add coredump RPC

.github/workflows/nightly.yml

@@ -637,6 +637,7 @@ jobs:
         example:
           - path: micropython/esp32
           - path: esp32/uart-bridge
+          - path: esp32/minimal
     name: ${{ matrix.example.path }}
     env:
       GO: 0

.github/workflows/quicktest.yml

@@ -186,6 +186,7 @@ jobs:
       matrix:
         example:
           - path: esp32/uart-bridge
+          - path: esp32/minimal
     name: ${{ matrix.example.path }}
     env:
       GO: 0

mongoose.c

@@ -3641,12 +3641,66 @@ struct mg_fs mg_fs_posix = {p_stat,  p_list, p_open,   p_close,  p_read,
 
 
 
+#if MG_ENABLE_HEALTH
+#if MG_ARCH == MG_ARCH_ESP32
+// reusable for other platforms, currently ESP32-only
+struct mg_health_coredump {
+  const void *ptr;
+  size_t poffset;
+  size_t size;
+};
+
+static struct mg_health_coredump s_coredump;
+#endif
+
+bool mg_health_coredump_begin(size_t *size) {
+#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+  const esp_partition_t *p = esp_partition_find_first(
+      ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_COREDUMP, NULL);
+  size_t address = 0, len = 0;
+  esp_err_t err = esp_core_dump_image_get(&address, &len);
+  if (size == NULL || s_coredump.ptr != NULL || err != ESP_OK || p == NULL)
+    return false;
+  s_coredump.ptr = p;
+  s_coredump.poffset = address - p->address;
+  s_coredump.size = len;
+  *size = len;
+  return true;
+#else
+  (void) size;
+  return false;
+#endif
+}
+
+bool mg_health_coredump_read(size_t offset, void *buf, size_t *len) {
+#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+  const esp_partition_t *p = (const esp_partition_t *) s_coredump.ptr;
+  if (p == NULL || offset > s_coredump.size)
+    return false;
+  if (*len > s_coredump.size - offset) *len = s_coredump.size - offset;
+  return esp_partition_read(p, s_coredump.poffset + offset, buf, *len) == ESP_OK;
+#else
+  (void) offset, (void) buf, (void) len;
+  return false;
+#endif
+}
+
+bool mg_health_coredump_end(void) {
+#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+  bool ok = s_coredump.ptr != NULL;
+  memset(&s_coredump, 0, sizeof(s_coredump));
+  return ok;
+#else
+  return false;
+#endif
+}
+
 // The one health record. Lives in RAM that survives a warm reset, see
 // MG_HEALTH_RAM and the .mg_health region in the linker script
 struct mg_health mg_health_record MG_HEALTH_RAM;
 
-// STM32 H723 support. Needs the _estack symbol from the linker script
-#if MG_ENABLE_HEALTH && (defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5))
+// STM32 H7, H5, C5 support. Needs the _estack symbol from the linker script
+#if defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5)
 // Fault handler body. Runs in exception context: no printf, no malloc, no
 // blocking calls. Copies the unwind registers and raw stack into the health
 // record, then resets.
@@ -3688,52 +3742,57 @@ void BusFault_Handler(void) __attribute__((alias("HardFault_Handler")));
 void UsageFault_Handler(void) __attribute__((alias("HardFault_Handler")));
 #endif
 
-// Start a new boot: validate the record, count the boot, store the reset
-// reason. The current boot moves to prev_* slots first, so the previous
-// boot's uptime and reason stay readable. Called by MG_HEALTH_INIT()
+// Start a new boot: validate the record. Called by MG_HEALTH_INIT()
 void mg_health_init(void) {
   char magic[] = MG_HEALTH_MAGIC;
-  // struct mg_health *h = mg_health_get();
   if (!mg_health_valid()) {  // First boot, or RAM lost its contents
     memset(&mg_health_record, 0, sizeof(mg_health_record));
     memcpy(mg_health_record.magic, magic, sizeof(mg_health_record.magic));
   }
-
-#if 0 && MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-  {
+#if MG_ARCH == MG_ARCH_ESP32
+#if CONFIG_IDF_TARGET_ARCH_XTENSA
+  mg_health_record.arch = (uint16_t) MG_HEALTH_ARCH_XTENSA;
+#elif CONFIG_IDF_TARGET_ARCH_RISCV
+  mg_health_record.arch = (uint16_t) MG_HEALTH_ARCH_RISCV;
+#endif
+  esp_reset_reason_t rr = esp_reset_reason();
+  mg_health_record.reset_reason = esp2mg(rr);
+#if CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH == 0
+  MG_ERROR(("MG_HEALTH is enabled but CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH=n"));
+#else
     // After a crash, copy the backtrace from the core dump in flash: the same
     // addresses the panic handler prints as "Backtrace: PC:SP PC:SP ...".
     // The core dump stays in flash, so check the reset reason, otherwise an
     // old crash is reported on every boot
-    static esp_core_dump_summary_t s;  // Big on RISC-V, keep it off the stack
-    esp_reset_reason_t rr = esp_reset_reason();
+    esp_core_dump_summary_t *s = calloc(1, sizeof(*s));
     uint32_t *out = mg_health_record.data;
-    size_t n = 0, max = MG_HEALTH_DATA_SIZE;
-    if (rr != ESP_RST_PANIC && rr != ESP_RST_INT_WDT && rr != ESP_RST_TASK_WDT)
-      return;  // Not a crash that went through the panic handler
-    if (max == 0 || esp_core_dump_get_summary(&s) != ESP_OK) return;
-
-    mg_health_record.cpuid = 42;  // ESP32
-    mg_health_record.reset_reason = MG_HEALTH_RESET_FAULT;
-
+    size_t n = 0;
     memset(out, 0, sizeof(mg_health_record.data));
-    out[n++] = s.exc_pc;
+    if (s == NULL) return;
+    if ((rr != ESP_RST_PANIC && rr != ESP_RST_INT_WDT &&
+         rr != ESP_RST_TASK_WDT)  // Not a crash caught by the panic handler
+        || esp_core_dump_get_summary(s) != ESP_OK) {
+      free(s);
+      return;
+    }
+    out[n++] = s->exc_pc;
+    memcpy(&out[n], s->exc_task, 16), n += 4;
 #if CONFIG_IDF_TARGET_ARCH_XTENSA
-    for (uint32_t i = 0; i < s.exc_bt_info.depth && n < max; i++) {
-      if (s.exc_bt_info.bt[i] != s.exc_pc) out[n++] = s.exc_bt_info.bt[i];
-    }
+    out[n++] = s->ex_info.exc_a[0];
+    out[n++] = s->ex_info.exc_a[1];
+    size_t len = s->exc_bt_info.depth;
+    if (len > MG_HEALTH_DATA_SIZE - n) len = (MG_HEALTH_DATA_SIZE - n);
+    memcpy(&out[n], s->exc_bt_info.bt, 4 * len); // sizeof(uint32_t)
 #elif CONFIG_IDF_TARGET_ARCH_RISCV
-    // No unwinder: take the return address, then words on the stack that
-    // point into executable memory (a heuristic, may include stale values)
-    if (n < max) out[n++] = s.ex_info.ra;
-    for (uint32_t i = 0; i + 4 <= s.exc_bt_info.dump_size && n < max; i += 4) {
-      uint32_t w;
-      memcpy(&w, &s.exc_bt_info.stackdump[i], sizeof(w));  // Byte array
-      if (esp_ptr_executable((void *) (uintptr_t) w)) out[n++] = w;
-    }
-#endif
-  }
+    out[n++] = s->ex_info.exc_ra;
+    out[n++] = s->ex_info.exc_sp;
+    size_t len = s->exc_bt_info.dump_size / 4 ; // sizeof(uint32_t)
+    if (len > MG_HEALTH_DATA_SIZE - n) len = (MG_HEALTH_DATA_SIZE - n);
+    memcpy(&out[n], s->exc_bt_info.stackdump, 4 * len);
 #endif
+    free(s);
+#endif  // CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+#endif  // MG_ARCH_ESP32
 }
 
 static size_t print_uint32(void (*fn)(char, void *), void *arg, va_list *ap) {
@@ -3747,11 +3806,17 @@ static size_t print_uint32(void (*fn)(char, void *), void *arg, va_list *ap) {
 size_t mg_print_crash_record(void (*fn)(char, void *), void *arg, va_list *ap) {
   size_t len = 0;
   if (mg_health_valid() &&
-      mg_health_record.reset_reason == MG_HEALTH_RESET_FAULT) {
+      (mg_health_record.reset_reason == (uint16_t) MG_HEALTH_RESET_FAULT
+#if MG_ARCH == MG_ARCH_ESP32
+       || mg_health_record.reset_reason == (uint16_t) MG_HEALTH_RESET_WATCHDOG
+#endif
+       )) {
     size_t n = sizeof(mg_health_record.data) / sizeof(mg_health_record.data[0]);
-    len += mg_xprintf(fn, arg, "{%m:%hhu,%m:%u,%m:[%M]}",            //
-                      MG_ESC("version"), mg_health_record.magic[3],  //
-                      MG_ESC("cpuid"), mg_health_record.cpuid,       //
+    len += mg_xprintf(fn, arg, "{%m:%hhu,%m:%hu,%m:%hu,%m:%u,%m:[%M]}",  //
+                      MG_ESC("version"), mg_health_record.magic[3],      //
+                      MG_ESC("arch"), mg_health_record.arch,             //
+                      MG_ESC("reason"), mg_health_record.reset_reason,   //
+                      MG_ESC("cpuid"), mg_health_record.cpuid,           //
                       MG_ESC("data"), print_uint32, n, mg_health_record.data);
   } else {
     len += mg_xprintf(fn, arg, "{}");
@@ -3759,6 +3824,7 @@ size_t mg_print_crash_record(void (*fn)(char, void *), void *arg, va_list *ap) {
   (void) ap;
   return len;
 }
+#endif
 
 #ifdef MG_ENABLE_LINES
 #line 1 "src/http.c"
@@ -7338,6 +7404,7 @@ static void mg_mdash_fn(struct mg_connection *c, int ev, void *ev_data) {
     }
     mg_iobuf_free(&io);
   } else if (ev == MG_EV_CLOSE) {
+    mg_health_coredump_end();
     mg_mdash_conn = NULL;
     MG_INFO(("disconnected, ram %lu", 0));
   }
@@ -7395,6 +7462,35 @@ static void mg_mdash_rpc_ota_end(struct mg_rpc_req *r) {
   // MG_ESC("percent"));
 }
 
+static void rpc_coredump_begin(struct mg_rpc_req *r) {
+  size_t size = 0;
+  if (mg_health_coredump_begin(&size)) {
+    mg_rpc_ok(r, "{%m:%llu}", MG_ESC("size"), (uint64_t) size);
+  } else {
+    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
+  }
+}
+
+static void rpc_coredump_read(struct mg_rpc_req *r) {
+  uint8_t buf[768];
+  size_t len = sizeof(buf);
+  size_t offset = (size_t) mg_json_get_long(r->frame, "$.params.offset", -1);
+  if (mg_health_coredump_read(offset, buf, &len)) {
+    mg_rpc_ok(r, "{%m:\"%M\"}", MG_ESC("data"), mg_print_base64,
+              (int) len, buf);
+  } else {
+    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
+  }
+}
+
+static void rpc_coredump_end(struct mg_rpc_req *r) {
+  if (mg_health_coredump_end()) {
+    mg_rpc_ok(r, "true");
+  } else {
+    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
+  }
+}
+
 void mg_mdash_init(struct mg_mgr *mgr) {
   MG_INFO(("Initialising mdash agent, key [%s]", MG_MDASH_KEY));
   mg_rpc_add(&mgr->rpcs, mg_str("RPC.List"), mg_rpc_list, NULL);
@@ -7402,6 +7498,9 @@ void mg_mdash_init(struct mg_mgr *mgr) {
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.Begin"), mg_mdash_rpc_ota_begin, NULL);
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.Write"), mg_mdash_rpc_ota_write, NULL);
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.End"), mg_mdash_rpc_ota_end, NULL);
+  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.Begin"), rpc_coredump_begin, NULL);
+  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.Read"), rpc_coredump_read, NULL);
+  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.End"), rpc_coredump_end, NULL);
 }
 
 void mg_mdash_poll(struct mg_mgr *mgr) {
@@ -34937,6 +35036,7 @@ struct mg_tcpip_driver mg_tcpip_driver_stm32f = {
 
 #if MG_ENABLE_TCPIP && (MG_ENABLE_DRIVER_STM32H || MG_ENABLE_DRIVER_MCXN || \
                         MG_ENABLE_DRIVER_STM32N)
+// STM32C: vendor modded single-queue Synopsys v5.4, same settings as STM32H
 // STM32H: vendor modded single-queue Synopsys v4.2
 // STM32N: dual-queue GbE Synopsys v5.2 with no hash table option, 64-bit AXI
 // MCXNx4x: dual-queue Synopsys v5.2 with no hash table option

mongoose.h

@@ -253,8 +253,11 @@ extern "C" {
 #include <esp_system.h>
 #include <esp_mac.h>
 #include <esp_idf_version.h>
-// #include <esp_memory_utils.h>  // For health record coredumps
-// #include <esp_core_dump.h>     // For health record coredumps
+#if MG_ENABLE_HEALTH
+#include <esp_memory_utils.h>
+#include <esp_core_dump.h>
+#include <esp_partition.h>
+#endif
 
 #define MG_PATH_MAX 128
 
@@ -4371,6 +4374,8 @@ void mg_ota_poll(struct mg_mgr *);
 
 
 
+#if MG_ENABLE_HEALTH
+
 #ifndef MG_HEALTH_MAGIC
 #define MG_HEALTH_MAGIC {'M', 'G', 'H', '3'}  // '3' is the layout version
 #endif
@@ -4379,13 +4384,15 @@ void mg_ota_poll(struct mg_mgr *);
 #define MG_HEALTH_RAM __attribute__((section(".mg_health")))
 #endif
 
-#if !defined(MG_HEALTH_DATA_SIZE) && (defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5))
-#define MG_HEALTH_DATA_SIZE 250
-#endif
-
 #ifndef MG_HEALTH_DATA_SIZE
+#if (defined(STM32H7_DEV_ID) || defined(STM32H5)) || defined(STM32C5)
+#define MG_HEALTH_DATA_SIZE 250
+#elif MG_ARCH == MG_ARCH_ESP32
+#define MG_HEALTH_DATA_SIZE 23
+#else
 #define MG_HEALTH_DATA_SIZE 10
 #endif
+#endif  // MG_HEALTH_DATA_SIZE
 
 // Places the record in RAM that survives a reset. Define in mongoose_config.h
 // to match the linker script, e.g. __attribute__((section(".mg_health")))
@@ -4393,6 +4400,13 @@ void mg_ota_poll(struct mg_mgr *);
 #define MG_HEALTH_RAM
 #endif
 
+// CPU core architecture
+enum mg_health_arch {
+  MG_HEALTH_ARCH_ARM = 0,
+  MG_HEALTH_ARCH_XTENSA,
+  MG_HEALTH_ARCH_RISCV
+};
+
 // Why the device restarted. Hardware usually reports several flags at once,
 // so these are ordered by how much they tell you: the most specific cause a
 // device reports wins
@@ -4409,7 +4423,8 @@ enum mg_health_reason {
 
 struct mg_health {
   char magic[4];          // MG_HEALTH_MAGIC when the record holds valid data
-  uint32_t reset_reason;  // enum mg_health_reason that started this boot
+  uint16_t reset_reason;  // enum mg_health_reason that started this boot
+  uint16_t arch;          // enum mg_health_arch, core architecture (ARM, etc)
   uint32_t cpuid;         // ARM CPU ID
   uint32_t data[MG_HEALTH_DATA_SIZE];
 };
@@ -4442,9 +4457,72 @@ static inline const char *mg_health_reason_str(int reason) {
   }
 }
 
+#if MG_ARCH == MG_ARCH_ESP32
+#ifndef CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+#define CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH 0
+#endif
+#ifndef ESP_PARTITION_SUBTYPE_DATA_COREDUMP
+#define ESP_PARTITION_SUBTYPE_DATA_COREDUMP 0x03
+#endif
+// clang-format off
+static inline uint16_t esp2mg(esp_reset_reason_t rr) {
+  switch(rr) {
+    case ESP_RST_POWERON: return (uint16_t) MG_HEALTH_RESET_POWER;
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 2)
+    case ESP_RST_PWR_GLITCH:
+#endif
+    case ESP_RST_BROWNOUT: return (uint16_t) MG_HEALTH_RESET_BROWNOUT;
+    case ESP_RST_EXT: return (uint16_t) MG_HEALTH_RESET_PIN;
+    case ESP_RST_SW: return (uint16_t) MG_HEALTH_RESET_SOFTWARE;
+    case ESP_RST_DEEPSLEEP: return (uint16_t) MG_HEALTH_RESET_LOWPOWER;
+    case ESP_RST_INT_WDT:
+    case ESP_RST_TASK_WDT:
+    case ESP_RST_WDT: return (uint16_t) MG_HEALTH_RESET_WATCHDOG;
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 2)
+    case ESP_RST_CPU_LOCKUP:
+#endif
+    case ESP_RST_PANIC: return (uint16_t) MG_HEALTH_RESET_FAULT;
+    default: break;
+  }
+  return (uint16_t) MG_HEALTH_RESET_UNKNOWN;
+}
+// clang-format on
+#endif
+
 #define MG_HEALTH_INIT() mg_health_init()
 extern size_t mg_print_crash_record(mg_pfn_t, void *, va_list *);
 extern void mg_health_init(void);
+extern bool mg_health_coredump_begin(size_t *size);
+extern bool mg_health_coredump_read(size_t offset, void *buf, size_t *len);
+extern bool mg_health_coredump_end(void);
+#else
+#define MG_HEALTH_INIT()
+static inline int mg_health_reason(void) {
+  return 0;
+}
+static inline const char *mg_health_reason_str(int reason) {
+  (void) reason;
+  return "unknown";
+}
+static inline size_t mg_print_crash_record(mg_pfn_t fn, void *arg,
+                                           va_list *ap) {
+  (void) ap;
+  return mg_xprintf(fn, arg, "{}");
+}
+static inline bool mg_health_coredump_begin(size_t *size) {
+  (void) size;
+  return false;
+}
+static inline bool mg_health_coredump_read(size_t offset, void *buf,
+                                           size_t *len) {
+  (void) offset, (void) buf, (void) len;
+  return false;
+}
+static inline bool mg_health_coredump_end(void) {
+  return false;
+}
+
+#endif
 // Cloud connector API to https://mdash.net - device management cloud
 
 

src/arch_esp32.h

@@ -22,8 +22,11 @@
 #include <esp_system.h>
 #include <esp_mac.h>
 #include <esp_idf_version.h>
-// #include <esp_memory_utils.h>  // For health record coredumps
-// #include <esp_core_dump.h>     // For health record coredumps
+#if MG_ENABLE_HEALTH
+#include <esp_memory_utils.h>
+#include <esp_core_dump.h>
+#include <esp_partition.h>
+#endif
 
 #define MG_PATH_MAX 128
 

src/health.c

@@ -1,12 +1,66 @@
 #include "config.h"
 #include "health.h"
 
+#if MG_ENABLE_HEALTH
+#if MG_ARCH == MG_ARCH_ESP32
+// reusable for other platforms, currently ESP32-only
+struct mg_health_coredump {
+  const void *ptr;
+  size_t poffset;
+  size_t size;
+};
+
+static struct mg_health_coredump s_coredump;
+#endif
+
+bool mg_health_coredump_begin(size_t *size) {
+#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+  const esp_partition_t *p = esp_partition_find_first(
+      ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_COREDUMP, NULL);
+  size_t address = 0, len = 0;
+  esp_err_t err = esp_core_dump_image_get(&address, &len);
+  if (size == NULL || s_coredump.ptr != NULL || err != ESP_OK || p == NULL)
+    return false;
+  s_coredump.ptr = p;
+  s_coredump.poffset = address - p->address;
+  s_coredump.size = len;
+  *size = len;
+  return true;
+#else
+  (void) size;
+  return false;
+#endif
+}
+
+bool mg_health_coredump_read(size_t offset, void *buf, size_t *len) {
+#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+  const esp_partition_t *p = (const esp_partition_t *) s_coredump.ptr;
+  if (p == NULL || offset > s_coredump.size)
+    return false;
+  if (*len > s_coredump.size - offset) *len = s_coredump.size - offset;
+  return esp_partition_read(p, s_coredump.poffset + offset, buf, *len) == ESP_OK;
+#else
+  (void) offset, (void) buf, (void) len;
+  return false;
+#endif
+}
+
+bool mg_health_coredump_end(void) {
+#if MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+  bool ok = s_coredump.ptr != NULL;
+  memset(&s_coredump, 0, sizeof(s_coredump));
+  return ok;
+#else
+  return false;
+#endif
+}
+
 // The one health record. Lives in RAM that survives a warm reset, see
 // MG_HEALTH_RAM and the .mg_health region in the linker script
 struct mg_health mg_health_record MG_HEALTH_RAM;
 
-// STM32 H723 support. Needs the _estack symbol from the linker script
-#if MG_ENABLE_HEALTH && (defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5))
+// STM32 H7, H5, C5 support. Needs the _estack symbol from the linker script
+#if defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5)
 // Fault handler body. Runs in exception context: no printf, no malloc, no
 // blocking calls. Copies the unwind registers and raw stack into the health
 // record, then resets.
@@ -48,52 +102,57 @@ void BusFault_Handler(void) __attribute__((alias("HardFault_Handler")));
 void UsageFault_Handler(void) __attribute__((alias("HardFault_Handler")));
 #endif
 
-// Start a new boot: validate the record, count the boot, store the reset
-// reason. The current boot moves to prev_* slots first, so the previous
-// boot's uptime and reason stay readable. Called by MG_HEALTH_INIT()
+// Start a new boot: validate the record. Called by MG_HEALTH_INIT()
 void mg_health_init(void) {
   char magic[] = MG_HEALTH_MAGIC;
-  // struct mg_health *h = mg_health_get();
   if (!mg_health_valid()) {  // First boot, or RAM lost its contents
     memset(&mg_health_record, 0, sizeof(mg_health_record));
     memcpy(mg_health_record.magic, magic, sizeof(mg_health_record.magic));
   }
-
-#if 0 && MG_ARCH == MG_ARCH_ESP32 && CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
-  {
+#if MG_ARCH == MG_ARCH_ESP32
+#if CONFIG_IDF_TARGET_ARCH_XTENSA
+  mg_health_record.arch = (uint16_t) MG_HEALTH_ARCH_XTENSA;
+#elif CONFIG_IDF_TARGET_ARCH_RISCV
+  mg_health_record.arch = (uint16_t) MG_HEALTH_ARCH_RISCV;
+#endif
+  esp_reset_reason_t rr = esp_reset_reason();
+  mg_health_record.reset_reason = esp2mg(rr);
+#if CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH == 0
+  MG_ERROR(("MG_HEALTH is enabled but CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH=n"));
+#else
     // After a crash, copy the backtrace from the core dump in flash: the same
     // addresses the panic handler prints as "Backtrace: PC:SP PC:SP ...".
     // The core dump stays in flash, so check the reset reason, otherwise an
     // old crash is reported on every boot
-    static esp_core_dump_summary_t s;  // Big on RISC-V, keep it off the stack
-    esp_reset_reason_t rr = esp_reset_reason();
+    esp_core_dump_summary_t *s = calloc(1, sizeof(*s));
     uint32_t *out = mg_health_record.data;
-    size_t n = 0, max = MG_HEALTH_DATA_SIZE;
-    if (rr != ESP_RST_PANIC && rr != ESP_RST_INT_WDT && rr != ESP_RST_TASK_WDT)
-      return;  // Not a crash that went through the panic handler
-    if (max == 0 || esp_core_dump_get_summary(&s) != ESP_OK) return;
-
-    mg_health_record.cpuid = 42;  // ESP32
-    mg_health_record.reset_reason = MG_HEALTH_RESET_FAULT;
-
+    size_t n = 0;
     memset(out, 0, sizeof(mg_health_record.data));
-    out[n++] = s.exc_pc;
+    if (s == NULL) return;
+    if ((rr != ESP_RST_PANIC && rr != ESP_RST_INT_WDT &&
+         rr != ESP_RST_TASK_WDT)  // Not a crash caught by the panic handler
+        || esp_core_dump_get_summary(s) != ESP_OK) {
+      free(s);
+      return;
+    }
+    out[n++] = s->exc_pc;
+    memcpy(&out[n], s->exc_task, 16), n += 4;
 #if CONFIG_IDF_TARGET_ARCH_XTENSA
-    for (uint32_t i = 0; i < s.exc_bt_info.depth && n < max; i++) {
-      if (s.exc_bt_info.bt[i] != s.exc_pc) out[n++] = s.exc_bt_info.bt[i];
-    }
+    out[n++] = s->ex_info.exc_a[0];
+    out[n++] = s->ex_info.exc_a[1];
+    size_t len = s->exc_bt_info.depth;
+    if (len > MG_HEALTH_DATA_SIZE - n) len = (MG_HEALTH_DATA_SIZE - n);
+    memcpy(&out[n], s->exc_bt_info.bt, 4 * len); // sizeof(uint32_t)
 #elif CONFIG_IDF_TARGET_ARCH_RISCV
-    // No unwinder: take the return address, then words on the stack that
-    // point into executable memory (a heuristic, may include stale values)
-    if (n < max) out[n++] = s.ex_info.ra;
-    for (uint32_t i = 0; i + 4 <= s.exc_bt_info.dump_size && n < max; i += 4) {
-      uint32_t w;
-      memcpy(&w, &s.exc_bt_info.stackdump[i], sizeof(w));  // Byte array
-      if (esp_ptr_executable((void *) (uintptr_t) w)) out[n++] = w;
-    }
-#endif
-  }
+    out[n++] = s->ex_info.exc_ra;
+    out[n++] = s->ex_info.exc_sp;
+    size_t len = s->exc_bt_info.dump_size / 4 ; // sizeof(uint32_t)
+    if (len > MG_HEALTH_DATA_SIZE - n) len = (MG_HEALTH_DATA_SIZE - n);
+    memcpy(&out[n], s->exc_bt_info.stackdump, 4 * len);
 #endif
+    free(s);
+#endif  // CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+#endif  // MG_ARCH_ESP32
 }
 
 static size_t print_uint32(void (*fn)(char, void *), void *arg, va_list *ap) {
@@ -107,11 +166,17 @@ static size_t print_uint32(void (*fn)(char, void *), void *arg, va_list *ap) {
 size_t mg_print_crash_record(void (*fn)(char, void *), void *arg, va_list *ap) {
   size_t len = 0;
   if (mg_health_valid() &&
-      mg_health_record.reset_reason == MG_HEALTH_RESET_FAULT) {
+      (mg_health_record.reset_reason == (uint16_t) MG_HEALTH_RESET_FAULT
+#if MG_ARCH == MG_ARCH_ESP32
+       || mg_health_record.reset_reason == (uint16_t) MG_HEALTH_RESET_WATCHDOG
+#endif
+       )) {
     size_t n = sizeof(mg_health_record.data) / sizeof(mg_health_record.data[0]);
-    len += mg_xprintf(fn, arg, "{%m:%hhu,%m:%u,%m:[%M]}",            //
-                      MG_ESC("version"), mg_health_record.magic[3],  //
-                      MG_ESC("cpuid"), mg_health_record.cpuid,       //
+    len += mg_xprintf(fn, arg, "{%m:%hhu,%m:%hu,%m:%hu,%m:%u,%m:[%M]}",  //
+                      MG_ESC("version"), mg_health_record.magic[3],      //
+                      MG_ESC("arch"), mg_health_record.arch,             //
+                      MG_ESC("reason"), mg_health_record.reset_reason,   //
+                      MG_ESC("cpuid"), mg_health_record.cpuid,           //
                       MG_ESC("data"), print_uint32, n, mg_health_record.data);
   } else {
     len += mg_xprintf(fn, arg, "{}");
@@ -119,3 +184,4 @@ size_t mg_print_crash_record(void (*fn)(char, void *), void *arg, va_list *ap) {
   (void) ap;
   return len;
 }
+#endif

src/health.h

@@ -5,6 +5,8 @@
 #include "arch.h"
 #include "printf.h"
 
+#if MG_ENABLE_HEALTH
+
 #ifndef MG_HEALTH_MAGIC
 #define MG_HEALTH_MAGIC {'M', 'G', 'H', '3'}  // '3' is the layout version
 #endif
@@ -13,13 +15,15 @@
 #define MG_HEALTH_RAM __attribute__((section(".mg_health")))
 #endif
 
-#if !defined(MG_HEALTH_DATA_SIZE) && (defined(STM32H7_DEV_ID) || defined(STM32H5) || defined(STM32C5))
-#define MG_HEALTH_DATA_SIZE 250
-#endif
-
 #ifndef MG_HEALTH_DATA_SIZE
+#if (defined(STM32H7_DEV_ID) || defined(STM32H5)) || defined(STM32C5)
+#define MG_HEALTH_DATA_SIZE 250
+#elif MG_ARCH == MG_ARCH_ESP32
+#define MG_HEALTH_DATA_SIZE 23
+#else
 #define MG_HEALTH_DATA_SIZE 10
 #endif
+#endif  // MG_HEALTH_DATA_SIZE
 
 // Places the record in RAM that survives a reset. Define in mongoose_config.h
 // to match the linker script, e.g. __attribute__((section(".mg_health")))
@@ -27,6 +31,13 @@
 #define MG_HEALTH_RAM
 #endif
 
+// CPU core architecture
+enum mg_health_arch {
+  MG_HEALTH_ARCH_ARM = 0,
+  MG_HEALTH_ARCH_XTENSA,
+  MG_HEALTH_ARCH_RISCV
+};
+
 // Why the device restarted. Hardware usually reports several flags at once,
 // so these are ordered by how much they tell you: the most specific cause a
 // device reports wins
@@ -43,7 +54,8 @@ enum mg_health_reason {
 
 struct mg_health {
   char magic[4];          // MG_HEALTH_MAGIC when the record holds valid data
-  uint32_t reset_reason;  // enum mg_health_reason that started this boot
+  uint16_t reset_reason;  // enum mg_health_reason that started this boot
+  uint16_t arch;          // enum mg_health_arch, core architecture (ARM, etc)
   uint32_t cpuid;         // ARM CPU ID
   uint32_t data[MG_HEALTH_DATA_SIZE];
 };
@@ -76,6 +88,69 @@ static inline const char *mg_health_reason_str(int reason) {
   }
 }
 
+#if MG_ARCH == MG_ARCH_ESP32
+#ifndef CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH
+#define CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH 0
+#endif
+#ifndef ESP_PARTITION_SUBTYPE_DATA_COREDUMP
+#define ESP_PARTITION_SUBTYPE_DATA_COREDUMP 0x03
+#endif
+// clang-format off
+static inline uint16_t esp2mg(esp_reset_reason_t rr) {
+  switch(rr) {
+    case ESP_RST_POWERON: return (uint16_t) MG_HEALTH_RESET_POWER;
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 2)
+    case ESP_RST_PWR_GLITCH:
+#endif
+    case ESP_RST_BROWNOUT: return (uint16_t) MG_HEALTH_RESET_BROWNOUT;
+    case ESP_RST_EXT: return (uint16_t) MG_HEALTH_RESET_PIN;
+    case ESP_RST_SW: return (uint16_t) MG_HEALTH_RESET_SOFTWARE;
+    case ESP_RST_DEEPSLEEP: return (uint16_t) MG_HEALTH_RESET_LOWPOWER;
+    case ESP_RST_INT_WDT:
+    case ESP_RST_TASK_WDT:
+    case ESP_RST_WDT: return (uint16_t) MG_HEALTH_RESET_WATCHDOG;
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 2, 2)
+    case ESP_RST_CPU_LOCKUP:
+#endif
+    case ESP_RST_PANIC: return (uint16_t) MG_HEALTH_RESET_FAULT;
+    default: break;
+  }
+  return (uint16_t) MG_HEALTH_RESET_UNKNOWN;
+}
+// clang-format on
+#endif
+
 #define MG_HEALTH_INIT() mg_health_init()
 extern size_t mg_print_crash_record(mg_pfn_t, void *, va_list *);
 extern void mg_health_init(void);
+extern bool mg_health_coredump_begin(size_t *size);
+extern bool mg_health_coredump_read(size_t offset, void *buf, size_t *len);
+extern bool mg_health_coredump_end(void);
+#else
+#define MG_HEALTH_INIT()
+static inline int mg_health_reason(void) {
+  return 0;
+}
+static inline const char *mg_health_reason_str(int reason) {
+  (void) reason;
+  return "unknown";
+}
+static inline size_t mg_print_crash_record(mg_pfn_t fn, void *arg,
+                                           va_list *ap) {
+  (void) ap;
+  return mg_xprintf(fn, arg, "{}");
+}
+static inline bool mg_health_coredump_begin(size_t *size) {
+  (void) size;
+  return false;
+}
+static inline bool mg_health_coredump_read(size_t offset, void *buf,
+                                           size_t *len) {
+  (void) offset, (void) buf, (void) len;
+  return false;
+}
+static inline bool mg_health_coredump_end(void) {
+  return false;
+}
+
+#endif

src/mdash.c

@@ -89,6 +89,7 @@ static void mg_mdash_fn(struct mg_connection *c, int ev, void *ev_data) {
     }
     mg_iobuf_free(&io);
   } else if (ev == MG_EV_CLOSE) {
+    mg_health_coredump_end();
     mg_mdash_conn = NULL;
     MG_INFO(("disconnected, ram %lu", 0));
   }
@@ -146,6 +147,35 @@ static void mg_mdash_rpc_ota_end(struct mg_rpc_req *r) {
   // MG_ESC("percent"));
 }
 
+static void rpc_coredump_begin(struct mg_rpc_req *r) {
+  size_t size = 0;
+  if (mg_health_coredump_begin(&size)) {
+    mg_rpc_ok(r, "{%m:%llu}", MG_ESC("size"), (uint64_t) size);
+  } else {
+    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
+  }
+}
+
+static void rpc_coredump_read(struct mg_rpc_req *r) {
+  uint8_t buf[768];
+  size_t len = sizeof(buf);
+  size_t offset = (size_t) mg_json_get_long(r->frame, "$.params.offset", -1);
+  if (mg_health_coredump_read(offset, buf, &len)) {
+    mg_rpc_ok(r, "{%m:\"%M\"}", MG_ESC("data"), mg_print_base64,
+              (int) len, buf);
+  } else {
+    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
+  }
+}
+
+static void rpc_coredump_end(struct mg_rpc_req *r) {
+  if (mg_health_coredump_end()) {
+    mg_rpc_ok(r, "true");
+  } else {
+    mg_rpc_err(r, 500, "%m", MG_ESC("failed"));
+  }
+}
+
 void mg_mdash_init(struct mg_mgr *mgr) {
   MG_INFO(("Initialising mdash agent, key [%s]", MG_MDASH_KEY));
   mg_rpc_add(&mgr->rpcs, mg_str("RPC.List"), mg_rpc_list, NULL);
@@ -153,6 +183,9 @@ void mg_mdash_init(struct mg_mgr *mgr) {
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.Begin"), mg_mdash_rpc_ota_begin, NULL);
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.Write"), mg_mdash_rpc_ota_write, NULL);
   mg_rpc_add(&mgr->rpcs, mg_str("OTA.End"), mg_mdash_rpc_ota_end, NULL);
+  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.Begin"), rpc_coredump_begin, NULL);
+  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.Read"), rpc_coredump_read, NULL);
+  mg_rpc_add(&mgr->rpcs, mg_str("CoreDump.End"), rpc_coredump_end, NULL);
 }
 
 void mg_mdash_poll(struct mg_mgr *mgr) {

tutorials/esp32/minimal/main/main.c

@@ -65,8 +65,10 @@ static void http_ev_handler(struct mg_connection *c, int ev, void *ev_data) {
   }
 }
 
+extern void wifi_init(const char *ssid, const char *pass);
+
 void app_main(void) {
-  void wifi_init(const char *ssid, const char *pass);
+  MG_HEALTH_INIT();
   wifi_init(WIFI_SSID, WIFI_PASS);
 
   struct mg_mgr mgr;

tutorials/esp32/minimal/main/mongoose_config.h

@@ -1,4 +1,6 @@
 #define MG_ARCH MG_ARCH_ESP32
 
+#define MG_ENABLE_HEALTH 1
+
 #define MG_TLS MG_TLS_BUILTIN
 //#define MG_TLS MG_TLS_MBED