[U-Boot] [PATCH] Add ability for arch code to make changes before we boot

Kumar Gala galak at kernel.crashing.org
Wed Aug 26 01:05:37 CEST 2009


On Aug 15, 2009, at 9:24 AM, Jean-Christophe PLAGNIOL-VILLARD wrote:

> On 15:45 Fri 14 Aug     , Kumar Gala wrote:
>>
>> On Aug 14, 2009, at 3:13 PM, Jean-Christophe PLAGNIOL-VILLARD wrote:
>>
>>> On 14:00 Fri 14 Aug     , Kumar Gala wrote:
>>>> Added a arch_preboot() function that cpu specific code can
>>>> implement to
>>>> allow for various modifications to the state of the machine
>>>> right before
>>>> we boot.  This can be useful to setup register state to a specific
>>>> configuration.
>>>>
>>>> Signed-off-by: Kumar Gala <galak at kernel.crashing.org>
>>>> ---
>>>> common/cmd_bootm.c |   10 ++++++++++
>>>> 1 files changed, 10 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
>>>> index 86c8122..766889a 100644
>>>> --- a/common/cmd_bootm.c
>>>> +++ b/common/cmd_bootm.c
>>>> @@ -166,6 +166,13 @@ void __arch_lmb_reserve(struct lmb *lmb)
>>>> }
>>>> void arch_lmb_reserve(struct lmb *lmb) __attribute__((weak,
>>>> alias("__arch_lmb_reserve")));
>>>>
>>>> +/* Allow for arch specific config before we boot */
>>>> +void __arch_preboot(void)
>>>> +{
>>>> +	/* please define platform specific arch_preboot() */
>>>> +}
>>>> +void arch_preboot(void) __attribute__((weak,
>>>> alias("__arch_preboot")));
>>>> +
>>> why not a section so you will be able to have multiple callback so
>>> it can be
>>> arch or soc or board too in any combination
>>
>> Because the use I have for it is a simple single case at this point.
>>
>> If and when we need more complexity we can add it.
> we have already it
> as example the usb drivers that need to be stop before start an os
> I forget some but I'm sure to have seen oher

We already handle USB in the bootm code.  I don't see any reason to go  
add a bunch of code for the one case we handle.

- k


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