gdbstub:support only use gdbstub when panic

Signed-off-by: anjiahao <anjiahao@xiaomi.com>

drivers/serial/Kconfig

@@ -53,6 +53,23 @@ config SERIAL_GDBSTUB_PATH
 	---help---
 		The path to the serial device that will be used for GDB stub.
 
+config SERIAL_GDBSTUB_AUTO_ATTACH
+	bool "GDBSTUB Serial Auto attach"
+	depends on SERIAL_GDBSTUB
+	default n
+	---help---
+		Attach the serial port to gdbstub by default.
+		Will cover the GDBSTUB_SERIAL_PATH, that port will only
+		be used for GDB stub.
+
+config SERIAL_GDBSTUB_PANIC_TIMEOUT
+	int "GDBSTUB Serial panic timeout"
+	depends on SERIAL_GDBSTUB
+	default 10
+	---help---
+		Delay the panic timeout for gdbstub to connect.
+		0 will disable the timeout.
+
 config UART_HOSTFS
 	bool "Use hostfs read/write on UART_HOSTFS_DEVPATH as uart console"
 	depends on FS_HOSTFS

drivers/serial/serial.c

@@ -1928,9 +1928,11 @@ int uart_register(FAR const char *path, FAR uart_dev_t *dev)
   /* Register the serial driver */
 
 #ifdef CONFIG_SERIAL_GDBSTUB
-  if (strcmp(path, CONFIG_SERIAL_GDBSTUB_PATH) == 0)
+  if (uart_gdbstub_register(dev, path) == 0)
     {
-      return uart_gdbstub_register(dev);
+      /* No need register the device if it is used by gdbstub */
+
+      return 0;
     }
 #endif
 

drivers/serial/serial_gdbstub.c

@@ -24,6 +24,7 @@
 
 #include <nuttx/serial/serial.h>
 #include <nuttx/panic_notifier.h>
+#include <nuttx/syslog/syslog.h>
 #include <nuttx/kmalloc.h>
 #include <nuttx/gdbstub.h>
 #include <nuttx/nuttx.h>
@@ -32,24 +33,54 @@
 #include <debug.h>
 
 /****************************************************************************
- * Private Data
+ * Private Types
  ****************************************************************************/
 
 struct uart_gdbstub_s
 {
   FAR struct uart_dev_s *dev;
+  FAR struct uart_dev_s *console;
   FAR struct gdb_state_s *state;
   FAR const struct uart_ops_s *org_ops;
   struct uart_ops_s ops;
   struct notifier_block nb;
 };
 
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
 static FAR struct uart_gdbstub_s *g_uart_gdbstub;
 
+/****************************************************************************
+ * Private Functions prototypes
+ ****************************************************************************/
+
+static int uart_gdbstub_ctrlc(FAR struct uart_dev_s *dev,
+                              FAR unsigned int *status);
+
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
 
+static void uart_gdbstub_attach(FAR struct uart_gdbstub_s *uart_gdbstub,
+                                bool replace)
+{
+  FAR uart_dev_t *dev = uart_gdbstub->dev;
+
+  if (replace && uart_gdbstub->org_ops == NULL)
+    {
+      memcpy(&uart_gdbstub->ops, dev->ops, sizeof(struct uart_ops_s));
+      uart_gdbstub->org_ops = dev->ops;
+      uart_gdbstub->ops.receive = uart_gdbstub_ctrlc;
+      dev->ops = &uart_gdbstub->ops;
+    }
+
+  uart_setup(dev);
+  uart_attach(dev);
+  uart_enablerxint(dev);
+}
+
 /****************************************************************************
  * Name: uart_gdbstub_panic_callback
  *
@@ -64,19 +95,74 @@ static int uart_gdbstub_panic_callback(FAR struct notifier_block *nb,
 {
   FAR struct uart_gdbstub_s *uart_gdbstub =
     container_of(nb, struct uart_gdbstub_s, nb);
+#if CONFIG_SERIAL_GDBSTUB_PANIC_TIMEOUT != 0
+  unsigned int base;
+  unsigned int status;
+  char ch;
+#endif
 
   if (action != PANIC_KERNEL_FINAL)
     {
       return 0;
     }
 
+#if CONFIG_SERIAL_GDBSTUB_PANIC_TIMEOUT == 0
+  gdb_console_message(uart_gdbstub->state,
+                      "Enter panic gdbstub mode!\n");
+#else
+  _alert("Press Y/y key in %d seconds to enter gdb debug mode\n",
+         CONFIG_SERIAL_GDBSTUB_PANIC_TIMEOUT);
+  syslog_flush();
+
+  if (uart_gdbstub->console == NULL)
+    {
+#ifndef CONFIG_SERIAL_GDBSTUB_AUTO_ATTACH
+      uart_gdbstub_attach(uart_gdbstub, false);
+#endif
+      uart_gdbstub->console = uart_gdbstub->dev;
+    }
+
+  base = clock_systime_ticks();
+  while (true)
+    {
+      if (uart_gdbstub->console == uart_gdbstub->dev &&
+          uart_gdbstub->org_ops != NULL)
+        {
+          ch = uart_gdbstub->org_ops->receive(uart_gdbstub->console,
+                                              &status);
+        }
+      else
+        {
+          ch = uart_gdbstub->console->ops->receive(uart_gdbstub->console,
+                                                   &status);
+        }
+
+      if (ch == 'Y' || ch == 'y')
+        {
+          break;
+        }
+
+      if ((clock_systime_ticks()) - base >=
+           SEC2TICK(CONFIG_SERIAL_GDBSTUB_PANIC_TIMEOUT))
+        {
+          _alert("%d seconds passed, exit now\n",
+                 CONFIG_SERIAL_GDBSTUB_PANIC_TIMEOUT);
+          return 0;
+        }
+    }
+#endif
+
+#ifndef CONFIG_SERIAL_GDBSTUB_AUTO_ATTACH
+  uart_gdbstub_attach(uart_gdbstub, true);
+#endif
+
   _alert("Enter panic gdbstub mode, plase use gdb connect to debug\n");
   _alert("Please use gdb of the corresponding architecture to "
          "connect to nuttx");
   _alert("such as: arm-none-eabi-gdb nuttx -ex \"set "
          "target-charset ASCII\" -ex \"target remote /dev/ttyUSB0\"\n");
 
-  gdb_console_message(uart_gdbstub->state, "Enter panic gdbstub mode!\n");
+  syslog_flush();
   gdb_process(uart_gdbstub->state, GDB_STOPREASON_CTRLC, NULL);
   return 0;
 }
@@ -120,7 +206,7 @@ static ssize_t uart_gdbstub_receive(FAR void *priv, FAR void *buf,
     {
       if (uart_gdbstub->org_ops->rxavailable(dev))
         {
-          ptr[i++] = g_uart_gdbstub->org_ops->receive(dev, &state);
+          ptr[i++] = uart_gdbstub->org_ops->receive(dev, &state);
         }
     }
 
@@ -165,14 +251,33 @@ static ssize_t uart_gdbstub_send(FAR void *priv, FAR void *buf, size_t len)
  *
  ****************************************************************************/
 
-int uart_gdbstub_register(FAR uart_dev_t *dev)
+int uart_gdbstub_register(FAR uart_dev_t *dev, FAR const char *path)
 {
   FAR struct uart_gdbstub_s *uart_gdbstub;
 
-  uart_gdbstub = kmm_malloc(sizeof(struct uart_gdbstub_s));
-  if (uart_gdbstub == NULL)
+  if (g_uart_gdbstub == NULL)
     {
-      return -ENOMEM;
+      uart_gdbstub = kmm_zalloc(sizeof(struct uart_gdbstub_s));
+      if (uart_gdbstub == NULL)
+        {
+          return -ENOMEM;
+        }
+
+      g_uart_gdbstub = uart_gdbstub;
+    }
+  else
+    {
+      uart_gdbstub = g_uart_gdbstub;
+    }
+
+  if (dev->isconsole && uart_gdbstub->console == NULL)
+    {
+      uart_gdbstub->console = dev;
+    }
+
+  if (strcmp(path, CONFIG_SERIAL_GDBSTUB_PATH) != 0)
+    {
+      return -EINVAL;
     }
 
   uart_gdbstub->state = gdb_state_init(uart_gdbstub_send,
@@ -184,19 +289,14 @@ int uart_gdbstub_register(FAR uart_dev_t *dev)
       return -ENOMEM;
     }
 
-  g_uart_gdbstub = uart_gdbstub;
-
-  memcpy(&uart_gdbstub->ops, dev->ops, sizeof(struct uart_ops_s));
   uart_gdbstub->dev = dev;
-  uart_gdbstub->org_ops = dev->ops;
-  uart_gdbstub->ops.receive = uart_gdbstub_ctrlc;
-  dev->ops = &uart_gdbstub->ops;
-  uart_setup(dev);
-  uart_attach(dev);
-  uart_enablerxint(dev);
-
   uart_gdbstub->nb.notifier_call = uart_gdbstub_panic_callback;
   panic_notifier_chain_register(&uart_gdbstub->nb);
 
+#ifdef CONFIG_SERIAL_GDBSTUB_AUTO_ATTACH
+  uart_gdbstub_attach(uart_gdbstub, true);
   return 0;
+#else
+  return 1;
+#endif
 }

include/nuttx/serial/serial.h

@@ -561,7 +561,7 @@ int uart_check_special(FAR uart_dev_t *dev, FAR const char *buf,
  ****************************************************************************/
 
 #ifdef CONFIG_SERIAL_GDBSTUB
-int uart_gdbstub_register(FAR uart_dev_t *dev);
+int uart_gdbstub_register(FAR uart_dev_t *dev, FAR const char *path);
 #endif
 
 #undef EXTERN