[U-Boot] [PATCH v4] Fix board init code to use a valid C runtime environment

[Alexey Brodkin]

Hi Albert,

On Mon, 2015-11-16 at 14:34 +0100, Albert ARIBAUD wrote:
> Hello Alexey,
> 
> On Mon, 16 Nov 2015 13:12:15 +0000, Alexey Brodkin
> <Alexey.Brodkin at synopsys.com> wrote:
> > Hi Albert,

> > >  
> > > -	/* Allocate and zero GD, update SP */
> > > -	mov	%r0, %sp
> > > -	bl	board_init_f_mem
> > > -
> > > +	/* Get reserved area size, update SP and FP */
> > > +	bl	board_init_f_get_reserve_size
> > >  	/* Update stack- and frame-pointers */
> > 
> > I think we don't need to mention SP/FP update in comments twice here.
> > I.e. either strip ", update SP and FP" from your introduced comment or
> > which I really like more remove following line with comment entirely:
> > ---------->8----------
> > 	/* Update stack- and frame-pointers */
> > ---------->8----------
> 
> Not sure where you see two SP+FP 'update' comments here; probably
> you're referring to the 'setup' comment on line 53 and the 'update'
> one on line 59. If that is what you meant, I tink these comments are
> different and deserve staying both...

Ok, that's what I have after your patch application:

---------->8----------
	/* Setup stack- and frame-pointers */
	mov	%sp, CONFIG_SYS_INIT_SP_ADDR
	mov	%fp, %sp

	/* Get reserved area size, update SP and FP */
	bl	board_init_f_get_reserve_size
	/* Update stack- and frame-pointers */  <-- that's already mentioned 2 lines above
	sub	%sp, %sp, %r0
	mov	%fp, %sp
---------->8----------


> ... However, these comments also pretty much just paraphrase the code
> which follows them and thus serve little purpose; they could be
> reworded to show less of what is being done and more of why it is being
> done:
> 
> - the "Update stack- and frame-pointer" comment could be turned into
>   "Allocate reserved size on stack and adjust frame pointer
>   accordingly", and
> 
> - the "Setup stack- and frame-pointers" comment could be turned into
>   "Establish C runtime stack and frame".
> 
> Opinions?

Totally agree, care to implement it?

-Alexey