[U-Boot] [PATCH v2 01/11] ARM: fix relocation on ARM926EJS

[Marek Vasut]

Dear Tom Rini,

> On Sun, Sep 16, 2012 at 05:36:47PM +0200, Marek Vasut wrote:
> > Dear Jos? Miguel Gon?alves,
> > 
> > > On 09/16/2012 11:06 AM, Marek Vasut wrote:
> > > > Dear Jos? Miguel Gon?alves,
> > > > 
> > > >> On 09/15/2012 07:03 PM, Marek Vasut wrote:
> > > >>> Dear Jos? Miguel Gon?alves,
> > > >>> 
> > > >>>> Jumping to board_init_r is not performed due to a bug on address
> > > >>>> computation.
> > > >>> 
> > > >>> Is your CONFIG_SYS_TEXT_BASE configured correctly? I don't detect
> > > >>> any misbehavior on my arm926 boards.
> > > >> 
> > > >> Maybe because you are not using it to build an SPL?
> > > > 
> > > > I do ... and I use CONFIG_SPL_TEXT_BASE properly .
> > > > 
> > > >> Please check the same chunk of code in other start.S for arm1176 and
> > > >> armv7. They have the same code that I put for arm926ejs.
> > > > 
> > > > Please wait and please first explain what is the issue.
> > > 
> > > The issue is what I've explained in the patch comments.
> > 
> > "Jumping to board_init_r is not performed due to a bug on address
> > computation."
> > 
> > Ok, I don't know how to replicate the bug from this comment or what
> > effects it causes or ... well, anything. So please, try to be more
> > elaborate in your patch description next time. Anyway ..
> > 
> > > Without this
> > > change the code never reaches board_init_r in the SPL and I think I
> > > have all the configurations correctly set.
> > 
> > I wonder why you'd ever want to reach board_init_r in the SPL. SPL is
> > there only to load the real U-Boot from whatever media, so you usually
> > use either NAND SPL
> 
> Here's a good point for me to jump in, I think.  There's two things to
> understand:
> - In the current in-tree SPL implementations the code flow is
>   board_init_f calls relocate_code() to clear the BSS _and_ get our jump
>   to board_init_r.  It does not actually relocate the running U-Boot,
>   just clears the BSS.  board_init_r is what calls the things to load
>   and boot the next stage (U-Boot or Linux).
> 
> - In my series this has been changed slightly to be board_init_f calls
>   memset and then board_init_r directly.  So this patch should not be
>   needed once rebased on that series.

Do we need to do all the relocation in assembler code btw? Can it not be moved 
into C code and made generic across all platforms (module the stack adjustment 
and a few minor things) ?

Best regards,
Marek Vasut