ARM DaVinci: Reset with watchdog enabled
Once the Davinci watchdog has been enabled, the timeout
value cannot be changed. If the timeout in use is long,
it can take a long time for card to reset. By writing
an invalid service key, we can trigger an immediate reset.
Signed-off-by: Thomas Lange <thomas@corelatus.se>
diff --git a/cpu/arm926ejs/davinci/reset.S b/cpu/arm926ejs/davinci/reset.S
index a687d44..ba0a7c3 100644
--- a/cpu/arm926ejs/davinci/reset.S
+++ b/cpu/arm926ejs/davinci/reset.S
@@ -50,6 +50,10 @@
str r1, [r0]
ldr r1, WDTCR_VAL2
str r1, [r0]
+ /* Write an invalid value to the WDKEY field to trigger
+ * an immediate watchdog reset */
+ mov r1, $0x4000
+ str r1, [r0]
nop
nop
nop