Difference between revisions of "R-Car/Boards/Yocto-Gen3-CommonFAQ/How to use Watchdog timer."

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(How to change timeout-sec)
(How to change timeout-sec)
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Latest revision as of 01:54, 12 November 2020

How to use Watchdog timer.

Start/Reset timer:
ex) using echo:

echo  > /dev/watchdog

End timer:
ex) using echo:

echo "V" > /dev/watchdog

After the timeouts(default: 60 seconds), device reboots.

How to change timeout-sec

Example(Yocto v3.21.0)

bitbake linux-renesas

vim ${WORK}/build/tmp/work-shared/h3ulcb/kernel-source/arch/arm64/boot/dts/renesas/r8a7795-h3ulcb.dts
# add following lines:
&rwdt {
	timeoout-sec = <10>;

cd ${WORK}/build/tmp/work-shared/h3ulcb/kernel-source/

git add arch/arm64/boot/dts/renesas/r8a7795-h3ulcb.dts
git commit -m "arm64: dts: r8a7795-h3ulcb.dts: Add timeout-sec = <10>"
git format-patch -1

cp ./0001-arm64-dts-r8a7795-h3ulcb.dts-Add-timeout-sec-10.patch \

echo -e 'SRC_URI_append = "\\\n file://0001-arm64-dts-r8a7795-h3ulcb.dts-Add-timeout-sec-10.patch\\\n"' \
    > ${WORK}/meta-renesas/meta-rcar-gen3/recipes-kernel/linux/linux-renesas_4.14.bbappend

bitbake linux-renesas

See also: