[U-Boot] [PATCH v2 1/5] string: Provide a slimmed-down memset()

Simon Glass sjg at chromium.org
Wed Apr 5 01:05:51 UTC 2017


On 4 April 2017 at 03:38, Heiko Stübner <heiko at sntech.de> wrote:
>
> Am Sonntag, 2. April 2017, 09:50:28 CEST schrieb Simon Glass:
> > Most of the time the optimised memset() is what we want. For extreme
> > situations such as TPL it may be too large. For example on the 'rock'
> > board, using a simple loop saves a useful 48 bytes. With gcc 4.9 and
> > the rodata bug, this patch is enough to reduce the TPL image below the
> > limit.
> >
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> > ---
> >
> > Changes in v2:
> > - Adjust the option to be SPL-only
> > - Change the option to default to off (name it CONFIG_SPL_TINY_MEMSET)
> >
> >  lib/Kconfig  | 8 ++++++++
> >  lib/string.c | 6 ++++--
> >  2 files changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/Kconfig b/lib/Kconfig
> > index 65c01573e1..58b5717dcd 100644
> > --- a/lib/Kconfig
> > +++ b/lib/Kconfig
> > @@ -52,6 +52,14 @@ config LIB_RAND
> >       help
> >         This library provides pseudo-random number generator functions.
> >
> > +config SPL_TINY_MEMSET
> > +     bool "Use a very small memset() in SPL"
> > +     help
> > +       The faster memset() is the arch-specific one (if available) enabled
> > +       by CONFIG_USE_ARCH_MEMSET. If that is not enabled, we can still get
> > +       better performance by write a word at a time. Enable this option
> > +       to reduce code size slightly at the cost of some speed.
>
> Wording sounds off, I guess we could do something like
>
> [...better performance by] writing a word at a time. In very size-constrained
> environments even this may be to big though. [Enable this option...]
>
> Otherwise
> Reviewed-by: Heiko Stuebner <heiko at sntech.de>

I am going to apply this one now and leave the rest of the series
until it has had a bit more review. But this one is needed for me to
enable the rock board.

Fixed this and:

Applied to u-boot-rockchip


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