[U-Boot] [PATCH 03/10] x86: Permit bootstage and timer data to be used prior to relocation

[Simon Glass]

Hi Graeme,

On Fri, Dec 14, 2012 at 2:35 PM, Simon Glass <sjg at chromium.org> wrote:

> Hi Graeme,
>
> On Fri, Dec 14, 2012 at 2:15 PM, Graeme Russ <graeme.russ at gmail.com>
> wrote:
> > Hi Simon,
> >
> > On 15/12/12 08:13, Simon Glass wrote:
> >> It is useful to be able to access the timer before U-Boot has relocated
> >> so that we can fully support bootstage.
> >>
> >> Move the relevant variables to the data region to support this.
> >>
> >> Signed-off-by: Simon Glass <sjg at chromium.org>
> >> ---
> >>  arch/x86/cpu/coreboot/coreboot.c |    4 ++--
> >>  arch/x86/cpu/interrupts.c        |    2 +-
> >>  arch/x86/lib/timer.c             |    2 +-
> >>  3 files changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/arch/x86/cpu/coreboot/coreboot.c
> b/arch/x86/cpu/coreboot/coreboot.c
> >> index 9c9431e..22474f5 100644
> >> --- a/arch/x86/cpu/coreboot/coreboot.c
> >> +++ b/arch/x86/cpu/coreboot/coreboot.c
> >> @@ -68,8 +68,8 @@ int board_early_init_r(void)
> >>  void show_boot_progress(int val)
> >>  {
> >>  #if MIN_PORT80_KCLOCKS_DELAY
> >> -     static uint32_t prev_stamp;
> >> -     static uint32_t base;
> >> +     static uint32_t prev_stamp __attribute__((section(".data")));
> >> +     static uint32_t base __attribute__((section(".data")));
> >
> > NAK
> >
> > This may work for coreboot where SDRAM is already initialised and you've
> > loaded U-Boot into RAM, but it will not work when U-Boot is in Flash as
> all
> > sections (including .data) are read-only until after relocation.
> >
> > The stack and Global Data are the only guaranteed read/write locations
> > prior to relocation
>
> Ah yes, I was thinking of your comment that all boards would move to
> use coreboot. If that is not the case, then I will need to add
> something to global data for the timer. And I don't want to do that
> while generic board is in progress since it creates conflicts.
>

Any thoughts on this point, please? I presume at least I can use RAM once
dram_init() is called. But when running from coreboot the RAM is already
set up...

Regards,
Simon


>
> Regards,
> Simon
>
> >
> > Regards,
> >
> > Graeme
> >
>