TBB: add Trusted Watchdog support on ARM platforms
This patch adds watchdog support on ARM platforms (FVP and Juno).
A secure instance of SP805 is used as Trusted Watchdog. It is
entirely managed in BL1, being enabled in the early platform setup
hook and disabled in the exit hook. By default, the watchdog is
enabled in every build (even when TBB is disabled).
A new ARM platform specific build option `ARM_DISABLE_TRUSTED_WDOG`
has been introduced to allow the user to disable the watchdog at
build time. This feature may be used for testing or debugging
purposes.
Specific error handlers for Juno and FVP are also provided in this
patch. These handlers will be called after an image load or
authentication error. On FVP, the Table of Contents (ToC) in the FIP
is erased. On Juno, the corresponding error code is stored in the
V2M Non-Volatile flags register. In both cases, the CPU spins until
a watchdog reset is generated after 256 seconds (as specified in
the TBBR document).
Change-Id: I9ca11dcb0fe15af5dbc5407ab3cf05add962f4b4
diff --git a/include/plat/arm/common/arm_def.h b/include/plat/arm/common/arm_def.h
index 452c385..4726d5e 100644
--- a/include/plat/arm/common/arm_def.h
+++ b/include/plat/arm/common/arm_def.h
@@ -175,6 +175,15 @@
#define ARM_CONSOLE_BAUDRATE 115200
+/* Trusted Watchdog constants */
+#define ARM_SP805_TWDG_BASE 0x2a490000
+#define ARM_SP805_TWDG_CLK_HZ 32768
+/* The TBBR document specifies a watchdog timeout of 256 seconds. SP805
+ * asserts reset after two consecutive countdowns (2 x 128 = 256 sec) */
+#define ARM_TWDG_TIMEOUT_SEC 128
+#define ARM_TWDG_LOAD_VAL (ARM_SP805_TWDG_CLK_HZ * \
+ ARM_TWDG_TIMEOUT_SEC)
+
/******************************************************************************
* Required platform porting definitions common to all ARM standard platforms
*****************************************************************************/