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

[Anders Darander <anders.darander@gmail.com>]

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