we're using the PicoMod7A with kernel 3.3.7 and u-boot 2012.07.
On three different of about 20 devices (until now) we had the problem, that after a long time (2-3 months) of running without problems the kernel got broken. The devices are crashing and aren't booting any more. When I connect the debug port (COM3) I see:
and nothing more happens. It seems the kernel is copied into RAM, is executed but contains invalid code so nothing happens. After I reload the kernel and FFS from SD-Card everything is working correctly again.
In the bootargs the kernel is write protected "3m(Kernel)ro,-TargetFS". So I hope it will be impossible to cause overwriting parts of the kernel from an application running in the buildroot FFS.
Can you give us any advice why this is happening? Where can we start isolating the problem?
Thanks in advance