[U-Boot] [PATCH v3 2/8] board_init_f_mem(): Don't require memset()

[Albert ARIBAUD]

Hello Simon,

On Sun, 18 Oct 2015 14:38:06 -0600, Simon Glass <sjg at chromium.org>
wrote:
> Hi Albert,
> 
> On 18 October 2015 at 10:28, Albert ARIBAUD <albert.u.boot at aribaud.net> wrote:
> > Hello Simon,
> >
> > On Sat, 17 Oct 2015 15:06:55 -0600, Simon Glass <sjg at chromium.org>
> > wrote:
> >> Unfortunately memset() is not always available, so provide a substitute when
> >> needed.
> >>
> >> Signed-off-by: Simon Glass <sjg at chromium.org>
> >> ---
> >>
> >> Changes in v3: None
> >> Changes in v2:
> >> - Add comments as to why this is needed, deal with arch-specific memset()
> >>
> >>  common/init/board_init.c | 18 ++++++++++++++++++
> >>  1 file changed, 18 insertions(+)
> >>
> >> diff --git a/common/init/board_init.c b/common/init/board_init.c
> >> index e7ebca7..c113a80 100644
> >> --- a/common/init/board_init.c
> >> +++ b/common/init/board_init.c
> >> @@ -11,6 +11,16 @@
> >>
> >>  DECLARE_GLOBAL_DATA_PTR;
> >>
> >> +/*
> >> + * It isn't trivial to figure out whether memcpy() exists. The arch-specific
> >> + * memcpy() is not normally available in SPL due to code size.
> >> + */
> >> +#if !defined(CONFIG_SPL_BUILD) || \
> >> +             (defined(CONFIG_SPL_LIBGENERIC_SUPPORT) && \
> >> +             !defined(CONFIG_USE_ARCH_MEMSET))
> >> +#define _USE_MEMCPY
> >> +#endif
> >> +
> >>  /* Unfortunately x86 can't compile this code as gd cannot be assigned */
> >>  #ifndef CONFIG_X86
> >>  __weak void arch_setup_gd(struct global_data *gd_ptr)
> >> @@ -22,6 +32,9 @@ __weak void arch_setup_gd(struct global_data *gd_ptr)
> >>  ulong board_init_f_mem(ulong top)
> >>  {
> >>       struct global_data *gd_ptr;
> >> +#ifndef _USE_MEMCPY
> >> +     int *ptr, *end;
> >> +#endif
> >>
> >>       /* Leave space for the stack we are running with now */
> >>       top -= 0x40;
> >> @@ -29,7 +42,12 @@ ulong board_init_f_mem(ulong top)
> >>       top -= sizeof(struct global_data);
> >>       top = ALIGN(top, 16);
> >>       gd_ptr = (struct global_data *)top;
> >> +#ifdef _USE_MEMCPY
> >>       memset(gd_ptr, '\0', sizeof(*gd));
> >> +#else
> >> +     for (ptr = (int *)gd_ptr, end = (int *)(gd_ptr + 1); ptr < end; )
> >
> > Nitpick here: There is little point in naming a variable just for
> > it to be set and used once. Without 'end', the compiler will be just as
> > fine if ptr is directly tested against (int *)(gd_ptr + 1), and human
> > readers won't wonder why 'end' was created.
> 
> Well it makes it clear that the ptr goes from the start to the end.
> But it's probably clear enough just doing what you suggest, so I can
> change it.

Please do, thanks!

Amicalement,
-- 
Albert.