From 1c212e3f84de6b824d1ec76b2831450416ba1750 Mon Sep 17 00:00:00 2001
From: David Sidrane <david_s5@nscdg.com>
Date: Wed, 3 Apr 2019 13:14:19 -0700
Subject: [PATCH] M7 dcache ctrl via a parameter (#11769)
* Support for armv7-m_dcache control via parameter
The FORCE_F7_DCACHE parameter can be set to
0 - (default) if Eratta exits turn dcache off else leave it on
1 - Force it off
2 - Force it on
At boot the system will disable the d-cache if the silicon
has the 1259864 Data corruption in a sequence of Write-Through
stores and loads eratta.
Post nsh script execution the FORCE_F7_DCACHE paramater
will be used to set the d-cache to the state indicated
above.
---
boards/av/x-v1/default.cmake | 1 +
boards/av/x-v1/nuttx-config/nsh/defconfig | 3 +
boards/av/x-v1/src/init.c | 29 ++-
boards/px4/fmu-v5/default.cmake | 1 +
boards/px4/fmu-v5/fixedwing.cmake | 1 +
boards/px4/fmu-v5/multicopter.cmake | 1 +
boards/px4/fmu-v5/nuttx-config/nsh/defconfig | 3 +
boards/px4/fmu-v5/rover.cmake | 1 +
boards/px4/fmu-v5/rtps.cmake | 1 +
boards/px4/fmu-v5/src/init.c | 7 +-
boards/px4/fmu-v5/stackcheck.cmake | 1 +
src/drivers/boards/common/CMakeLists.txt | 1 +
.../boards/common/board_dcache_control.c | 178 ++++++++++++++++++
.../boards/common/board_internal_common.h | 64 +++++++
.../stm32/armv7-m_dcache/CMakeLists.txt | 39 ++++
.../stm32/armv7-m_dcache/armv7-m_dcache.cpp | 106 +++++++++++
src/drivers/stm32/armv7-m_dcache/params.c | 49 +++++
17 files changed, 483 insertions(+), 3 deletions(-)
create mode 100644 src/drivers/boards/common/board_dcache_control.c
create mode 100644 src/drivers/stm32/armv7-m_dcache/CMakeLists.txt
create mode 100644 src/drivers/stm32/armv7-m_dcache/armv7-m_dcache.cpp
create mode 100644 src/drivers/stm32/armv7-m_dcache/params.c
diff --git a/boards/av/x-v1/default.cmake b/boards/av/x-v1/default.cmake
index b5869ed989..e19b04e58e 100644
--- a/boards/av/x-v1/default.cmake
+++ b/boards/av/x-v1/default.cmake
@@ -48,6 +48,7 @@ px4_add_board(
roboclaw
stm32
stm32/adc
+ stm32/armv7-m_dcache
#stm32/tone_alarm
tap_esc
telemetry # all available telemetry drivers
diff --git a/boards/av/x-v1/nuttx-config/nsh/defconfig b/boards/av/x-v1/nuttx-config/nsh/defconfig
index f31fd0e9a9..d8ad4f137a 100644
--- a/boards/av/x-v1/nuttx-config/nsh/defconfig
+++ b/boards/av/x-v1/nuttx-config/nsh/defconfig
@@ -41,10 +41,13 @@ CONFIG_ARCH_INTERRUPTSTACK=750
CONFIG_ARCH_MATH_H=y
CONFIG_ARCH_STACKDUMP=y
CONFIG_ARMV7M_BASEPRI_WAR=y
+CONFIG_ARMV7M_DCACHE=y
+CONFIG_ARMV7M_DCACHE_WRITETHROUGH=y
CONFIG_ARMV7M_DTCM=y
CONFIG_ARMV7M_ICACHE=y
CONFIG_ARMV7M_MEMCPY=y
CONFIG_ARMV7M_USEBASEPRI=y
+CONFIG_BOARDCTL_FINALINIT=y
CONFIG_BOARDCTL_RESET=y
CONFIG_BOARD_CRASHDUMP=y
CONFIG_BOARD_LOOPSPERMSEC=43103
diff --git a/boards/av/x-v1/src/init.c b/boards/av/x-v1/src/init.c
index 1b98b25770..ead42eb9f6 100644
--- a/boards/av/x-v1/src/init.c
+++ b/boards/av/x-v1/src/init.c
@@ -1,6 +1,6 @@
/****************************************************************************
*
- * Copyright (c) 2018 PX4 Development Team. All rights reserved.
+ * Copyright (c) 2018-2019 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -150,6 +150,31 @@ __EXPORT void board_on_reset(int status)
}
}
+/****************************************************************************
+ * Name: board_app_finalinitialize
+ *
+ * Description:
+ * Perform application specific initialization. This function is never
+ * called directly from application code, but only indirectly via the
+ * (non-standard) boardctl() interface using the command
+ * BOARDIOC_FINALINIT.
+ *
+ * Input Parameters:
+ * arg - The argument has no meaning.
+ *
+ * Returned Value:
+ * Zero (OK) is returned on success; a negated errno value is returned on
+ * any failure to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_BOARDCTL_FINALINIT
+int board_app_finalinitialize(uintptr_t arg)
+{
+ board_configure_dcache(1);
+ return 0;
+}
+#endif
/************************************************************************************
* Name: stm32_boardinitialize
@@ -166,6 +191,8 @@ stm32_boardinitialize(void)
{
board_on_reset(-1); /* Reset PWM first thing */
+ board_configure_dcache(0);
+
/* configure LEDs */
board_autoled_initialize();
diff --git a/boards/px4/fmu-v5/default.cmake b/boards/px4/fmu-v5/default.cmake
index 127498f4eb..7911119cd8 100644
--- a/boards/px4/fmu-v5/default.cmake
+++ b/boards/px4/fmu-v5/default.cmake
@@ -55,6 +55,7 @@ px4_add_board(
roboclaw
stm32
stm32/adc
+ stm32/armv7-m_dcache
stm32/tone_alarm
tap_esc
telemetry # all available telemetry drivers
diff --git a/boards/px4/fmu-v5/fixedwing.cmake b/boards/px4/fmu-v5/fixedwing.cmake
index 1b2497198e..ee379b6470 100644
--- a/boards/px4/fmu-v5/fixedwing.cmake
+++ b/boards/px4/fmu-v5/fixedwing.cmake
@@ -38,6 +38,7 @@ px4_add_board(
rc_input
stm32
stm32/adc
+ stm32/armv7-m_dcache
stm32/tone_alarm
telemetry # all available telemetry drivers
uavcan
diff --git a/boards/px4/fmu-v5/multicopter.cmake b/boards/px4/fmu-v5/multicopter.cmake
index 1a2002dd98..c13bae7f16 100644
--- a/boards/px4/fmu-v5/multicopter.cmake
+++ b/boards/px4/fmu-v5/multicopter.cmake
@@ -43,6 +43,7 @@ px4_add_board(
roboclaw
stm32
stm32/adc
+ stm32/armv7-m_dcache
stm32/tone_alarm
tap_esc
telemetry # all available telemetry drivers
diff --git a/boards/px4/fmu-v5/nuttx-config/nsh/defconfig b/boards/px4/fmu-v5/nuttx-config/nsh/defconfig
index e5db6f7ba1..f15c8ada53 100644
--- a/boards/px4/fmu-v5/nuttx-config/nsh/defconfig
+++ b/boards/px4/fmu-v5/nuttx-config/nsh/defconfig
@@ -23,10 +23,13 @@ CONFIG_ARCH_INTERRUPTSTACK=750
CONFIG_ARCH_MATH_H=y
CONFIG_ARCH_STACKDUMP=y
CONFIG_ARMV7M_BASEPRI_WAR=y
+CONFIG_ARMV7M_DCACHE=y
+CONFIG_ARMV7M_DCACHE_WRITETHROUGH=y
CONFIG_ARMV7M_DTCM=y
CONFIG_ARMV7M_ICACHE=y
CONFIG_ARMV7M_MEMCPY=y
CONFIG_ARMV7M_USEBASEPRI=y
+CONFIG_BOARDCTL_FINALINIT=y
CONFIG_BOARDCTL_RESET=y
CONFIG_BOARD_CRASHDUMP=y
CONFIG_BOARD_LOOPSPERMSEC=22114
diff --git a/boards/px4/fmu-v5/rover.cmake b/boards/px4/fmu-v5/rover.cmake
index ae10915f6f..bffc8e1191 100644
--- a/boards/px4/fmu-v5/rover.cmake
+++ b/boards/px4/fmu-v5/rover.cmake
@@ -43,6 +43,7 @@ px4_add_board(
roboclaw
stm32
stm32/adc
+ stm32/armv7-m_dcache
stm32/tone_alarm
telemetry # all available telemetry drivers
uavcan
diff --git a/boards/px4/fmu-v5/rtps.cmake b/boards/px4/fmu-v5/rtps.cmake
index 91634838e8..27919988a6 100644
--- a/boards/px4/fmu-v5/rtps.cmake
+++ b/boards/px4/fmu-v5/rtps.cmake
@@ -54,6 +54,7 @@ px4_add_board(
roboclaw
stm32
stm32/adc
+ stm32/armv7-m_dcache
stm32/tone_alarm
tap_esc
telemetry # all available telemetry drivers
diff --git a/boards/px4/fmu-v5/src/init.c b/boards/px4/fmu-v5/src/init.c
index 985ec433fd..b16dda98f6 100644
--- a/boards/px4/fmu-v5/src/init.c
+++ b/boards/px4/fmu-v5/src/init.c
@@ -1,6 +1,6 @@
/****************************************************************************
*
- * Copyright (c) 2012-2016 PX4 Development Team. All rights reserved.
+ * Copyright (c) 2012-2019 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -32,7 +32,7 @@
****************************************************************************/
/**
- * @file px4fmu_init.c
+ * @file init.c
*
* PX4FMU-specific early startup code. This file implements the
* nsh_archinitialize() function that is called early by nsh during startup.
@@ -210,6 +210,7 @@ __EXPORT void board_on_reset(int status)
#ifdef CONFIG_BOARDCTL_FINALINIT
int board_app_finalinitialize(uintptr_t arg)
{
+ board_configure_dcache(1);
return 0;
}
#endif
@@ -229,6 +230,8 @@ stm32_boardinitialize(void)
{
board_on_reset(-1); /* Reset PWM first thing */
+ board_configure_dcache(0);
+
/* configure LEDs */
board_autoled_initialize();
diff --git a/boards/px4/fmu-v5/stackcheck.cmake b/boards/px4/fmu-v5/stackcheck.cmake
index 572acae00a..8bdf660c17 100644
--- a/boards/px4/fmu-v5/stackcheck.cmake
+++ b/boards/px4/fmu-v5/stackcheck.cmake
@@ -54,6 +54,7 @@ px4_add_board(
roboclaw
stm32
stm32/adc
+ stm32/armv7-m_dcache
stm32/tone_alarm
tap_esc
telemetry # all available telemetry drivers
diff --git a/src/drivers/boards/common/CMakeLists.txt b/src/drivers/boards/common/CMakeLists.txt
index 65949e2e6c..d324293887 100644
--- a/src/drivers/boards/common/CMakeLists.txt
+++ b/src/drivers/boards/common/CMakeLists.txt
@@ -38,6 +38,7 @@ if ((${PX4_PLATFORM} MATCHES "nuttx") AND NOT ${PX4_BOARD} MATCHES "io")
board_crashdump.c
board_dma_alloc.c
board_gpio_init.c
+ board_dcache_control.c
)
if (${CONFIG_ARCH_CHIP} MATCHES "kinetis")
diff --git a/src/drivers/boards/common/board_dcache_control.c b/src/drivers/boards/common/board_dcache_control.c
new file mode 100644
index 0000000000..2337a41fa8
--- /dev/null
+++ b/src/drivers/boards/common/board_dcache_control.c
@@ -0,0 +1,178 @@
+/****************************************************************************
+ *
+ * Copyright (C) 2019 PX4 Development Team. All rights reserved.
+ * Author: @author David Sidrane <david_s5@nscdg.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name PX4 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 OWNER 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file board_dcache_control.c
+ * Support for parameter based control of dcache for the
+ * ARM 1259864 Data corruption eratta
+ */
+
+#include <px4_config.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "nvic.h"
+#include "cache.h"
+#include "up_arch.h"
+
+#include <parameters/param.h>
+
+#define CPUID_REVISION_SHIFT 0
+#define CPUID_REVISION_MASK (0xf << CPUID_REVISION_SHIFT)
+#define CPUID_REVISION(cpuid) (((cpuid) & CPUID_REVISION_MASK) >> CPUID_REVISION_SHIFT)
+#define CPUID_PARTNO_SHIFT 4
+#define CPUID_PARTNO_MASK (0xfff << CPUID_PARTNO_SHIFT)
+#define CPUID_PARTNO(cpuid) (((cpuid) & CPUID_PARTNO_MASK) >> CPUID_PARTNO_SHIFT)
+# define CPUID_CORTEX_M7 0xc27
+#define CPUID_VARIANT_SHIFT 20
+#define CPUID_VARIANT_MASK (0xf << CPUID_VARIANT_SHIFT)
+#define CPUID_VARIANT(cpuid) (((cpuid) & CPUID_VARIANT_MASK) >> CPUID_VARIANT_SHIFT)
+#define CPUID_IMPLEMENTER_SHIFT 24
+#define CPUID_IMPLEMENTER_MASK (0xff << CPUID_IMPLEMENTER_SHIFT)
+#define CPUID_IMPLEMENTER(cpuid) (((cpuid) & CPUID_IMPLEMENTER_MASK) >> CPUID_IMPLEMENTER_SHIFT)
+
+#if defined(CONFIG_ARMV7M_DCACHE) && defined(CONFIG_ARMV7M_DCACHE_WRITETHROUGH)
+/************************************************************************************
+ * Name: board_configure_dcache
+ *
+ * Description:
+ * Called at various points in start up to disable the dcache if the
+ * 1259864 Data corruption in a sequence of Write-Through stores and loads
+ * errata is preset.
+ *
+ * Input Parameters:
+ * stage - 0 - early init no OS;
+ * 1 - OS and file system are runnting;
+ *
+ * Returned Value:
+ ************************************************************************************/
+
+void board_configure_dcache(int stage)
+{
+ /* 1259864 Data corruption in a sequence of Write-Through stores and loads
+ * Fault Status: Present in r0p1, r0p2, r1p0 and r1p1. Fixed in r1p2
+ */
+
+ uint32_t cpuid = getreg32(NVIC_CPUID_BASE);
+
+
+ bool erratta = CPUID_PARTNO(cpuid) == CPUID_CORTEX_M7 && (CPUID_VARIANT(cpuid) == 0 || (CPUID_VARIANT(cpuid) == 1
+ && CPUID_REVISION(cpuid) < 2));
+
+ /* On boot we should default to disabled on effected HW */
+
+ if (erratta && stage == 0) {
+ arch_disable_dcache();
+ return;
+ }
+
+ /* Based on a param We can enable the dcache */
+
+ if (stage != 0) {
+
+ int32_t dcache = board_get_dcache_setting();
+
+ switch (dcache) {
+ default:
+ case 0:
+ erratta ? arch_disable_dcache() : arch_enable_dcache();
+ break;
+
+ case 1:
+ arch_disable_dcache();
+ break;
+
+ case 2:
+ arch_enable_dcache();
+ break;
+ return;
+ }
+
+ }
+}
+
+/************************************************************************************
+ * Name: board_dcache_info
+ *
+ * Description:
+ * Called to retrieve dcache info and optionally set dcache to on or off.
+ *
+ * Input Parameters:
+ * action - -1 Provide info only.
+ * pmesg - if non null return the chipid revision and patch level
+ * will indicate if the dcache eratta is present.
+ * state - if non null return the state of the dcache
+ * true on, false is off.
+ *
+ * Returned Value:
+ * 0 - success
+ *
+ ************************************************************************************/
+
+int board_dcache_info(int action, char **pmesg, bool *pstate)
+{
+ uint32_t cpuid = getreg32(NVIC_CPUID_BASE);
+ static char mesg[] = "r?p? has dcache eratta!";
+ bool erratta = (CPUID_PARTNO(cpuid) == CPUID_CORTEX_M7 && (CPUID_VARIANT(cpuid) == 0 || (CPUID_VARIANT(cpuid) == 1
+ && CPUID_REVISION(cpuid) < 2)));
+
+ mesg[1] = '0' + CPUID_VARIANT(cpuid);
+ mesg[3] = '0' + CPUID_REVISION(cpuid);
+
+ if (!erratta) {
+ mesg[5] = 'O';
+ mesg[6] = 'K';
+ mesg[7] = '\0';
+ }
+
+ if (action == 0) {
+ arch_disable_dcache();
+ }
+
+ if (action == 1) {
+ arch_enable_dcache();
+ }
+
+ if (pmesg) {
+ *pmesg = mesg;
+ }
+
+ if (pstate) {
+ *pstate = getreg32(NVIC_CFGCON) & NVIC_CFGCON_DC ? true : false;
+ }
+
+ return 0;
+
+}
+#endif
diff --git a/src/drivers/boards/common/board_internal_common.h b/src/drivers/boards/common/board_internal_common.h
index 47181b473f..a65c819ea9 100644
--- a/src/drivers/boards/common/board_internal_common.h
+++ b/src/drivers/boards/common/board_internal_common.h
@@ -117,3 +117,67 @@ __EXPORT void board_gpio_init(const uint32_t list[], int count);
************************************************************************************/
__EXPORT int board_determine_hw_info(void);
+
+#if defined(CONFIG_ARMV7M_DCACHE) && defined(CONFIG_ARMV7M_DCACHE_WRITETHROUGH)
+/************************************************************************************
+ * Name: board_configure_dcache
+ *
+ * Description:
+ * Called at various points in start up to disable the dcache if the
+ * 1259864 Data corruption in a sequence of Write-Through stores and loads
+ * errata is preset.
+ *
+ * Input Parameters:
+ * stage - 0 - early init no OS;
+ * 1 - OS and file system are runnting;
+ *
+ * Returned Value:
+ * None
+ ************************************************************************************/
+
+void board_configure_dcache(int stage);
+
+/************************************************************************************
+ * Name: board_get_dcache_setting
+ *
+ * Description:
+ * Called to retrieve the parameter setting to enable/disable
+ * the dcache.
+ *
+ * Input Parameters:
+ * None
+ *
+ * Returned Value:
+ * -1 - Not set - if Eratta exits turn dcache off else leave it on
+ * 0 - if Eratta exits turn dcache off else leave it on
+ * 1 - Force it off
+ * 2 - Force it on
+ *
+ ************************************************************************************/
+
+int board_get_dcache_setting(void);
+
+/************************************************************************************
+ * Name: board_dcache_info
+ *
+ * Description:
+ * Called to retrieve dcache info and optionally set dcache to on or off.
+ *
+ * Input Parameters:
+ * action - -1 Provide info only.
+ * pmesg - if non null return the chipid revision and patch level
+ * will indicate if the dcache eratta is present.
+ * state - if non null return the state of the dcache
+ * true on, false is off.
+ *
+ * Returned Value:
+ * 0 - success
+ *
+ ************************************************************************************/
+
+int board_dcache_info(int action, char **pmesg, bool *pstate);
+#else
+# define board_configure_dcache(stage)
+# define board_get_dcache_setting()
+# define board_dcache_info(action, pmesg, pstate)
+#endif
diff --git a/src/drivers/stm32/armv7-m_dcache/CMakeLists.txt b/src/drivers/stm32/armv7-m_dcache/CMakeLists.txt
new file mode 100644
index 0000000000..077cc23a8b
--- /dev/null
+++ b/src/drivers/stm32/armv7-m_dcache/CMakeLists.txt
@@ -0,0 +1,39 @@
+############################################################################
+#
+# Copyright (c) 2015-2019 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+# 2. 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.
+# 3. Neither the name PX4 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 OWNER 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.
+#
+############################################################################
+
+px4_add_module(
+ MODULE drivers__armv7-m_dcache
+ MAIN dcache
+ SRCS
+ armv7-m_dcache.cpp
+ )
diff --git a/src/drivers/stm32/armv7-m_dcache/armv7-m_dcache.cpp b/src/drivers/stm32/armv7-m_dcache/armv7-m_dcache.cpp
new file mode 100644
index 0000000000..37f800c7a6
--- /dev/null
+++ b/src/drivers/stm32/armv7-m_dcache/armv7-m_dcache.cpp
@@ -0,0 +1,106 @@
+/****************************************************************************
+ *
+ * Copyright (C) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name PX4 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 OWNER 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file armv7-m_dcache.cpp
+ *
+ * Driver for the armv7 m_dcache.
+ *
+ */
+
+#include <px4_config.h>
+#include <px4_log.h>
+#include <board_config.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <parameters/param.h>
+
+#include "cache.h"
+
+#if defined(CONFIG_ARMV7M_DCACHE) && defined(CONFIG_ARMV7M_DCACHE_WRITETHROUGH)
+
+extern "C" __EXPORT int dcache_main(int argc, char *argv[]);
+extern "C" __EXPORT int board_get_dcache_setting();
+
+/************************************************************************************
+ * Name: board_get_dcache_setting
+ *
+ * Description:
+ * Called to retrieve the parameter setting to enable/disable
+ * the dcache.
+ *
+ * Input Parameters:
+ * None
+ *
+ * Returned Value:
+ * -1 - Not set - if Eratta exits turn dcache off else leave it on
+ * 0 - if Eratta exits turn dcache off else leave it on
+ * 1 - Force it off
+ * 2 - Force it on
+ *
+ ************************************************************************************/
+
+int board_get_dcache_setting()
+{
+ param_t ph = param_find("SYS_FORCE_F7DC");
+ int32_t dcache_setting = -1;
+
+ if (ph != PARAM_INVALID) {
+ param_get(ph, &dcache_setting);
+ }
+
+ return dcache_setting;
+}
+
+int dcache_main(int argc, char *argv[])
+{
+ int action = -1;
+ char *pmesg = nullptr;
+ bool state = false;
+
+ if (argc > 1) {
+ if (!strcmp(argv[1], "on") || !strcmp(argv[1], "1")) {
+ action = 1;
+ }
+
+ if (!strcmp(argv[1], "off") || !strcmp(argv[1], "0")) {
+ action = 0;
+ }
+ }
+
+ board_dcache_info(action, &pmesg, &state);
+ PX4_INFO("M7 cpuid %s dcache %s", pmesg, state ? "On" : "Off");
+ return 0;
+}
+#endif
diff --git a/src/drivers/stm32/armv7-m_dcache/params.c b/src/drivers/stm32/armv7-m_dcache/params.c
new file mode 100644
index 0000000000..739b2b5f4c
--- /dev/null
+++ b/src/drivers/stm32/armv7-m_dcache/params.c
@@ -0,0 +1,49 @@
+/****************************************************************************
+ *
+ * Copyright (c) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name PX4 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 OWNER 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.
+ *
+ ****************************************************************************/
+
+/**
+ * Force F7 D cache on and disregard errata 1259864 data corruption in
+ * a sequence of write-through stores and loads on ARM M7 silicon
+ * Fault Status: Present in r0p1, r0p2, r1p0 and r1p1. Fixed in r1p2
+ *
+ *
+ * @min 0
+ * @max 2
+ * @value 0 if Eratta exits turn dcache off else leave it on
+ * @value 1 Force it off
+ * @value 2 Force it on
+ * @group Chip
+ * @category Developer
+
+ */
+PARAM_DEFINE_INT32(SYS_FORCE_F7DC, 0);
--
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