[meta-xilinx] u-boot SPL boot fail with CONFIG_HW_WATCHDOG

[Michal Simek]

On 03/26/2014 10:26 AM, Mike Looijmans wrote:
> For a custom board with an external GPIO controlled watchdog, I tried adding watchdog support to u-boot. (using master-next from u-boot-xlnx)
> 
> The watchdog support works (I'm using a LED for now until the real hardware arrives), I just defined CONFIG_HW_WATCHDOG and added a reset routine that bitbangs the GPIO registers which should feed the watchdog. 
I can see the LED blink, so the GPIO routines appear to work well.
> 
> However, this causes the board to fail to boot the kernel.
> 
> If I define CONFIG_HW_WATCHDOG and leave the hw_watchdog_*() methods empty, so that there SHOULD be no effect, the kernel will not boot and the system hangs immediately after "Starting kernel...". 
Removing the define from the board config makes that problem go away. If I call the GPIO routines from the board code in u-boot, the kernel still boots fine too.

> 
> The zynq has no support for any WATCHDOG yet, so I have no idea what could cause this behaviour.
> 
> I'm looking for a possible cause. Any ideas?
> 
> 
> Related question #1: Would you be interested in a patch that adds GPIO support for the Zynq to u-boot?
> 
> Related question #2: Would you be interested in a patch that adds watchdog support for the built-in Zynq watchdog to u-boot?

I am interested in any code related to zynq/microblaze which make sense.
Ad 1) I looked at it in past on it but haven't finish it
Ad 2) Definitely that will be useful to have like we have it for microblaze soft core watchdog.

Thanks,
Michal