[U-Boot] [PATCH 6/9] ARM: Implement CONFIG_SKIP_LOWLEVEL_INIT for arm926ej-s

[Albert ARIBAUD]

Hi Wolfgang et al.,

(replying both to 5/9 and 6/9 here)

Le 25/04/2011 01:55, Wolfgang Denk a écrit :

> This is an inconsistency between architectures which I dislike.

Then these two config options could be defined for other architectures 
as well.

> Also, what in case we should want to skip only cpu_init_crit and not
> lowlevel_init? If we need to handle these separately, then we need 2
> CONFIG options.

Agreed this complete separation could be useful in case U-Boot is not 
the code executed on startup, and this startup code does the CPU 
initialization but leaves the rest to U-Boot for commodity.

> How can the SDRAM be initialized when the CPU is not?

Debugging sessions come to mind, where the debugger resets the target 
and initializes SDRAM to load the target code. I've also seen cases on 
multiple-core ICs where an ARM core starts with SDRAM access already 
working, but U-Boot was not involved.

The idea is that during board bring-up, rather than have people try and 
neutralize some code in assembly language startup files, they just 
temporarily define the configuration options CONFIG_SKIP_* in their 
board's config header file (and, for those boards that have an IPL of 
some sort before U-Boot, they keep the relevant CONFIG_SKIP_* there once 
debugged).

> Best regards,
>
> Wolfgang Denk

Amicalement,
-- 
Albert.