R: [U-Boot-Users] PATCH: Introducing CONFIG_BOARD_PRE_RESET

[Paolo Broggini]

> -----Messaggio originale-----
> Da: u-boot-users-admin at lists.sourceforge.net
> [mailto:u-boot-users-admin at lists.sourceforge.net]Per conto di Steven
> Scholz
> Inviato: martedi, 26. ottobre 2004 10:32
> Cc: u-boot-users
> Oggetto: Re: [U-Boot-Users] PATCH: Introducing CONFIG_BOARD_PRE_RESET
> 
> 
> Wolfgang Denk wrote:
> 
> > In message <417DF771.5010904 at imc-berlin.de> you wrote:
> > 
> >>Well, it's a bug in the CPU. If the LCDC DMA is running, the 
> cpu won't reboot 
> >>with a simple "mov pc, r0".
> > 
> > 
> > Ummm... you don't call this a "reset", do you?
> 
> Well that's what is done (work) for most ARM920T... Execeptions are
> 
> #ifdef CONFIG_S3C2400
>          bl      disable_interrupts
> # ifdef CONFIG_TRAB
>          bl      disable_vfd
> # endif
> ...
> 
> BTW cominh to think about it: Does "bl disable_vfd" by any chance 
> disable video 
> controller for CONFIG_TRAB !?!? ;-)
> 
> > In your case, I think you really want to  implement  a  _real_  reset
> > function  that  takes the CPU back into it's virgin state. Is there a
> > watchdog on this hardware?
> 
> Sure. That means you have board _and_ cpu specific reset code!
> Some want to toggle a GPIO pin. Some want to use a cpu watchdog...
> So should we move the reset code out of cpu/arm920t/start.S into 
> the brand new 
> cpu/arm920t/$(SOC)/reset.{S.c} !?

This would be a good step towards clean up the clobbered start.s !!!
-P.Broggini