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

Albert ARIBAUD albert.u.boot at aribaud.net
Mon Nov 16 15:15:27 CET 2015


Hello Alexey,

On Mon, 16 Nov 2015 13:43:19 +0000, Alexey Brodkin
<Alexey.Brodkin at synopsys.com> wrote:
> 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----------

My bad, I'd missed that one. I'll turn

 	/* Get reserved area size, update SP and FP */

Into

 	/* Get reserved area size */

> > ... 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?

That, and the removal of the repetition. v5 in approach.

> -Alexey

Amicalement,
-- 
Albert.


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