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/docs/user-guide.md b/docs/user-guide.md
index 25f884e..9f9d0a5 100644
--- a/docs/user-guide.md
+++ b/docs/user-guide.md
@@ -428,6 +428,14 @@
in which case the platform is configured to expect NULL in the State-ID
field of power-state parameter.
+* `ARM_DISABLE_TRUSTED_WDOG`: boolean option to disable the Trusted Watchdog.
+ By default, ARM platforms use a watchdog to trigger a system reset in case
+ an error is encountered during the boot process (for example, when an image
+ could not be loaded or authenticated). The watchdog is enabled in the early
+ platform setup hook at BL1 and disabled in the BL1 prepare exit hook. The
+ Trusted Watchdog may be disabled at build time for testing or development
+ purposes.
+
#### ARM CSS platform specific build options
* `CSS_DETECT_PRE_1_7_0_SCP`: Boolean flag to detect SCP version
diff --git a/include/plat/arm/board/common/v2m_def.h b/include/plat/arm/board/common/v2m_def.h
index 7a4ef5a..7ed0af6 100644
--- a/include/plat/arm/board/common/v2m_def.h
+++ b/include/plat/arm/board/common/v2m_def.h
@@ -38,6 +38,9 @@
#define V2M_SYS_ID 0x0
#define V2M_SYS_SWITCH 0x4
#define V2M_SYS_LED 0x8
+#define V2M_SYS_NVFLAGS 0x38
+#define V2M_SYS_NVFLAGSSET 0x38
+#define V2M_SYS_NVFLAGSCLR 0x3c
#define V2M_SYS_CFGDATA 0xa0
#define V2M_SYS_CFGCTRL 0xa4
#define V2M_SYS_CFGSTATUS 0xa8
@@ -109,7 +112,11 @@
#define V2M_SP804_TIMER0_BASE 0x1C110000
#define V2M_SP804_TIMER1_BASE 0x1C120000
-#define V2M_MAP_FLASH0 MAP_REGION_FLAT(V2M_FLASH0_BASE,\
+#define V2M_MAP_FLASH0_RW MAP_REGION_FLAT(V2M_FLASH0_BASE,\
+ V2M_FLASH0_SIZE, \
+ MT_DEVICE | MT_RW | MT_SECURE)
+
+#define V2M_MAP_FLASH0_RO MAP_REGION_FLAT(V2M_FLASH0_BASE,\
V2M_FLASH0_SIZE, \
MT_MEMORY | MT_RO | MT_SECURE)
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
*****************************************************************************/
diff --git a/plat/arm/board/common/board_common.mk b/plat/arm/board/common/board_common.mk
index bec49ed..9e0c848 100644
--- a/plat/arm/board/common/board_common.mk
+++ b/plat/arm/board/common/board_common.mk
@@ -28,14 +28,15 @@
# POSSIBILITY OF SUCH DAMAGE.
#
-PLAT_INCLUDES += -Iinclude/plat/arm/board/common/
+PLAT_INCLUDES += -Iinclude/plat/arm/board/common/ \
+ -Iinclude/plat/arm/board/common/drivers
PLAT_BL_COMMON_SOURCES += drivers/arm/pl011/pl011_console.S \
plat/arm/board/common/aarch64/board_arm_helpers.S
-#BL1_SOURCES +=
+BL1_SOURCES += plat/arm/board/common/drivers/norflash/norflash.c
-#BL2_SOURCES +=
+BL2_SOURCES += plat/arm/board/common/drivers/norflash/norflash.c
#BL31_SOURCES +=
diff --git a/plat/arm/board/common/board_css_common.c b/plat/arm/board/common/board_css_common.c
index 3bb3dd6..7bf0273 100644
--- a/plat/arm/board/common/board_css_common.c
+++ b/plat/arm/board/common/board_css_common.c
@@ -38,7 +38,7 @@
#if IMAGE_BL1
const mmap_region_t plat_arm_mmap[] = {
ARM_MAP_SHARED_RAM,
- V2M_MAP_FLASH0,
+ V2M_MAP_FLASH0_RO,
V2M_MAP_IOFPGA,
CSS_MAP_DEVICE,
SOC_CSS_MAP_DEVICE,
@@ -48,7 +48,7 @@
#if IMAGE_BL2
const mmap_region_t plat_arm_mmap[] = {
ARM_MAP_SHARED_RAM,
- V2M_MAP_FLASH0,
+ V2M_MAP_FLASH0_RO,
V2M_MAP_IOFPGA,
CSS_MAP_DEVICE,
SOC_CSS_MAP_DEVICE,
diff --git a/plat/arm/board/fvp/aarch64/fvp_common.c b/plat/arm/board/fvp/aarch64/fvp_common.c
index 58b646a..8771e5b 100644
--- a/plat/arm/board/fvp/aarch64/fvp_common.c
+++ b/plat/arm/board/fvp/aarch64/fvp_common.c
@@ -68,7 +68,7 @@
#if IMAGE_BL1
const mmap_region_t plat_arm_mmap[] = {
ARM_MAP_SHARED_RAM,
- V2M_MAP_FLASH0,
+ V2M_MAP_FLASH0_RW,
V2M_MAP_IOFPGA,
MAP_DEVICE0,
MAP_DEVICE1,
@@ -79,7 +79,7 @@
#if IMAGE_BL2
const mmap_region_t plat_arm_mmap[] = {
ARM_MAP_SHARED_RAM,
- V2M_MAP_FLASH0,
+ V2M_MAP_FLASH0_RW,
V2M_MAP_IOFPGA,
MAP_DEVICE0,
MAP_DEVICE1,
diff --git a/plat/arm/board/fvp/fvp_err.c b/plat/arm/board/fvp/fvp_err.c
new file mode 100644
index 0000000..7867e49
--- /dev/null
+++ b/plat/arm/board/fvp/fvp_err.c
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <board_arm_def.h>
+#include <debug.h>
+#include <errno.h>
+#include <norflash.h>
+#include <stdint.h>
+
+/*
+ * FVP error handler
+ */
+void plat_error_handler(int err)
+{
+ int ret;
+
+ switch (err) {
+ case -ENOENT:
+ case -EAUTH:
+ /* Image load or authentication error. Erase the ToC */
+ INFO("Erasing FIP ToC from flash...\n");
+ nor_unlock(PLAT_ARM_FIP_BASE);
+ ret = nor_word_program(PLAT_ARM_FIP_BASE, 0);
+ if (ret) {
+ ERROR("Cannot erase ToC\n");
+ } else {
+ INFO("Done\n");
+ }
+ break;
+ default:
+ /* Unexpected error */
+ break;
+ }
+
+ /* Loop until the watchdog resets the system */
+ for (;;)
+ ;
+}
diff --git a/plat/arm/board/fvp/platform.mk b/plat/arm/board/fvp/platform.mk
index 51b718e..c46d3b7 100644
--- a/plat/arm/board/fvp/platform.mk
+++ b/plat/arm/board/fvp/platform.mk
@@ -41,6 +41,7 @@
lib/semihosting/aarch64/semihosting_call.S \
plat/arm/board/fvp/aarch64/fvp_helpers.S \
plat/arm/board/fvp/fvp_bl1_setup.c \
+ plat/arm/board/fvp/fvp_err.c \
plat/arm/board/fvp/fvp_io_storage.c
BL2_SOURCES += drivers/arm/sp804/sp804_delay_timer.c \
@@ -49,6 +50,7 @@
lib/semihosting/semihosting.c \
lib/semihosting/aarch64/semihosting_call.S \
plat/arm/board/fvp/fvp_bl2_setup.c \
+ plat/arm/board/fvp/fvp_err.c \
plat/arm/board/fvp/fvp_io_storage.c \
plat/arm/board/fvp/fvp_security.c
diff --git a/plat/arm/board/juno/juno_err.c b/plat/arm/board/juno/juno_err.c
new file mode 100644
index 0000000..497cc7f
--- /dev/null
+++ b/plat/arm/board/juno/juno_err.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <v2m_def.h>
+
+#define V2M_SYS_NVFLAGS_ADDR (V2M_SYSREGS_BASE + V2M_SYS_NVFLAGS)
+
+/*
+ * Juno error handler
+ */
+void plat_error_handler(int err)
+{
+ uint32_t *flags_ptr = (uint32_t *)V2M_SYS_NVFLAGS_ADDR;
+
+ /* Propagate the err code in the NV-flags register */
+ *flags_ptr = err;
+
+ /* Loop until the watchdog resets the system */
+ for (;;)
+ ;
+}
diff --git a/plat/arm/board/juno/platform.mk b/plat/arm/board/juno/platform.mk
index b711f3d..127dcbe 100644
--- a/plat/arm/board/juno/platform.mk
+++ b/plat/arm/board/juno/platform.mk
@@ -34,9 +34,11 @@
BL1_SOURCES += lib/cpus/aarch64/cortex_a53.S \
lib/cpus/aarch64/cortex_a57.S \
- lib/cpus/aarch64/cortex_a72.S
+ lib/cpus/aarch64/cortex_a72.S \
+ plat/arm/board/juno/juno_err.c
BL2_SOURCES += plat/arm/board/juno/juno_security.c \
+ plat/arm/board/juno/juno_err.c
BL31_SOURCES += lib/cpus/aarch64/cortex_a53.S \
lib/cpus/aarch64/cortex_a57.S \
diff --git a/plat/arm/common/arm_bl1_setup.c b/plat/arm/common/arm_bl1_setup.c
index 887223c..79c7d94 100644
--- a/plat/arm/common/arm_bl1_setup.c
+++ b/plat/arm/common/arm_bl1_setup.c
@@ -35,6 +35,7 @@
#include <console.h>
#include <platform_def.h>
#include <plat_arm.h>
+#include <sp805.h>
#include "../../../bl1/bl1_private.h"
@@ -74,6 +75,11 @@
{
const size_t bl1_size = BL1_RAM_LIMIT - BL1_RAM_BASE;
+#if !ARM_DISABLE_TRUSTED_WDOG
+ /* Enable watchdog */
+ sp805_start(ARM_SP805_TWDG_BASE, ARM_TWDG_LOAD_VAL);
+#endif
+
/* Initialize the console to provide early debug support */
console_init(PLAT_ARM_BOOT_UART_BASE, PLAT_ARM_BOOT_UART_CLK_IN_HZ,
ARM_CONSOLE_BAUDRATE);
@@ -147,6 +153,11 @@
void bl1_plat_prepare_exit(entry_point_info_t *ep_info)
{
+#if !ARM_DISABLE_TRUSTED_WDOG
+ /* Disable watchdog before leaving BL1 */
+ sp805_stop(ARM_SP805_TWDG_BASE);
+#endif
+
#ifdef EL3_PAYLOAD_BASE
/*
* Program the EL3 payload's entry point address into the CPUs mailbox
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index 7b23527..1290cef 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -63,6 +63,15 @@
$(eval $(call assert_boolean,ARM_RECOM_STATE_ID_ENC))
$(eval $(call add_define,ARM_RECOM_STATE_ID_ENC))
+# Process ARM_DISABLE_TRUSTED_WDOG flag
+# By default, Trusted Watchdog is always enabled unless SPIN_ON_BL1_EXIT is set
+ARM_DISABLE_TRUSTED_WDOG := 0
+ifeq (${SPIN_ON_BL1_EXIT}, 1)
+ARM_DISABLE_TRUSTED_WDOG := 1
+endif
+$(eval $(call assert_boolean,ARM_DISABLE_TRUSTED_WDOG))
+$(eval $(call add_define,ARM_DISABLE_TRUSTED_WDOG))
+
PLAT_INCLUDES += -Iinclude/common/tbbr \
-Iinclude/plat/arm/common \
-Iinclude/plat/arm/common/aarch64
@@ -75,6 +84,7 @@
BL1_SOURCES += drivers/arm/cci/cci.c \
drivers/arm/ccn/ccn.c \
+ drivers/arm/sp805/sp805.c \
drivers/io/io_fip.c \
drivers/io/io_memmap.c \
drivers/io/io_storage.c \
