[U-Boot] [PATCH 1/6] SPL: Add NOR flash booting support

[Stefan Roese]

On 08/23/2012 05:07 PM, Tom Rini wrote:
> On 08/23/2012 01:12 AM, Stefan Roese wrote:
>> SPL NOR flash booting support is quite simple. Only copying of the
>> images is needed.
>>
>> On MPC5xxx we need to make sure to only use the standard memcpy()
>> implementation and not the MPC5xxx specific one. As the MPC5xxx
>> version has some complexity which is not needed for this SPL
>> booting.
> 
> I assume there's good reason to use SPL on NOR here?  Is a near-future
> goal to do SPL-boots-Linux and thus the desire for a very small loader?

Yes. As explained in the cover-letter, the board port using this SPL NOR
support (MPC5200 based) mainly uses this SPL framework to speed up
booting into Linux. Less code loaded from NOR, zero relocation (on this
PPC port at least), etc.

My first quick tests show a boot to Linux speedup by approx. 0.5 seconds
compared to the good-old U-Boot -> Linux booting. So it definitely makes
sense in time-critical bootup situation.

Thanks,
Stefan