tl;dr: dd will silently truncate the output if reading from special
files (e.g. sysfs attributes) with a too large bs parameter.
This problem was exposed on some RouterBOARD ipq40xx devices which use a
caldata payload which is larger than PAGE_SIZE, contrary to all other
currently supported RouterBOARD devices: the caldata would fail to
properly load with the current scripts.
Background: dd doesn't seem to correctly handle read() results that
return less than requested data. sysfs attributes have a kernel exchange
buffer which is at most PAGE_SIZE big, so only 1 page can be read() at a
time. In this case, if bs is larger than PAGE_SIZE, dd will silently
truncate blocks to PAGE_SIZE. With the current scripts using bs=<size>
count=1, the data is truncated to PAGE_SIZE as soon as the requested
<size> exceeds this value.
This commit works around this problem by using `cat` in the caldata
routines that can read from a file (routines that read from mtd devices
are untouched). cat correctly handles partial read requests. The output
is then piped to dd with the same parameters as before, to ensure that
the resulting file remains exactly the same.
This is a simple workaround, the downside is that it uses a pipe and one
more executable, and therefore has a larger memory footprint and is
slower. This is deemed acceptable considering these routines are only
used at boot time.
Tested-by: Robert Marko <robimarko@gmail.com>
Signed-off-by: Thibaut VARÈNE <hacks@slashdirt.org>
This will enable platforms to extract caldata to an arbitrary file,
or patch mac in an abitrary file.
Signed-off-by: Thibaut VARÈNE <hacks@slashdirt.org>
"[[" is a bash extension for test. As the ash-implementation is
not fully compatible we drop its usage.
Also change to "=" for simple test, which is sufficient. (see d6ac8ca76c)
Signed-off-by: Sven Roederer <devel-sven@geroedel.de>
[split patch, removed shebang]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
While all ath10k eeproms have a checksum field, so far two
functions for patching ath10k MAC address have been present (and
been used).
This merges code to provide a single function ath10k_patch_mac
in caldata.sh, having its name in accordance with ath9k functions.
By doing so, correct MAC patching for current and future ath10k
devices should be ensured.
This patch adds checksum adjustments for several targets on
ath79 and lantiq.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
This unifies MAC address patch functions and moves them to a
common script. While those were implemented differently for
different targets, they all seem to do the same. The number of
different variants is significantly reduced by this patch.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
This moves the almost identical calibration data extraction
functions present multiple times in several targets to a single
library file /lib/functions/caldata.sh.
Functions are renamed with more generic names to merge different
variants that only differ in their names.
Most of the targets used find_mtd_chardev, while some used
find_mtd_part inside the extraction code. To merge them, the more
abundant version with find_mtd_chardev is used in the common code.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
[rebase on latest master; add mpc85xx]
Signed-off-by: David Bauer <mail@david-bauer.net>
