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