cramfs.patch

sm86xx rootfs来源包括补丁（ GPL ）的

+	unsigned long mode, unsigned long rdev, struct entry *root, loff_t *fslen_ub)
+{
+	char *name, *path, *full;
+	struct entry *curr, *parent, *entry, *prev;
+	
+	full = xstrdup(full_path);
+	path = xstrdup(dirname(full));
+	name = full_path + strlen(path) + 1;
+	free(full);
+	if (strcmp(path, "/") == 0) {
+		parent = root;
+		name = full_path + 1;
+	} else {
+		if (!(parent = find_filesystem_entry(root, path+1, S_IFDIR)))
+			error_msg_and_die("%s/%s: could not find parent\n", path, name);
+	}
+	if ((entry = find_filesystem_entry(parent, name, (mode & S_IFMT)))) {
+		/* its there, just modify permissions */
+		entry->mode = mode;
+		entry->uid = uid;
+		entry->gid = gid;
+	} else { /* make a new entry */
+	
+		/* code partially replicated from parse_directory() */
+		size_t namelen;
+		if (S_ISREG(mode)) {
+			error_msg_and_die("%s: regular file from device_table file must exist on disk!", full_path);
+		}
+
+		namelen = strlen(name);
+		if (namelen > MAX_INPUT_NAMELEN) {
+			error_msg_and_die(
+				"Very long (%u bytes) filename `%s' found.\n"
+				" Please increase MAX_INPUT_NAMELEN in mkcramfs.c and recompile.  Exiting.\n",
+				namelen, name);
+		}
+		entry = xcalloc(1, sizeof(struct entry));
+		entry->name = xstrdup(name);
+		/* truncate multi-byte UTF-8 filenames on character boundary */
+		if (namelen > CRAMFS_MAXPATHLEN) {
+			namelen = CRAMFS_MAXPATHLEN;
+			warn_namelen = 1;
+			/* the first lost byte must not be a trail byte */
+			while ((entry->name[namelen] & 0xc0) == 0x80) {
+				namelen--;
+				/* are we reasonably certain it was UTF-8 ? */
+				if (entry->name[namelen] < 0x80 || !namelen) {
+					error_msg_and_die("cannot truncate filenames not encoded in UTF-8");
+				}
+			}
+			entry->name[namelen] = '\0';
+		}
+		entry->mode = mode;
+		entry->uid = uid;
+		entry->gid = gid;
+		entry->size = 0;
+		if (S_ISBLK(mode) || S_ISCHR(mode)) {
+			entry->size = rdev;
+			if (entry->size & -(1<<CRAMFS_SIZE_WIDTH))
+				warn_dev = 1;
+		}
+		
+		/* ok, now we have to backup and correct the size of all the entries above us */
+		*fslen_ub += sizeof(struct cramfs_inode) + ((namelen + 3) & ~3);
+		parent->size += sizeof(struct cramfs_inode) + ((namelen + 3) & ~3);
+
+		/* alright, time to link us in */
+		curr = parent->child;
+		prev = NULL;
+		while (curr && strcmp(name, curr->name) > 0) {
+			prev = curr;
+			curr = curr->next;
+		}
+		if (!prev) parent->child = entry;
+		else prev->next = entry;
+		entry->next = curr;
+		entry->child = NULL;
+	}
+	if (entry->uid >= 1 << CRAMFS_UID_WIDTH)
+		warn_uid = 1;
+	if (entry->gid >= 1 << CRAMFS_GID_WIDTH) {
+		/* TODO: We ought to replace with a default
+		   gid instead of truncating; otherwise there
+		   are security problems.  Maybe mode should
+		   be &= ~070.  Same goes for uid once Linux
+		   supports >16-bit uids. */
+		warn_gid = 1;
+	}
+	free(path);
+}
+
+/* the GNU C library has a wonderful scanf("%as", string) which will
+ allocate the string with the right size, good to avoid buffer overruns. 
+ the following macros use it if available or use a hacky workaround...
+ */
+
+#ifdef __GNUC__
+#define SCANF_PREFIX "a"
+#define SCANF_STRING(s) (&s)
+#define GETCWD_SIZE 0
+#else
+#define SCANF_PREFIX "511"
+#define SCANF_STRING(s) (s = xmalloc(512))
+#define GETCWD_SIZE -1
+inline int snprintf(char *str, size_t n, const char *fmt, ...)
+{
+	int ret;
+	va_list ap;
+
+	va_start(ap, fmt);
+	ret = vsprintf(str, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+#endif
+
+/*  device table entries take the form of:
+    <path>	<type> <mode>	<uid>	<gid>	<major>	<minor>	<start>	<inc>	<count>
+    /dev/mem     c    640       0       0         1       1       0     0         -
+
+    type can be one of: 
+	f	A regular file
+	d	Directory
+	c	Character special device file
+	b	Block special device file
+	p	Fifo (named pipe)
+
+    I don't bother with symlinks (permissions are irrelevant), hard
+    links (special cases of regular files), or sockets (why bother).
+
+    Regular files must exist in the target root directory.  If a char,
+    block, fifo, or directory does not exist, it will be created.
+*/
+
+static int interpret_table_entry(char *line, struct entry *root, loff_t *fslen_ub)
+{
+	char type, *name = NULL;
+	unsigned long mode = 0755, uid = 0, gid = 0, major = 0, minor = 0;
+	unsigned long start = 0, increment = 1, count = 0;
+
+	if (sscanf (line, "%" SCANF_PREFIX "s %c %lo %lu %lu %lu %lu %lu %lu %lu",
+		 SCANF_STRING(name), &type, &mode, &uid, &gid, &major, &minor,
+		 &start, &increment, &count) < 0) 
+	{
+		return 1;
+	}
+
+	if (!strcmp(name, "/")) {
+		error_msg_and_die("Device table entries require absolute paths");
+	}
+
+	switch (type) {
+	case 'd':
+		mode |= S_IFDIR;
+		modify_entry(name, uid, gid, mode, 0, root, fslen_ub);
+		break;
+	case 'f':
+		mode |= S_IFREG;
+		modify_entry(name, uid, gid, mode, 0, root, fslen_ub);
+		break;
+	case 'p':
+		mode |= S_IFIFO;
+		modify_entry(name, uid, gid, mode, 0, root, fslen_ub);
+		break;
+	case 'c':
+	case 'b':
+		mode |= (type == 'c') ? S_IFCHR : S_IFBLK;
+		if (count > 0) {
+			char *buf;
+			unsigned long i;
+			dev_t rdev;
+
+			for (i = start; i < count; i++) {
+				asprintf(&buf, "%s%lu", name, i);
+				rdev = makedev(major, minor + (i * increment - start));
+				modify_entry(buf, uid, gid, mode, rdev, root, fslen_ub);
+				free(buf);
+			}
+		} else {
+			dev_t rdev = makedev(major, minor);
+			modify_entry(name, uid, gid, mode, rdev, root, fslen_ub);
+		}
+		break;
+	default:
+		error_msg_and_die("Unsupported file type");
+	}
+	free(name);
+	return 0;
+}
+
+static int parse_device_table(FILE *file, struct entry *root, loff_t *fslen_ub)
+{
+	char *line;
+	int status = 0;
+	size_t length = 0;
+
+	/* Turn off squash, since we must ensure that values
+	 * entered via the device table are not squashed */
+	opt_squash = 0;
+
+	/* Looks ok so far.  The general plan now is to read in one
+	 * line at a time, check for leading comment delimiters ('#'),
+	 * then try and parse the line as a device table.  If we fail
+	 * to parse things, try and help the poor fool to fix their
+	 * device table with a useful error msg... */
+	line = NULL;
+	while (getline(&line, &length, file) != -1) {
+		/* First trim off any whitespace */
+		int len = strlen(line);
+
+		/* trim trailing whitespace */
+		while (len > 0 && isspace(line[len - 1]))
+			line[--len] = '\0';
+		/* trim leading whitespace */
+		memmove(line, &line[strspn(line, " \n\r\t\v")], len);
+
+		/* How long are we after trimming? */
+		len = strlen(line);
+
+		/* If this is NOT a comment line, try to interpret it */
+		if (len && *line != '#') {
+			if (interpret_table_entry(line, root, fslen_ub))
+				status = 1;
+		}
+
+		free(line);
+		line = NULL;
+	}
+	free(line);
+	fclose(file);
+
+	return status;
+}
+
+void traverse(struct entry *entry, int depth)
+{
+	struct entry *curr = entry;
+	int i;
+
+	while (curr) {
+		for (i = 0; i < depth; i++) putchar(' ');
+		printf("%s: size=%d mode=%d same=%p\n",
+			(curr->name)? (char*)curr->name : "/", 
+			curr->size, curr->mode, curr->same);
+		if (curr->child) traverse(curr->child, depth + 4);
+		curr = curr->next;
+	}
+}
+
+static void free_filesystem_entry(struct entry *dir)
+{
+	struct entry *e = dir, *last;
+
+	if (S_ISDIR(dir->mode)) {
+		e = dir->child;
+	}
+	while (e) {
+		if (e->name)
+			free(e->name);
+		if (e->path)
+			free(e->path);
+		if (e->uncompressed)
+			free(e->uncompressed);
+		last = e;
+		if (e->child) {
+			free_filesystem_entry(e);
+		}
+		e = e->next;
+		free(last);
+	}
+}
+
+
+/*
+ * Usage:
+ *
+ *      mkcramfs directory-name outfile
+ *
+ * where "directory-name" is simply the root of the directory
+ * tree that we want to generate a compressed filesystem out
+ * of.
+ */
 int main(int argc, char **argv)
 {
 	struct stat st;		/* used twice... */
@@ -692,6 +1138,7 @@
 	u32 crc;
 	int c;			/* for getopt */
 	char *ep;		/* for strtoul */
+	FILE *devtable = NULL;
 
 	total_blocks = 0;
 
@@ -699,7 +1146,7 @@
 		progname = argv[0];
 
 	/* command line options */
-	while ((c = getopt(argc, argv, "hEe:i:n:psvz")) != EOF) {
+	while ((c = getopt(argc, argv, "hEe:i:n:psvzD:q")) != EOF) {
 		switch (c) {
 		case 'h':
 			usage(MKFS_OK);
@@ -715,7 +1162,7 @@
 		case 'i':
 			opt_image = optarg;
 			if (lstat(opt_image, &st) < 0) {
-				die(MKFS_ERROR, 1, "lstat failed: %s", opt_image);
+				error_msg_and_die("lstat failed: %s", opt_image);
 			}
 			image_length = st.st_size; /* may be padded later */
 			fslen_ub += (image_length + 3); /* 3 is for padding */
@@ -736,6 +1183,16 @@
 		case 'z':
 			opt_holes = 1;
 			break;
+		case 'q':
+			opt_squash = 1;
+			break;
+		case 'D':
+			devtable = xfopen(optarg, "r");
+			if (fstat(fileno(devtable), &st) < 0)
+				perror_msg_and_die(optarg);
+			if (st.st_size < 10)
+				error_msg_and_die("%s: not a proper device table file\n", optarg);
+			break;
 		}
 	}
 
@@ -745,25 +1202,23 @@
 	outfile = argv[optind + 1];
 
 	if (stat(dirname, &st) < 0) {
-		die(MKFS_USAGE, 1, "stat failed: %s", dirname);
-	}
-	fd = open(outfile, O_WRONLY | O_CREAT | O_TRUNC, 0666);
-	if (fd < 0) {
-		die(MKFS_USAGE, 1, "open failed: %s", outfile);
+		error_msg_and_die("stat failed: %s", dirname);
 	}
+	fd = xopen(outfile, O_WRONLY | O_CREAT | O_TRUNC, 0666);
 
-	root_entry = calloc(1, sizeof(struct entry));
-	if (!root_entry) {
-		die(MKFS_ERROR, 1, "calloc failed");
-	}
+	root_entry = xcalloc(1, sizeof(struct entry));
 	root_entry->mode = st.st_mode;
 	root_entry->uid = st.st_uid;
 	root_entry->gid = st.st_gid;
 
 	root_entry->size = parse_directory(root_entry, dirname, &root_entry->child, &fslen_ub);
 
+	if (devtable) {
+		parse_device_table(devtable, root_entry, &fslen_ub);
+	}
+
 	/* always allocate a multiple of blksize bytes because that's
-	   what we're going to write later on */
+           what we're going to write later on */
 	fslen_ub = ((fslen_ub - 1) | (blksize - 1)) + 1;
 
 	if (fslen_ub > MAXFSLEN) {
@@ -790,7 +1245,7 @@
 	rom_image = mmap(NULL, fslen_ub?fslen_ub:1, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
 	if (rom_image == MAP_FAILED) {
-		die(MKFS_ERROR, 1, "mmap failed");
+		error_msg_and_die("mmap failed");
 	}
 
 	/* Skip the first opt_pad bytes for boot loader code */
@@ -807,6 +1262,7 @@
 	}
 
 	offset = write_directory_structure(root_entry->child, rom_image, offset);
+	if (opt_verbose)
 	printf("Directory data: %d bytes\n", offset);
 
 	offset = write_data(root_entry, rom_image, offset);
@@ -814,30 +1270,38 @@
 	/* We always write a multiple of blksize bytes, so that
 	   losetup works. */
 	offset = ((offset - 1) | (blksize - 1)) + 1;
+	if (opt_verbose)
 	printf("Everything: %d kilobytes\n", offset >> 10);
 
 	/* Write the superblock now that we can fill in all of the fields. */
 	write_superblock(root_entry, rom_image+opt_pad, offset);
+	if (opt_verbose)
 	printf("Super block: %d bytes\n", sizeof(struct cramfs_super));
 
 	/* Put the checksum in. */
 	crc = crc32(0L, Z_NULL, 0);
 	crc = crc32(crc, (rom_image+opt_pad), (offset-opt_pad));
 	((struct cramfs_super *) (rom_image+opt_pad))->fsid.crc = crc;
+	if (opt_verbose)
 	printf("CRC: %x\n", crc);
 
 	/* Check to make sure we allocated enough space. */
 	if (fslen_ub < offset) {
-		die(MKFS_ERROR, 0, "not enough space allocated for ROM image (%Ld allocated, %d used)", fslen_ub, offset);
+		error_msg_and_die("not enough space allocated for ROM "
+			"image (%Ld allocated, %d used)", fslen_ub, offset);
 	}
 
 	written = write(fd, rom_image, offset);
 	if (written < 0) {
-		die(MKFS_ERROR, 1, "write failed");
+		error_msg_and_die("write failed");
 	}
 	if (offset != written) {
-		die(MKFS_ERROR, 0, "ROM image write failed (wrote %d of %d bytes)", written, offset);
+		error_msg_and_die("ROM image write failed (wrote %d of %d bytes)", written, offset);
 	}
+	
+	/* Free up memory */
+	free_filesystem_entry(root_entry);
+	free(root_entry);
 
 	/* (These warnings used to come at the start, but they scroll off the
 	   screen too quickly.) */