[PATCH 4/6] Add filetype and detection for squashfs images

[Sascha Hauer]

From: Enrico Jorns <ejo at pengutronix.de>

This adds `filetype_squashfs` to the list of known filetypes and adds a
detection for squashfs files to file_detect_type(). This currently
matches on the `hsqs` start sequence of an image file.

Additionally, the newly introduced filetype is registered as the type of
the squashfs_driver which allows, for example, to mount squashfs without
the need to specify a type parameter.

This changes enable booting a squashfs with the simple `boot` command
pointing to the location (device) that holds the squashfs.

Note that booting with blspec is limited as the current squashfs driver
is not capable of handling symbolic links.

Signed-off-by: Enrico Jorns <ejo at pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 common/filetype.c      | 4 ++++
 fs/squashfs/squashfs.c | 1 +
 include/filetype.h     | 1 +
 3 files changed, 6 insertions(+)

diff --git a/common/filetype.c b/common/filetype.c
index 4728f87..8d72933 100644
--- a/common/filetype.c
+++ b/common/filetype.c
@@ -40,6 +40,7 @@ static const struct filetype_str filetype_str[] = {
 	[filetype_uimage] = { "U-Boot uImage", "u-boot" },
 	[filetype_ubi] = { "UBI image", "ubi" },
 	[filetype_jffs2] = { "JFFS2 image", "jffs2" },
+	[filetype_squashfs] = { "Squashfs image", "squashfs" },
 	[filetype_gzip] = { "GZIP compressed", "gzip" },
 	[filetype_bzip2] = { "BZIP2 compressed", "bzip2" },
 	[filetype_oftree] = { "open firmware Device Tree flattened Binary", "dtb" },
@@ -278,6 +279,9 @@ enum filetype file_detect_type(const void *_buf, size_t bufsize)
 	if (buf8[0] == 0xfd && buf8[1] == 0x37 && buf8[2] == 0x7a &&
 			buf8[3] == 0x58 && buf8[4] == 0x5a && buf8[5] == 0x00)
 		return filetype_xz_compressed;
+	if (buf8[0] == 'h' && buf8[1] == 's' && buf8[2] == 'q' &&
+			buf8[3] == 's')
+		return filetype_squashfs;
 	if (buf[0] == be32_to_cpu(0xd00dfeed))
 		return filetype_oftree;
 	if (strncmp(buf8, "ANDROID!", 8) == 0)
diff --git a/fs/squashfs/squashfs.c b/fs/squashfs/squashfs.c
index d00dee6..6d04681 100644
--- a/fs/squashfs/squashfs.c
+++ b/fs/squashfs/squashfs.c
@@ -353,6 +353,7 @@ static struct fs_driver_d squashfs_driver = {
 	.readdir	= squashfs_readdir,
 	.closedir	= squashfs_closedir,
 	.stat		= squashfs_stat,
+	.type		= filetype_squashfs,
 	.drv = {
 		.probe = squashfs_probe,
 		.remove = squashfs_remove,
diff --git a/include/filetype.h b/include/filetype.h
index cde73c1..65bd6ef 100644
--- a/include/filetype.h
+++ b/include/filetype.h
@@ -16,6 +16,7 @@ enum filetype {
 	filetype_uimage,
 	filetype_ubi,
 	filetype_jffs2,
+	filetype_squashfs,
 	filetype_gzip,
 	filetype_bzip2,
 	filetype_oftree,
-- 
2.9.3