feat(at): add UART baud AT commands

AT固件使用手册.md

@@ -143,6 +143,12 @@ UART 记号约定：
 - `U0 = USART2`
 - `U1 = USART3`
 
+### 7.4 BAUD 默认值
+
+```text
+BAUD = U0,115200 / U1,115200
+```
+
 ## 8. AT 命令定义
 
 ### 8.1 测试设备在线
@@ -239,7 +245,45 @@ OK
 
 当MAC设置为全0时，固件将使用硬件MAC地址，此时通过AT+?查询到的MAC地址即为当前生效的硬件MAC地址。
 
-### 8.5 LINK 类命令
+### 8.5 BAUD 类命令
+
+#### 查询 UART 波特率
+
+```text
+AT+BAUD?\r\n
+```
+
+返回示例：
+
+```text
++BAUD:U0=115200,U1=115200
+OK
+```
+
+#### 设置 UART 波特率
+
+```text
+AT+BAUD=U0,115200\r\n
+AT+BAUD=U1,38400\r\n
+```
+
+字段顺序：
+
+```text
+UART,BAUDRATE
+```
+
+字段说明：
+
+- `UART`：`U0/U1`
+- `BAUDRATE`：范围 `1200~921600`
+
+说明：
+
+- 该命令只更新当前运行配置记录，不会立即重初始化 `USART2/USART3`
+- 执行 `AT+SAVE` 后再执行 `AT+RESET`，重启时按保存值生效
+
+### 8.6 LINK 类命令
 
 #### 设置单条 LINK 记录
 

App/config.c

@@ -365,8 +365,8 @@ static at_result_t handle_summary_query(char *response, uint16_t max_len)
              g_config.links[2].enabled, g_config.links[2].local_port, rip_str[2], g_config.links[2].remote_port, link_uart_to_str(g_config.links[2].uart),
              g_config.links[3].enabled, g_config.links[3].local_port, rip_str[3], g_config.links[3].remote_port, link_uart_to_str(g_config.links[3].uart),
              g_config.mux_mode,
-             g_config.uart_baudrate[0],
+             (unsigned long)g_config.uart_baudrate[0],
-             g_config.uart_baudrate[1]);
+             (unsigned long)g_config.uart_baudrate[1]);
 
     return AT_OK;
 }
@@ -386,6 +386,16 @@ static at_result_t handle_net_query(char *response, uint16_t max_len)
     return AT_OK;
 }
 
+static at_result_t handle_baud_query(char *response, uint16_t max_len)
+{
+    snprintf(response,
+             max_len,
+             "+BAUD:U0=%lu,U1=%lu\r\nOK\r\n",
+             (unsigned long)g_config.uart_baudrate[0],
+             (unsigned long)g_config.uart_baudrate[1]);
+    return AT_OK;
+}
+
 static at_result_t handle_link_query(uint32_t index, char *response, uint16_t max_len)
 {
     char rip_str[16];
@@ -556,6 +566,38 @@ at_result_t config_process_at_cmd(const char *cmd, char *response, uint16_t max_
         snprintf(response, max_len, "OK\r\n");
         return AT_NEED_REBOOT;
     }
+    if (equals_ignore_case(p, "BAUD?")) {
+        return handle_baud_query(response, max_len);
+    }
+    if (parse_command_with_value(p, "BAUD", &value)) {
+        char value_copy[32];
+        char *cursor;
+        char *token;
+        uint8_t uart;
+        uint32_t baudrate;
+
+        strncpy(value_copy, value, sizeof(value_copy) - 1u);
+        value_copy[sizeof(value_copy) - 1u] = '\0';
+        cursor = value_copy;
+
+        token = config_next_token(&cursor);
+        if (token == NULL || parse_link_uart(token, &uart) != 0) {
+            snprintf(response, max_len, "ERROR: Invalid route field\r\n");
+            return AT_INVALID_PARAM;
+        }
+        token = config_next_token(&cursor);
+        if (token == NULL || parse_u32_value(token, 1200u, 921600u, &baudrate) != 0) {
+            snprintf(response, max_len, "ERROR: Invalid baudrate\r\n");
+            return AT_INVALID_PARAM;
+        }
+        if (config_next_token(&cursor) != NULL) {
+            snprintf(response, max_len, "ERROR: Invalid value\r\n");
+            return AT_INVALID_PARAM;
+        }
+
+        g_config.uart_baudrate[uart] = baudrate;
+        return handle_baud_query(response, max_len) == AT_OK ? AT_NEED_REBOOT : AT_ERROR;
+    }
     if (equals_ignore_case(p, "NET?")) {
         return handle_net_query(response, max_len);
     }