[U-Boot] [PATCH] Add bootcount to AT91

[Anders Darander]

Hi all,

As the merge window has closed, I'd just like to bump my old mail
below and ask for comments. Currently the actual register to use is
hard-coded. I'm unsure of what the current status is when it comes to
include new architecture specific CONFIG_*-options.

The bootcount-feature is supported in u-boot for some PPC-boards. The
patch below is basically a rip-off of one of these features, adapted
for the AT91SAM9-architecture. It is tested on an olimex board with an
at91sam9260.

I'd be very happy if we could get this feature mainlined. (I've also
got some replies off-list, from people wanting to use this feature.)

Thanks in advance!
Best regards,
Anders

On Thu, Jan 14, 2010 at 15:00, Anders Darander
<anders.darander at gmail.com> wrote:
> From: Anders Darander <ad at datarespons.se>
>
> Use AT91_GPBR 3 as a bootcount register.
>
> Signed-off-by: Anders Darander <ad at datarespons.se>
> ---
>  cpu/arm926ejs/at91/cpu.c |   28 ++++++++++++++++++++++++++++
>  1 files changed, 28 insertions(+), 0 deletions(-)
>
> diff --git a/cpu/arm926ejs/at91/cpu.c b/cpu/arm926ejs/at91/cpu.c
> index f2f7b62..09c1376 100644
> --- a/cpu/arm926ejs/at91/cpu.c
> +++ b/cpu/arm926ejs/at91/cpu.c
> @@ -31,6 +31,11 @@
>  #define AT91_MAIN_CLOCK 0
>  #endif
>
> +/* The at91sam9260 has 4 GPBR (0-3), we'll use the last one, nr 3,
> + * to keep track of the bootcount. */
> +#define AT91_GPBR_BOOTCOUNT_REGISTER 3
> +#define AT91_BOOTCOUNT_ADDRESS (AT91_GPBR + 4*AT91_GPBR_BOOTCOUNT_REGISTER)
> +
>  int arch_cpu_init(void)
>  {
>        return at91_clock_init(AT91_MAIN_CLOCK);
> @@ -52,3 +57,26 @@ int print_cpuinfo(void)
>        return 0;
>  }
>  #endif
> +
> +#ifdef CONFIG_BOOTCOUNT_LIMIT
> +
> +void bootcount_store (ulong a)
> +{
> +       volatile ulong *save_addr =
> +               (volatile ulong *)(AT91_BASE_SYS + AT91_BOOTCOUNT_ADDRESS);
> +
> +       *save_addr = (BOOTCOUNT_MAGIC & 0xffff0000) | a;
> +}
> +
> +ulong bootcount_load (void)
> +{
> +       volatile ulong *save_addr =
> +               (volatile ulong *)(AT91_BASE_SYS + AT91_BOOTCOUNT_ADDRESS);
> +
> +       if ((*save_addr & 0xffff0000) != (BOOTCOUNT_MAGIC & 0xffff0000))
> +               return 0;
> +       else
> +               return (*save_addr & 0x0000ffff);
> +}
> +
> +#endif /* CONFIG_BOOTCOUNT_LIMIT */
> --
> 1.6.6
>
>



-- 
Anders Darander
EPO guidelines 1978: "If the contribution to the known art resides
solely in a computer program then the subject matter is not
patentable in whatever manner it may be presented in the claims."