << (2 + CRAMFS_OFFSET_WIDTH))) {
error_msg_and_die("filesystem too big");
}
- inode->offset = (offset >> 2);
+ if (swap_endian)
+ fix_offset(inode, offset);
+ else
+ inode->offset = (offset >> 2);
}
/*
@@ -638,6 +688,7 @@
stack_entries++;
}
entry = entry->next;
+ if (swap_endian) fix_inode(inode);
}
/*
@@ -734,6 +785,7 @@
}
*(u32 *) (base + offset) = curr;
+ if (swap_endian) fix_block_pointer((u32*)(base + offset));
offset += 4;
} while (size);
@@ -1146,7 +1198,7 @@
progname = argv[0];
/* command line options */
- while ((c = getopt(argc, argv, "hEe:i:n:psvzD:q")) != EOF) {
+ while ((c = getopt(argc, argv, "hEe:i:n:prsvzD:q")) != EOF) {
switch (c) {
case 'h':
usage(MKFS_OK);
@@ -1174,6 +1226,10 @@
opt_pad = PAD_SIZE;
fslen_ub += PAD_SIZE;
break;
+ case 'r':
+ swap_endian = 1;
+ printf("Swapping filesystem endian-ness\n");
+ break;
case 's':
/* old option, ignored */
break;
|
