[U-Boot] [PATCH v3 08/29] dm: Allow drivers to be marked 'before relocation'

[Simon Glass]

On 23 July 2014 13:55, Simon Glass <sjg at chromium.org> 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.
>
> To support this, the various dm scanning function now take a 'pre_reloc_only'
> parameter which indicates that only drivers marked pre-reloc should be
> bound.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>

Applied to dm/master.