Hi Wolfgang,
Dear Stefan Roese,
In message 201005201355.01964.sr@denx.de you wrote:
Also I would like to determine in u-boot if a reset was caused by the watchdog timer using the TSR WRS field. If it was reset by the watchdog we will boot into a failsafe partition to protect against system update errors.
Has anyone done something like this?
Such a detection is not implemented for PPC4xx. Not sure if it's implemented for any other architecture.
I think lwmon5 performs such checking; eventually this is buryied somewhere in the POST code.
Well, at least I know that for mpc5121 we read the reser status register at boot and copy it to global data (arch/powerpc/cpu/mpc512x/cpu_init.c:64). The value is also output in the U-Boot prompt (arch/powerpc/cpu/mpc512x/cpu.c:68) which is a nice thing IMHO.
Checking a "git grep reset_status" one can see that something similar is done for other PowerPC cpus as well, so I'd suggest reusing this method for ppc4xx and providing a mechanism to access this information from a script.
Cheers Detlev