[U-Boot] [PATCH 2/2] sunxi: Set the AUXCR L2EN bit for sun4i/sun5i in FEL boot mode

Jeroen Hofstee
2014-07-21T20:39:30Z

Hello Ian,

On 21-07-14 22:07, Ian Campbell wrote:
> On Fri, 2014-07-18 at 20:47 +0200, Jeroen Hofstee wrote:
>> Hello Siarhei,
>>
>> On 18-07-14 19:09, Siarhei Siamashka wrote:
>>> This is needed to have feature parity with the normal boot mode,
>>> where the L2EN bit in the CP15 Auxiliary Control Register is set
>>> by the BROM code right from the start.
>>>
>>> If this is not done, the Linux system ends up booted with the L2 cache
>>> disabled.
>>>
>> I don't know a single about the sunxi, but shouldn't linux
>> be patched instead. The commit message seems to indicate
>> it is not an u-boot issue.
> The ACTLR may not be writeable from NS mode so it has to be setup in the
> bootloader before dropping to NS mode.
mmm, I guess there is something wrong with the boot sequence
if the kernel itself can't access raw hw.

> In any case I think these sorts of low level platform specific details
> are the sort of thing which the bootloader probably ought to be setting
> up.

No, u-boot tries not to touch anything it doesn't use and, if anything
disables it after use. Hence, this seems like a kernel bug and nothing
to do with u-boot. They should be independent, iow a kernel should not
rely on u-boot setting thing up, that is a bug.

Regards,
Jeroen