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

[Graeme Russ]

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

Regards,

Graeme