STM32F OTA support

cesanta · Oct 30, 2024 · a3358f3 · a3358f3
1 parent d3ffe8c
commit a3358f3
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Showing 4 changed files with 453 additions and 0 deletions.
diff --git a/mongoose.c b/mongoose.c
@@ -6042,6 +6042,233 @@ bool mg_ota_end(void) {
 }
 #endif
 
+#ifdef MG_ENABLE_LINES
+#line 1 "src/ota_stm32f.c"
+#endif
+
+
+
+
+#if MG_OTA == MG_OTA_STM32F
+
+static bool mg_stm32f_write(void *, const void *, size_t);
+static bool mg_stm32f_swap(void);
+
+static struct mg_flash s_mg_flash_stm32f = {
+    (void *) 0x08000000,  // Start
+    0,                    // Size, FLASH_SIZE_REG
+    0,                    // Irregular sector size
+    32,                   // Align, 256 bit
+    mg_stm32f_write,
+    mg_stm32f_swap,
+};
+
+#define FLASH_BASE 0x40023c00  // Base address for bank1
+#define FLASH_KEYR 0x04
+#define FLASH_SR 0x0c
+#define FLASH_CR 0x10
+#define FLASH_OPTCR 0x14
+#define FLASH_SIZE_REG_F7 0x1FF0F442
+#define FLASH_SIZE_REG_F4 0x1FFF7A22
+
+#define STM_DBGMCU_IDCODE 0xE0042000
+#define STM_DEV_ID (MG_REG(STM_DBGMCU_IDCODE) & (MG_BIT(12) - 1))
+#define SYSCFG_MEMRMP 0x40013800
+
+#define FLASH_SIZE_REG_LOCATION \
+    ((STM_DEV_ID >= 0x449) ? FLASH_SIZE_REG_F7 : FLASH_SIZE_REG_F4)
+
+static size_t flash_size(void) {
+  return (MG_REG(FLASH_SIZE_REG_LOCATION) & 0xFFFF) * 1024;
+}
+
+MG_IRAM static int is_dualbank(void) {
+  // only F42x/F43x series (0x419) support dual bank
+  return STM_DEV_ID == 0x419;
+}
+
+MG_IRAM static void flash_unlock(void) {
+  static bool unlocked = false;
+  if (unlocked == false) {
+    MG_REG(FLASH_BASE + FLASH_KEYR) = 0x45670123;
+    MG_REG(FLASH_BASE + FLASH_KEYR) = 0xcdef89ab;
+    unlocked = true;
+  }
+}
+
+#define FLASH_CONFIG_16_64_128 1 // used by STM32F7
+#define FLASH_CONFIG_32_128_256 2 // used by STM32F4 and F2
+
+MG_IRAM static bool flash_page_start(volatile uint32_t *dst) {
+  char *base = (char *) s_mg_flash_stm32f.start;
+  char *end = base + s_mg_flash_stm32f.size;
+
+  if (is_dualbank() && dst >= (uint32_t *) (base + (end - base) / 2)) {
+    dst = (uint32_t*)((uint32_t)dst - (end - base) / 2);
+  }
+
+  uint32_t flash_config = FLASH_CONFIG_16_64_128;
+  if (STM_DEV_ID >= 0x449) {
+    flash_config = FLASH_CONFIG_32_128_256;
+  }
+
+  volatile char *p = (char *) dst;
+  if (p >= base && p < end) {
+    if (p < base + 16 * 1024 * 4 * flash_config) {
+      if ((p - base) % (16 * 1024 * flash_config) == 0) return true;
+    } else if (p == base + 16 * 1024 * 4 * flash_config) {
+      return true;
+    } else if ((p - base) % (128 * 1024 * flash_config) == 0) return true;
+  }
+  return false;
+}
+
+MG_IRAM static int flash_sector(volatile uint32_t *addr) {
+  char *base = (char *) s_mg_flash_stm32f.start;
+  char *end = base + s_mg_flash_stm32f.size;
+  bool addr_in_bank_2 = false;
+  if (is_dualbank() && addr >= (uint32_t *) (base + (end - base) / 2)) {
+    addr = (uint32_t*)((uint32_t)addr - (end - base) / 2);
+    addr_in_bank_2 = true;
+  }
+  volatile char *p = (char *) addr;
+  uint32_t flash_config = FLASH_CONFIG_16_64_128;
+  if (STM_DEV_ID >= 0x449) {
+    flash_config = FLASH_CONFIG_32_128_256;
+  }
+  int sector = -1;
+  if (p >= base && p < end) {
+    if (p < base + 16 * 1024 * 4 * flash_config) {
+      sector =  (p - base) / (16 * 1024 * flash_config);
+    } else if (p >= base + 64 * 1024 * flash_config &&
+              p < base + 128 * 1024 * flash_config) {
+      sector = 4;
+    } else {
+      sector = (p - base) / (128 * 1024 * flash_config) + 4;
+    }
+  }
+  if (sector == -1) return -1;
+  if (addr_in_bank_2) sector += 12; // a bank has 12 sectors
+  return sector;
+}
+
+MG_IRAM static bool flash_is_err() {
+  return MG_REG(FLASH_BASE + FLASH_SR) & ((MG_BIT(7) - 1) << 1);
+}
+
+MG_IRAM static void flash_wait() {
+  while (MG_REG(FLASH_BASE + FLASH_SR) & (MG_BIT(16))) (void) 0;
+}
+
+MG_IRAM static void flash_clear_err() {
+  flash_wait(); // Wait until ready
+  MG_REG(FLASH_BASE + FLASH_SR) = 0xf2;  // Clear all errors
+}
+
+MG_IRAM static bool mg_stm32f_erase(void *addr) {
+  bool ok = false;
+  if (flash_page_start(addr) == false) {
+    MG_ERROR(("%p is not on a sector boundary", addr));
+  } else {
+    int sector = flash_sector(addr);
+    if (sector < 0) return false;
+    uint32_t sector_reg = sector;
+    if (is_dualbank() && sector >= 12) {
+      // 3.9.8 Flash control register (FLASH_CR) for F42xxx and F43xxx
+      // BITS[7:3]
+      sector_reg -= 12;
+      sector_reg |= MG_BIT(4);
+    }
+    flash_unlock();
+    flash_wait();
+    uint32_t cr = MG_BIT(1); // SER
+    cr |= MG_BIT(16); // STRT
+    cr |= (sector_reg & 31) << 3; // sector
+    MG_REG(FLASH_BASE + FLASH_CR) = cr;
+    ok = !flash_is_err();
+    MG_DEBUG(("Erase sector %lu @ %p %s. CR %#lx SR %#lx", sector, addr,
+              ok ? "ok" : "fail", MG_REG(FLASH_BASE + FLASH_CR),
+              MG_REG(FLASH_BASE + FLASH_SR)));
+    // After we have erased the sector, set CR flags for programming
+    // 2 << 8 is word write parallelism, bit(0) is PG. RM0385, section 3.7.5
+    MG_REG(FLASH_BASE + FLASH_CR) = MG_BIT(0) | (2 << 8);
+    flash_clear_err();
+  }
+  return ok;
+}
+
+MG_IRAM static bool mg_stm32f_swap(void) {
+  // STM32 F42x/F43x support dual bank, however, the memory mapping
+  // change will not be carried through a hard reset. Therefore, we will use
+  // the single bank approach for this family as well.
+  return true;
+}
+
+static bool s_flash_irq_disabled;
+
+MG_IRAM static bool mg_stm32f_write(void *addr, const void *buf, size_t len) {
+  if ((len % s_mg_flash_stm32f.align) != 0) {
+    MG_ERROR(("%lu is not aligned to %lu", len, s_mg_flash_stm32f.align));
+    return false;
+  }
+  uint32_t *dst = (uint32_t *) addr;
+  uint32_t *src = (uint32_t *) buf;
+  uint32_t *end = (uint32_t *) ((char *) buf + len);
+  bool ok = true;
+  MG_ARM_DISABLE_IRQ();
+  flash_unlock();
+  flash_clear_err();
+  MG_REG(FLASH_BASE + FLASH_CR) = MG_BIT(0) | MG_BIT(9);   // PG, 32-bit
+  flash_wait();
+  MG_DEBUG(("Writing flash @ %p, %lu bytes", addr, len));
+  while (ok && src < end) {
+    if (flash_page_start(dst) && mg_stm32f_erase(dst) == false) break;
+    *(volatile uint32_t *) dst++ = *src++;
+    MG_DSB(); // ensure flash is written with no errors
+    flash_wait();
+    if (flash_is_err()) ok = false;
+  }
+  if (!s_flash_irq_disabled) MG_ARM_ENABLE_IRQ();
+  MG_DEBUG(("Flash write %lu bytes @ %p: %s. CR %#lx SR %#lx", len, dst,
+            ok ? "ok" : "fail", MG_REG(FLASH_BASE + FLASH_CR),
+            MG_REG(FLASH_BASE + FLASH_SR)));
+  MG_REG(FLASH_BASE + FLASH_CR) &= ~MG_BIT(0);  // Clear programming flag
+  return ok;
+}
+
+MG_IRAM void single_bank_swap(void) {
+  // TODO(): actually swap firmwares when needed
+  char *base = (char *) s_mg_flash_stm32f.start;
+  char *p2 = base + s_mg_flash_stm32f.size / 2;
+  mg_stm32f_write(base, p2, s_mg_flash_stm32f.size / 2);
+  *(volatile unsigned long *) 0xe000ed0c = 0x5fa0004;
+}
+
+
+bool mg_ota_begin(size_t new_firmware_size) {
+  s_mg_flash_stm32f.size = flash_size();
+  return mg_ota_flash_begin(new_firmware_size, &s_mg_flash_stm32f);
+}
+
+bool mg_ota_write(const void *buf, size_t len) {
+  return mg_ota_flash_write(buf, len, &s_mg_flash_stm32f);
+}
+
+bool mg_ota_end(void) {
+  if (mg_ota_flash_end(&s_mg_flash_stm32f)) {
+     // Swap partitions. Pray power does not go away
+    MG_INFO(("Swapping partitions, size %u (%u sectors)",
+              s_mg_flash_stm32f.size, STM_DEV_ID == 0x449 ? 8 : 12));
+    MG_INFO(("Do NOT power off..."));
+    mg_log_level = MG_LL_NONE;
+    s_flash_irq_disabled = true;
+    // Runs in RAM, will reset when finished
+    single_bank_swap();
+  }
+  return false;
+}
+#endif
+
 #ifdef MG_ENABLE_LINES
 #line 1 "src/ota_stm32h5.c"
 #endif

diff --git a/mongoose.h b/mongoose.h
@@ -2643,6 +2643,7 @@ void mg_rpc_list(struct mg_rpc_req *r);
 #define MG_OTA_NONE 0       // No OTA support
 #define MG_OTA_STM32H5 1    // STM32 H5
 #define MG_OTA_STM32H7 2    // STM32 H7
+#define MG_OTA_STM32F  3    // STM32 F7/F4/F2
 #define MG_OTA_CH32V307 100 // WCH CH32V307
 #define MG_OTA_U2A 200      // Renesas U2A16, U2A8, U2A6
 #define MG_OTA_RT1020 300   // IMXRT1020
@@ -2670,6 +2671,7 @@ bool mg_ota_write(const void *buf, size_t len);  // Write chunk, aligned to 1k
 bool mg_ota_end(void);                           // Stop writing
 
 
+
 #if MG_OTA != MG_OTA_NONE && MG_OTA != MG_OTA_CUSTOM
 
 struct mg_flash {

diff --git a/src/ota.h b/src/ota.h
@@ -8,6 +8,7 @@
 #define MG_OTA_NONE 0       // No OTA support
 #define MG_OTA_STM32H5 1    // STM32 H5
 #define MG_OTA_STM32H7 2    // STM32 H7
+#define MG_OTA_STM32F  3    // STM32 F7/F4/F2
 #define MG_OTA_CH32V307 100 // WCH CH32V307
 #define MG_OTA_U2A 200      // Renesas U2A16, U2A8, U2A6
 #define MG_OTA_RT1020 300   // IMXRT1020