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@gmail.com wrote:

From: Anders Darander ad@datarespons.se

Use AT91_GPBR 3 as a bootcount register.

Signed-off-by: Anders Darander ad@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 wrote:

From: Anders Darander ad@datarespons.se

Use AT91_GPBR 3 as a bootcount register.

Signed-off-by: Anders Darander ad@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. */

multi-line comments are /* *Comment lines */

+#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;

implied length of a is 16 bits. the parameter type passed in should be explicitly cast/masked to u16.

I see sharing the 32 bits this way is how mpc5xxx does it..

But

mpc8260, mpc83xx, mpc8xx, ppc4xx, ipx store the bootcount_magic and the parameter as 2 32bit values.

Is there a memory limitation on why you can not follow what most of the others are doing ? If there is, please add the explanation as a comment.

Thank you for pinging me, Tom