[U-Boot] Chain loading an u-boot from an u-boot

Helmut Raiger helmut.raiger at hale.at
Wed Apr 9 16:07:46 CEST 2014


On 04/04/2014 11:25 AM, Stefano Babic wrote:
> Hi Helmut,
>
> On 04/04/2014 01:13, Simon Glass wrote:
>
>>> 1) add option to 'go' command, which is hard as it has variable arguments
>>> 2) add another go command
>>> 3) use an environment variable to set the option for 'go'
>>>
>>> Theoretically I could use a u-boot image to encapsulate the second u-boot
>>> and use 'bootm', but I think I'll stumble over the same kind of questions.
>>
>> There is already 'dcache off' but I wonder if something like 'go prepare'
>> would be useful? Another option is that bootm has a prepare state, but it
>> requires an image.
> I agree with Simon. If you have not changed your target, you are using a
> MX31 and what cleanup_linux for arm1136 does is turning off the caches.
> What about if you turn off i-cache and d-cache in einem script before
> the go command ?
>
> Best regards,
> Stefano
>
Hi Stefano,

cleanup_before_linux() also disables interrupts and flushes the cache(s).
Simply turning off the caches did not do the trick.

Using 'go prepare' would be a solution as the 2nd argument should be an 
address (i.e. numeric) in any case.

Thx,
Helmut


--
Scanned by MailScanner.



More information about the U-Boot mailing list