treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts/bareboximd: add mode argument to open call ...

Newer gcc complain about missing mode argument when a new file is
created. This is an extract of man-pages:

 "The mode argument specifies the file mode bits be applied when
 a new file is created.  This argument must be supplied when
 O_CREAT or O_TMPFILE is specified in flags"

Signed-off-by: Franck Jullien <franck.jullien@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: imd: remove duplicate macro definitions ...

include/scripts/linux/kernel.h included via #include <linux/kernel.h>
later on already defines these three macros. Remove them here to avoid
the warnings about the duplicate macro definition.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

imd: add support for checksum generation/verification ...

Add a new imd type "checksum". This type consists of the CRC32 checksum
of the whole barebox image minus the checksum itself.
The checksum can be written to the imd field with the bareboximd host-tool.
It can be verified with said tool or with "imd" on the target.

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

scripts: removes uses of <asm*/errno.h> in favor of <errno.h> ...

We can't assume <asm/errno.h> to be available on non-Linux hosts.
Furthermore, errno constants values aren't fixed and passing them
to libc perror(3)/strerror (3) would yield wrong results.
Fix this by using the standard <errno.h> header instead.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: bareboximd: remove usage of loff_t ...

loff_t is Linux-specific and unneeded at this place, as sizes are usually
denoted with a size_t. As the signedness of max_size isn't relied on
anywhere, replace it with a size_t.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

stdio: replace fprintf(stderr,...) with eprintf ...

We have a shortcut for fprintf(stderr, so use it. This is done to
be able to remove fprintf in the next step.

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

imd: rename imd_search_validate to imd_get ...

The name is more suitable for what the function does. Also let the
function return a pointer to the imd data found in the buffer.

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

Add support for metadata in barebox images ...

It's often useful to get some information about a barebox image
before starting or flashing it. This patch introduces barebox
Image MetaData (IMD). When enabled a barebox image will contain
a list of tags containing the desired information. We have tags
for:

- the barebox release (2014.07.0-00160-g035de50-dirty)
- the build timestamp (#741 Mon Jul 28 15:08:54 CEST 2014)
- the board model the image is intended for
- the device tree toplevel compatible property

Also there is an additional generic key-value store which stores
parameters for which no dedicated tag exists. In this patch it
is used for the memory size an image supports.

Since there is no fixed offset in a barebox image which can be
used for storing the information, the metadata is stored somewhere
in the image and found by iterating over the image. This works
for most image types, but obviously not for SoC images which are
encoded or encrypted in some way.

There is a 'imd' tool compiled from the same sources for barebox,
for the compile host and for the target, so the metadata information
is available whereever needed.

For device tree boards the model and of_compatible tags are automatically
generated.

Example output of the imd tool for a Phytec phyFLEX image:

build: #889 Wed Jul 30 16:08:54 CEST 2014
release: 2014.07.0-00167-g6b2070d-dirty
parameter: memsize=1024
of_compatible: phytec,imx6x-pbab01 phytec,imx6dl-pfla02 fsl,imx6dl
model: Phytec phyFLEX-i.MX6 Duallite Carrier-Board

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