samples: gdbstub: doc: Remove redundant sample

Remove gdbstub sample (samples/subsys/debug/gdbstub) as duplicated
by a test (tests/subsys/debug/gdbstub).

Update the GDB stub documentation.

Signed-off-by: Dmitrii Golovanov <dmitrii.golovanov@intel.com>

doc/services/debugging/gdbstub.rst

@@ -87,8 +87,9 @@ Using Serial Backend
 Example
 *******
 
-This is an example using ``samples/subsys/debug/gdbstub`` to demonstrate
+This is an example to demonstrate how GDB stub works.
-how GDB stub works.
+You can also refer to ``tests/subsys/debug/gdbstub``
+for its implementation as a Twister test.
 
 #. Open two terminal windows.
 

samples/subsys/debug/gdbstub/CMakeLists.txt

@@ -1,12 +0,0 @@
-# SPDX-License-Identifier: Apache-2.0
-
-cmake_minimum_required(VERSION 3.20.0)
-
-if(BOARD MATCHES "qemu_x86")
-  list(APPEND QEMU_EXTRA_FLAGS -serial tcp:127.0.0.1:5678,server)
-endif()
-
-find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
-project(debug)
-
-target_sources(app PRIVATE src/main.c)

samples/subsys/debug/gdbstub/README.rst

@@ -1,31 +0,0 @@
-.. zephyr:code-sample:: gdb-debug
-   :name: GDB debug
-
-   Use GDB Remote Serial Protocol to debug a Zephyr application running on QEMU.
-
-Overview
-********
-
-A simple sample that can be used with QEMU to show debug using GDB
-Remote Serial Protocol (RSP) capabilities.
-
-Building and Running
-********************
-
-This application can be built and executed on QEMU as follows:
-
-.. zephyr-app-commands::
-   :zephyr-app: samples/subsys/debug/gdbstub
-   :host-os: unix
-   :board: qemu_x86
-   :goals: run
-   :compact:
-
-Open a new terminal and use gdb to connect to the running qemu as follows:
-
-.. code-block:: bash
-
-    gdb build/zephyr/zephyr.elf
-    (gdb) target remote :5678
-
-Exit QEMU by pressing :kbd:`CTRL+A` :kbd:`x`.

samples/subsys/debug/gdbstub/boards/qemu_x86.overlay

@@ -1,7 +0,0 @@
-/* SPDX-License-Identifier: Apache-2.0 */
-
-/ {
-	chosen {
-		zephyr,gdbstub-uart = &uart1;
-	};
-};

samples/subsys/debug/gdbstub/boards/qemu_x86_64.overlay

@@ -1,7 +0,0 @@
-/* SPDX-License-Identifier: Apache-2.0 */
-
-/ {
-	chosen {
-		zephyr,gdbstub-uart = &uart1;
-	};
-};

samples/subsys/debug/gdbstub/prj.conf

@@ -1,4 +0,0 @@
-CONFIG_GDBSTUB=y
-CONFIG_NO_OPTIMIZATIONS=y
-CONFIG_USERSPACE=y
-CONFIG_KOBJECT_TEXT_AREA=4096

samples/subsys/debug/gdbstub/run.gdbinit

@@ -1,17 +0,0 @@
-set pagination off
-#symbol-file build/zephyr/zephyr.elf
-target remote :5678
-b test
-b main.c:33
-c
-
-s
-set var a = 2
-c
-if ret == 6
-	printf "PASSED\n"
-	quit 0
-else
-	printf "FAILED\n"
-	quit 1
-end

samples/subsys/debug/gdbstub/sample.yaml

@@ -1,15 +0,0 @@
-#
-# Copyright (c) 2020 intel Corporation.
-#
-# SPDX-License-Identifier: Apache-2.0
-#
-
-sample:
-  name: gdbstub sample
-tests:
-  sample.debug.gdbstub:
-    build_only: true
-    platform_allow: qemu_x86
-    tags:
-      - debug
-      - gdbstub

samples/subsys/debug/gdbstub/src/main.c

@@ -1,38 +0,0 @@
-/*
- * Copyright (c) 2020 Intel Corporation.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-#include <zephyr/kernel.h>
-#include <zephyr/sys/printk.h>
-
-#define STACKSIZE 512
-
-static int test(void)
-{
-	int a;
-	int b;
-
-	a = 10;
-	b = a * 2;
-
-	return a + b;
-}
-
-static void thread_entry(void *p1, void *p2, void *p3)
-{
-	printk("Hello from user thread!\n");
-}
-
-int main(void)
-{
-	int ret;
-
-	ret = test();
-	printk("%d\n", ret);
-	return 0;
-}
-
-K_THREAD_DEFINE(thread, STACKSIZE, thread_entry, NULL, NULL, NULL,
-		7, K_USER, 0);