gdb:add dmesg command show ramlog buffer data as syslog

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

tools/gdb/dmesg.py

@@ -0,0 +1,49 @@
+############################################################################
+# tools/gdb/dmesg.py
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.  The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+import gdb
+import utils
+
+CONFIG_RAMLOG_SYSLOG = utils.get_symbol_value("CONFIG_RAMLOG_SYSLOG")
+
+
+class Dmesg(gdb.Command):
+    def __init__(self):
+        super(Dmesg, self).__init__("dmesg", gdb.COMMAND_USER)
+
+    def invoke(self, args, from_tty):
+        sysdev = utils.gdb_eval_or_none("g_sysdev")
+        if not sysdev:
+            gdb.write("RAM log not available.\n")
+            return
+
+        rl_head = sysdev["rl_header"]
+        rl_bufsize = sysdev["rl_bufsize"]
+        gdb.write("Ramlog have %d bytes to show\n" % rl_bufsize)
+
+        inf = gdb.selected_inferior()
+        buf = inf.read_memory(rl_head["rl_buffer"], rl_bufsize)
+        clean_data = bytes(buf).replace(b"\x00", "␀".encode("utf-8"))
+        gdb.write(clean_data.decode("utf-8"))
+        gdb.write("\n")
+
+
+if CONFIG_RAMLOG_SYSLOG:
+    Dmesg()