[U-Boot] [PATCH v2 08/29] dm: Allow drivers to be marked 'before relocation'

[Simon Glass]

Hi Marek,

On 10 July 2014 17:29, Marek Vasut <marex at denx.de> wrote:
> On Wednesday, July 09, 2014 at 05:37:58 AM, Simon Glass wrote:
>> Driver model currently only operates after relocation is complete. In this
>> state U-Boot typically has a small amount of memory available. In adding
>> support for driver model prior to relocation we must try to use as little
>> memory as possible.
>>
>> In addition, on some machines the memory has not be inited and/or the CPU
>> is not running at full speed or the data cache is off. These can reduce
>> execution performance, so the less initialisation that is done before
>> relocation the better.
>>
>> An immediately-obvious improvement is to only initialise drivers which are
>> actually going to be used before relocation. On many boards the only such
>> driver is a serial UART, so this provides a very large potential benefit.
>>
>> Allow drivers to mark themselves as 'pre-reloc' which means that they will
>> be initialised prior to relocation. This can be done either with a driver
>> flag or with a 'dm,pre-reloc' device tree property.
>
> I think we should start marking those DT props something like 'u-boot,dm-pre-
> reloc' instead . The same way as Linux marks it's own linux-specific DT props.

Yes good idea, I'll fix that.

Regards,
Simon