fs/uimagefs: Use is_tftp_fs() and cache_file() to ease TFTP workaround ...

We have helper functions now to ease file caching when a file
is on TFTP. Use them.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

uimage: fix: add can_lseek_backward and use in uimage_open ...

Since commit ce0cc7fe we support forward seek on tftpfs. This feature
breaks the condition to check rather we open an uimage over tftp. Since
backward seeking is the problem here, we add the function
can_lseek_backward and check for it instead of the simple lseek.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

string: Fix (v)asprintf prototypes ...

Our asprintf and vasprintf have different prototypes than the glibc
functions. This causes trouble when we want to share barebox code
with userspace code. Change the prototypes for (v)asprintf to match
the glibc prototypes. Since the current (v)asprintf are convenient
to use change the existing functions to b(v)asprintf.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

include: move crc specific stuff to crc.h ...

We have a crc.h, so move our crc function prototypes there to further
cleanup common.h.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: rename inode member of struct filep to priv ...

Because that's what it is. 'inode' will become confusing
once we support real inodes.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

move file helper functions to separate file ...

We have our file helper functions in several places. Move them
all to lib/libfile.c.
With this we no longer have file helpers in fs/fs.c which contains
the core fs functions and no functions in lib/libbb.c which are
not from busybox.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/fs' ...

Conflicts:
	fs/Kconfig
	fs/Makefile

fs: add uimagefs ...

this will provide the image data and information via file

 # ls -l /tmp/
-rwxrwxrwx          3 arch
-rwxrwxrwx         12 compression
-rwxrwxrwx         16 name
-rwxrwxrwx          5 os
-rwxrwxrwx         24 time
-rwxrwxrwx         12 type
-rwxrwxrwx         10 load_addr
-rwxrwxrwx         10 entry_point
-rwxrwxrwx    2199875 data0
-rwxrwxrwx    2199875 data
-rwxrwxrwx         10 data.crc

if it's multi image

 # ls -l /tmp-multi/
-rwxrwxrwx          3 arch
-rwxrwxrwx         12 compression
-rwxrwxrwx         16 name
-rwxrwxrwx          5 os
-rwxrwxrwx         24 time
-rwxrwxrwx         16 type
-rwxrwxrwx         10 load_addr
-rwxrwxrwx         10 entry_point
-rwxrwxrwx       1292 data0
-rwxrwxrwx        983 data1
-rwxrwxrwx       2287 data
-rwxrwxrwx         10 data.crc

you can get the image header via an ioctl on any file
UIMAGEFS_METADATA

if you want to check the crc do

 # crc32 -f /tmp-multi/data -V /tmp-multi/data.crc
CRC32 for /tmp-multi/data 0x00000000 ... 0x000008ee ==> 0x88d5a0db

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>