Add bootcount to AT91

Use AT91_GPBR 3 as a bootcount register.
The bootmagic and the bootcount shares AT91_GPBR 3.

Signed-off-by: Anders Darander <ad@datarespons.se>

diff --git a/cpu/arm926ejs/at91/cpu.c b/cpu/arm926ejs/at91/cpu.c
index 1094f8c7f3c28c9c7055de5659be9d2df7d4a2a2..141a7d1ec63d4deb4023e5100b17f32230cdde75 100644 (file)
--- a/cpu/arm926ejs/at91/cpu.c
+++ b/cpu/arm926ejs/at91/cpu.c
@@ -35,6 +35,13 @@
 #define CONFIG_SYS_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(CONFIG_SYS_AT91_MAIN_CLOCK);
@@ -56,3 +63,30 @@ int print_cpuinfo(void)
        return 0;
 }
 #endif
+
+#ifdef CONFIG_BOOTCOUNT_LIMIT
+/*
+ * Just as the mpc5xxx, we combine the BOOTCOUNT_MAGIC and boocount
+ * in one 32-bit register. This is done, as the AT91SAM9260 only has
+ * 4 GPBR.
+ */
+void bootcount_store (ulong a)
+{
+       volatile ulong *save_addr =
+               (volatile ulong *)(AT91_BASE_SYS + AT91_BOOTCOUNT_ADDRESS);
+
+       *save_addr = (BOOTCOUNT_MAGIC & 0xffff0000) | (a & 0x0000ffff);
+}
+
+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 */