From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?utf-8?Q?Beno=C3=AEt_Th=C3=A9baudeau?= <benoit.thebaudeau@advansee.com>
Date: Wed, 15 May 2013 01:58:23 +0200 (CEST)
Subject: [U-Boot] [PATCH 0/5] Optimize ARM relocation
In-Reply-To: <20130514221601.1b0e939e@lilith>
References: <1368561780-19104-1-git-send-email-albert.u.boot@aribaud.net>
	<20130514221601.1b0e939e@lilith>
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To: u-boot@lists.denx.de

Hi Albert,

On Tuesday, May 14, 2013 10:16:01 PM, Albert ARIBAUD wrote:
> On Tue, 14 May 2013 22:02:55 +0200, Albert ARIBAUD
> <albert.u.boot@aribaud.net> wrote:
> 
> > *** NOTE: this series applies over the 'Factorize
> > ARM relocate_code instances' series.
> > 
> > This series optimizes relocation by ensuring ARM
> > binaries only use one type of relocation record,
> > R_ARM_RELATIVE., then optimizing relocation code
> > accordingly.
> > 
> > The only known case where relocation records other
> > than R_ARM_RELATIVE are generated is when a reference
> > is made to a symbol defined in the linker script, e.g.
> > __image_copy_start, __image_copy_end, __rel_dyn_start,
> > __rel_dyn_end, and __dynsym_start.
> > 
> > Moving the definition of these symbols from the linker
> > scripts into a C module causes their references' types
> > to become R_ARM_RELATIVE.
> > 
> > First, arch/arm/lib/bss.c is replaced by a more generic
> > arch/arm/lib/sections.c where all section symbols will
> > be defined.
> > 
> > Second, __image_copy_start and __image_copy_end symbols
> > are moved from linker scripts to arch/arm/lib/sections.c
> > 
> > Third, __rel_dyn_start, __rel_dyn_end and __synsym_start
> > are moved from linker scripts into arch/arm/lib/sections.c
> > 
> > Fourth, a check is added to the build system to ensure
> > that ELF U-Boot binaries only use R_ARM_RELATIVE records.
> > 
> > Last, relocate_code is optimized
> 
> Hmm, it seems I need to see my work posted on the list to discover how
> I could have done it better... I just noticed that if ARM binaries only
> have R_ARM_RELATIVE record types, then all the .dynsym sections can
> actually be dropped from the binaries. So, if I reorder the series and
> put patch 5/5 first, then I can eliminate patch 3/5, or more to the
> point, replace it with one which eliminates all dynsym stuff from linker
> scripts, further reducing code size. That'll go in V2...

Indeed.

Best regards,
Beno?t