Stabelized OTA Update with Retries

main/ota_uart.c

@@ -12,6 +12,7 @@ typedef struct {
   uint32_t total_size;
   uint32_t received;
   uint32_t written;
+  uint32_t expected_seq;
   int target_slot;
   uint8_t block_buf[OTA_UART_FLASH_BLOCK_SIZE];
   size_t block_len;
@@ -112,10 +113,30 @@ int ota_uart_prepare(uint32_t total_size) {
   return s_ota.target_slot;
 }
 
-ota_feed_result_t ota_uart_feed(const uint8_t *data, size_t len) {
+bool ota_uart_block_ready_for_reack(void) {
+  if (!s_ota.active) {
+    return false;
+  }
+  return s_ota.written > 0 &&
+         (s_ota.written % OTA_UART_FLASH_BLOCK_SIZE) == 0 &&
+         s_ota.block_len == 0;
+}
+
+ota_feed_result_t ota_uart_feed_chunk(uint32_t seq, const uint8_t *data,
+                                      size_t len) {
   if (!s_ota.active || data == NULL || len == 0) {
     return OTA_FEED_ERROR;
   }
+  if (seq < s_ota.expected_seq) {
+    return OTA_FEED_SEQ_DUP;
+  }
+  if (seq > s_ota.expected_seq) {
+    ESP_LOGW(TAG, "seq gap: got %lu expected %lu", (unsigned long)seq,
+             (unsigned long)s_ota.expected_seq);
+    return OTA_FEED_SEQ_GAP;
+  }
+  s_ota.expected_seq++;
+
   if (len > OTA_UART_HOST_CHUNK_SIZE) {
     ESP_LOGW(TAG, "chunk %u > %u, truncating", (unsigned)len,
              OTA_UART_HOST_CHUNK_SIZE);
@@ -200,6 +221,13 @@ esp_err_t ota_uart_finish(bool set_boot, bool *success_out) {
     return err;
   }
 
+  if (s_ota.total_size > 0 && s_ota.received != s_ota.total_size) {
+    ESP_LOGE(TAG, "size mismatch: received=%lu expected=%lu",
+             (unsigned long)s_ota.received, (unsigned long)s_ota.total_size);
+    ota_uart_abort();
+    return ESP_ERR_INVALID_SIZE;
+  }
+
   err = esp_ota_end(s_ota.handle);
   if (err != ESP_OK) {
     ESP_LOGE(TAG, "esp_ota_end failed: %s", esp_err_to_name(err));