Watchdog timer reset

Hey folks,

Just wondering, does u-boot support periodical reset of watchdog timer ? If not, I suppose I have to disable the watchdog when I enter uboot in interactive mode, and probably enable it when I exit u-boot.

How does people normally do this ?

Just out of curiosity, (assuming u-boot does not do something like above), can we do something similar to below code?

-=-=-=-=-=-=-=-=-=-=-=-=-=-=
signal(SIGALRM, runme);

function runme(void) {
printf("hi\n");
alarm(10);
}
-=-=-=-=-=-=-=-=-=-=-=-=-=-=

Cheers,

Daniel

Yes, of course it does.

If your watchdog i worth it's money it comes up enabled after reset, and you can just disable it once and forever. A watchdog that can be switched of is not worth to be called by that name.

Have a look at the code.

No, we cannot. U-boot is strictly single-tasking and has no notion of signals and the like. Also, your code makes no sense to me.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
I will also, for an appropriate fee, certify that  your  keyboard  is
object-oriented,  and  that  the bits on your hard disk are template-
compatible.            - Jeffrey S. Haemer in <[email protected]>

I'd really appreciate it if you could point me to a file or a function to take a look.

Actually this is really software driven timer we developed on an 8bit micom. So, disable/enable isnt much of bother, but like you said about watchdog, I'm trying to avoid disabling watchdog altogether.

:P sorry for trying an easy way out, but if you happen to know good place to start, dont hesitate (please) :)

Okay, its basically using alarm() to produce SIGALRM every 10 seconds. (assuming alarm() takes second as an argument) And using signal() we are calling runme() function everytime it is woken up by SIGALRM. Natually, runme() will do whatever it needs to do, and sets another alarm before it ends. Not shown in the code, is probably a block read so it keeps the program running.
Hopefully this makes more sense than a code :P

Daniel

watchdog_reset() for example?

Try running something like

	$ cd u-boot
	$ find * -type f | xargs egrep watchdog
or	$ find * -type f | xargs egrep watchdog_reset

See above - this is obviosly hardware dependent, but looking for watchdog_reset() in cpu/*/cpu.c might be helpful...

No, it does not. As mentioned before, there are no signals or tasks or similar in U-Boot. Everything is strictly single-tasking. I'm not sure waht you want, but you can problaby do something like

	for  (;;) {
		/* do something */
		usleep (10 * CFG_HZ);
	}

in C, but I don't understand what that would give you.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Gods don't like people not doing much work. People  who  aren't  busy
all the time might start to _think_.  - Terry Pratchett, _Small Gods_

Thanks. I can see what's going on now. I wasnt really interested about how to reset watchdog itself, but rather continuously calling particular function in set interval. Having looked at how WATCHDOG_RESET() is called, I sort of see it now.

Okay, I got you on U-Boot being single tasking process. And like you said, I wouldnt want to do something like above also :P

Thanks again for putting me on the right track.
Cheers,

Daniel