Memfault Firmware SDK 1.10.0 (Build 8899)

Author: Memfault Inc

CHANGELOG.md

@@ -6,6 +6,34 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.10.0] - 2024-07-12
+
+### :chart_with_upwards_trend: Improvements
+
+- Zephyr:
+
+  - Add support for Memfault Logging when `CONFIG_LOG_MODE_MINIMAL=y`, in
+    addition to the previously supported `LOG_MODE_DEFERRED` (Zephyr default)
+    and `LOG_MODE_IMMEDIATE`.
+    [Zephyr minimal log mode](https://docs.zephyrproject.org/3.6.0/kconfig.html#CONFIG_LOG_MODE_MINIMAL)
+    disables all backends- logs are simply sent to `printk`.
+
+  - For ESP32 chips, place the reboot reason tracking into a dedicated section,
+    `.rtc_noinit`, to ensure the reboot reason is preserved across reboots. This
+    was previously only supported on Zephyr ESP32-S3/S2 devices (all ESP32
+    devices on ESP-IDF already support this).
+
+  - Fix a bug where the default `memfault_platform_get_device_info()`, which
+    uses the hwinfo subsystem, when available, was incorrectly disabled when
+    `CONFIG_MEMFAULT_REBOOT_REASON_GET_CUSTOM=y`.
+
+- General:
+
+  - Improve the `memfault_demo_cli_cmd_busfault()` function (accessed via
+    `test_busfault`/`mflt test busfault` demo CLI commands) to produce BusFaults
+    on more devices. Previously, certain chips would either not produce a fault,
+    or would produce a MemManage exception instead.
+
 ## [1.9.4] - 2024-07-01
 
 ### :chart_with_upwards_trend: Improvements

VERSION

@@ -1,3 +1,3 @@
-BUILD ID: 8676
-GIT COMMIT: 69ac2e1558
-VERSION: 1.9.4
+BUILD ID: 8899
+GIT COMMIT: 7e534eec9c
+VERSION: 1.10.0

components/demo/src/panics/memfault_demo_panics.c

@@ -172,8 +172,13 @@ int memfault_demo_cli_cmd_memmanage(MEMFAULT_UNUSED int argc, MEMFAULT_UNUSED ch
 }
 
 int memfault_demo_cli_cmd_busfault(MEMFAULT_UNUSED int argc, MEMFAULT_UNUSED char *argv[]) {
-  void (*unaligned_func)(void) = (void (*)(void))0x50000001;
-  unaligned_func();
+  // Trigger a BusFault by attempting to load and jump to an address from the "RAM" (0x60000000 -
+  // 0x7FFFFFFF) region, described as: "Memory with write-back, write allocate cache attribute for
+  // L2/L3 cache support." in the ARMv7-M architecture reference manual. This is not guaranteed to
+  // trigger a BusFault, if the address is both loadable and executable, but on many devices it
+  // will.
+  void (*busfault_func)(void) = (void (*)(void))0x60000001;
+  busfault_func();
 
   // We should never get here -- platforms BusFault or HardFault handler should be tripped
   // with a precise error due to unaligned execution

components/include/memfault/version.h

@@ -19,8 +19,8 @@ typedef struct {
   uint8_t patch;
 } sMfltSdkVersion;
 
-#define MEMFAULT_SDK_VERSION   { .major = 1, .minor = 9, .patch = 4 }
-#define MEMFAULT_SDK_VERSION_STR "1.9.4"
+#define MEMFAULT_SDK_VERSION   { .major = 1, .minor = 10, .patch = 0 }
+#define MEMFAULT_SDK_VERSION_STR "1.10.0"
 
 #ifdef __cplusplus
 }

examples/freertos/boards/qemu_mps2_an385/startup.c

@@ -102,6 +102,10 @@ __attribute__((noinline)) static void prv_cinit(void) {
 }
 
 __attribute__((noreturn)) void Reset_Handler(void) {
+// enable mem/bus/usage faults
+#define SCBSHCSR_ (*(uint32_t *)0xE000ED24)
+  SCBSHCSR_ |= (1UL << 16U) | (1UL << 17U) | (1UL << 18U);
+
   prv_cinit();
 
   uart_init();

examples/freertos/boards/qemu_mps2_an386/startup.c

@@ -102,6 +102,10 @@ __attribute__((noinline)) static void prv_cinit(void) {
 }
 
 __attribute__((noreturn)) void Reset_Handler(void) {
+  // enable mem/bus/usage faults
+#define SCBSHCSR_ (*(uint32_t *)0xE000ED24)
+  SCBSHCSR_ |= (1UL << 16U) | (1UL << 17U) | (1UL << 18U);
+
   prv_cinit();
 
   uart_init();

ports/zephyr/common/CMakeLists.txt

@@ -36,7 +36,10 @@ if (CONFIG_MEMFAULT_LOGGING_ENABLE)
   #    https://github.com/zephyrproject-rtos/zephyr/pull/31535
   # It fully replaced version 1 after the 3.1 release: https://github.com/zephyrproject-rtos/zephyr/issues/46500
   # and the option to enable logging v1 via CONFIG_LOG1 was entirely removed
-  if(${KERNEL_VERSION_MAJOR}.${KERNEL_VERSION_MINOR}.${KERNEL_PATCHLEVEL} VERSION_GREATER_EQUAL "3.1.99" OR CONFIG_LOG2)
+  if(CONFIG_LOG_MODE_MINIMAL)
+    target_link_libraries(app INTERFACE "-Wl,--wrap=z_log_minimal_printk")
+    zephyr_library_sources(memfault_logging_minimal.c)
+  elseif(${KERNEL_VERSION_MAJOR}.${KERNEL_VERSION_MINOR}.${KERNEL_PATCHLEVEL} VERSION_GREATER_EQUAL "3.1.99" OR CONFIG_LOG2)
     zephyr_library_sources(memfault_logging.c)
   else()
     zephyr_library_sources(memfault_logging_legacy.c)
@@ -73,4 +76,8 @@ if(CONFIG_MEMFAULT_HEAP_STATS AND CONFIG_HEAP_MEM_POOL_SIZE GREATER 0)
   zephyr_ld_options(-Wl,--wrap=k_free)
 endif()
 
+if(CONFIG_SOC_FAMILY_ESP32)
+  zephyr_linker_sources(SECTIONS memfault-rtc-noinit-region.ld)
+endif()
+
 zephyr_include_directories(.)

ports/zephyr/common/memfault-rtc-noinit-region.ld

@@ -0,0 +1,19 @@
+/**
+* For ESP32 variants other than ESP32-S3/S2, provide a region of noinit placed
+in * RTC memory, for holding reboot reason information through OTA updates. *
+The normal Zephyr noinit region is not suitable for this, because its offset *
+can change through an OTA update, invalidating the reboot reason data.
+ *
+ * Unfortunately this doesn't place the section in the same order in RTC as in
+ * the ESP32-S3/S2, but it puts it in a usable location.
+ */
+#if !defined(CONFIG_SOC_SERIES_ESP32S3) && !defined(CONFIG_SOC_SERIES_ESP32S2)
+SECTION_PROLOGUE(.rtc_noinit,(NOLOAD),)
+{
+    . = ALIGN(4);
+    _rtc_noinit_start = ABSOLUTE(.);
+    *(.rtc_noinit .rtc_noinit.*)
+    . = ALIGN(4) ;
+    _rtc_noinit_end = ABSOLUTE(.);
+} GROUP_LINK_IN(rtc_slow_seg)
+#endif

ports/zephyr/common/memfault_logging_minimal.c

@@ -0,0 +1,73 @@
+//! @file
+//!
+//! Copyright (c) Memfault, Inc.
+//! See License.txt for details
+//!
+//! @brief
+//! Hooks the Memfault log collection to the Zephyr LOG_MODE_MINIMAL logging
+//! system.
+
+// clang-format off
+#include MEMFAULT_ZEPHYR_INCLUDE(kernel.h)
+#include MEMFAULT_ZEPHYR_INCLUDE(sys/atomic.h)
+#include MEMFAULT_ZEPHYR_INCLUDE(logging/log.h)
+
+#include <stdarg.h>
+
+#include "memfault/components.h"
+// clang-format on
+
+enum {
+  MFLT_LOG_BUFFER_BUSY,
+};
+static atomic_t s_log_output_busy_flag;
+
+static void prv_log_init(void) {
+  // Static RAM storage where logs will be stored.
+  static uint8_t s_mflt_log_buf_storage[CONFIG_MEMFAULT_LOGGING_RAM_SIZE];
+  memfault_log_boot(s_mflt_log_buf_storage, sizeof(s_mflt_log_buf_storage));
+}
+
+static void prv_memfault_log_vprintf(const char *fmt, va_list args) {
+  // Force synchronization at this level.
+  if (atomic_test_and_set_bit(&s_log_output_busy_flag, MFLT_LOG_BUFFER_BUSY)) {
+    return;
+  }
+
+  // This is idempotent; but sensitive to concurrent access. The atomic flag
+  // that protects this function should be good enough, since it only has to
+  // succeed once. The vulnerability is only if a user is accessing
+  // memfault_log_save_preformatted_nolock() directly (should not be done).
+  prv_log_init();
+
+  // Render the log message into a buffer. Static storage class, so it doesn't
+  // contribute to stack usage which could be problematic in this call site.
+  static uint8_t s_zephyr_render_buf[128];
+  int save_length = vsnprintk(s_zephyr_render_buf, sizeof(s_zephyr_render_buf), fmt, args);
+  if (save_length > 0) {
+    // Always set to info, since we can't reliably determine the log level
+    memfault_log_save_preformatted_nolock(kMemfaultPlatformLogLevel_Info, s_zephyr_render_buf,
+                                          save_length);
+  }
+
+  atomic_clear_bit(&s_log_output_busy_flag, MFLT_LOG_BUFFER_BUSY);
+}
+
+void __wrap_z_log_minimal_printk(const char *fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+
+  prv_memfault_log_vprintf(fmt, args);
+
+  va_start(args, fmt);
+
+  // Now call zephyr printk
+  z_log_minimal_vprintk(fmt, args);
+
+  va_end(args);
+}
+
+// Ensure the substituted function signature matches the original function
+_Static_assert(__builtin_types_compatible_p(__typeof__(&z_log_minimal_printk),
+                                            __typeof__(&__wrap_z_log_minimal_printk)),
+               "Error: check z_log_minimal_printk function signature");

ports/zephyr/common/memfault_platform_core.c

@@ -61,7 +61,9 @@ void __wrap_z_arm_fault(uint32_t msp, uint32_t psp, uint32_t exc_return,
   // register capture disable is a very small size optimization, and logs are
   // likely not used on devices with space constraints.
   LOG_PANIC();
+    #if !defined(CONFIG_LOG_MODE_MINIMAL)
   memfault_zephyr_log_backend_disable();
+    #endif
   #endif
 
   memfault_coredump_cache_fault_regs();
@@ -149,26 +151,49 @@ static eMemfaultRebootReason prv_zephyr_to_memfault_reboot_reason(uint32_t reset
 }
   #endif  // CONFIG_HWINFO
 
+MEMFAULT_WEAK void memfault_reboot_reason_get(sResetBootupInfo *info) {
+  eMemfaultRebootReason reset_reason = kMfltRebootReason_Unknown;
+  uint32_t reset_reason_reg = 0;
+  #if defined(CONFIG_HWINFO)
+  int rv = hwinfo_get_reset_cause(&reset_reason_reg);
+
+  if (rv == 0) {
+    reset_reason = prv_zephyr_to_memfault_reboot_reason(reset_reason_reg);
+  }
+
+  #endif
+
+  *info = (sResetBootupInfo){
+    .reset_reason = reset_reason,
+    .reset_reason_reg = reset_reason_reg,
+  };
+}
+#endif
+
+void memfault_zephyr_collect_reset_info(void) {
+  memfault_reboot_tracking_collect_reset_info(s_memfault_event_storage);
+}
+
 // This can be overridden by the application to set a custom device ID
 MEMFAULT_WEAK const char *memfault_zephyr_get_device_id(void) {
   uint8_t dev_id[16] = { 0 };
   static char dev_id_str[sizeof(dev_id) * 2 + 1];
   static const char *dev_str = "UNKNOWN";
 
-  // Obtain the device id
-  #if defined(CONFIG_HWINFO)
+// Obtain the device id
+#if defined(CONFIG_HWINFO)
   ssize_t length = hwinfo_get_device_id(dev_id, sizeof(dev_id));
-  #else
+#else
   ssize_t length = 0;
-  #endif
+#endif
 
   // If hwinfo_get_device_id() fails or isn't enabled, use a fallback string
   if (length <= 0) {
-  #if defined(CONFIG_SOC)
+#if defined(CONFIG_SOC)
     dev_str = CONFIG_SOC "-testserial";
-  #else
+#else
     dev_str = "testserial";
-  #endif
+#endif
     length = strlen(dev_str);
   } else {
     // Render the obtained serial number in hexadecimal representation
@@ -190,29 +215,6 @@ MEMFAULT_WEAK void memfault_platform_get_device_info(sMemfaultDeviceInfo *info)
   };
 }
 
-MEMFAULT_WEAK void memfault_reboot_reason_get(sResetBootupInfo *info) {
-  eMemfaultRebootReason reset_reason = kMfltRebootReason_Unknown;
-  uint32_t reset_reason_reg = 0;
-  #if defined(CONFIG_HWINFO)
-  int rv = hwinfo_get_reset_cause(&reset_reason_reg);
-
-  if (rv == 0) {
-    reset_reason = prv_zephyr_to_memfault_reboot_reason(reset_reason_reg);
-  }
-
-  #endif
-
-  *info = (sResetBootupInfo){
-    .reset_reason = reset_reason,
-    .reset_reason_reg = reset_reason_reg,
-  };
-}
-#endif
-
-void memfault_zephyr_collect_reset_info(void) {
-  memfault_reboot_tracking_collect_reset_info(s_memfault_event_storage);
-}
-
 // Note: the function signature has changed here across zephyr releases
 // "struct device *dev" -> "const struct device *dev"
 //