On Feb 24, 2011, at 13:41, Wolfgang Denk wrote:
> In message <e379de2e-dded-45ad-b44b-8006d883f...@boeing.com> you wrote:
>>
>> Perhaps the default should instead be something like this?
>>
>> __attribute__((__weak__)) int arch_reset(void)
>> {
>> while(1);
>> }
>
> No. Please don;t implement something that does not do what it is
> supposed to do. Rather make the problem obvious.
>
>> Having a default might make it easier to do the initial standup of a new CPU
>> type (less code to write initially), but you wouldn't get any obvious errors
>> about the fact that you are missing functionality.
>
> That's a fundamentally broken approach. You know how people work:
> they start, they have something running without too blatant error
> messages, they leave it as is and go on to the next task.
>
> I rather see a clear unresolved external reference error instead of a
> bad defualt that doesn't work.
Ok, I'm working on an updated patch.
There are a few CPU architectures like the 74xx_7xx which have worrying
comments like these:
/* no generic way to do board reset. simply call soft_reset. */
It basically just disables caching and performs a jump to the CPU reset vector.
Several boards already have overrides of various sorts to use board-specific
reset vectors; from looking at commit logs and configuration for the boards
based on the 74xx and 7xx I'm not convinced that reset function has ever been
tested on some of them.
I would almost be willing to argue that if that kind of "soft reset" is a
desirable feature then U-Boot should support it separately via a
"kexec()"-style interface.
Anyways, I should be sending out a new patch here shortly.
Cheers,
Kyle Moffett
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
