pa2.2: add ftrace

nemu/Kconfig

@@ -143,8 +143,11 @@ config TRACE_END
 
 config ITRACE
   depends on TRACE && TARGET_NATIVE_ELF && ENGINE_INTERPRETER
-  bool "Enable instruction tracer"
+  bool "Enable instruction tracing"
   default y
+  help
+    Instraction tracing will log past instructions into a ring buffer
+    and print them when NEMU exit unexpectedly.
 
 config ITRACE_COND
   depends on ITRACE
@@ -158,8 +161,8 @@ config ITRACE_BUFFER
 
 config MTRACE
   depends on TRACE && TARGET_NATIVE_ELF && ENGINE_INTERPRETER
-  bool "Enable memory tracer"
-
+  bool "Enable memory tracing"
+  default n
 
 config MTRACE_RANGE
   depends on MTRACE
@@ -174,6 +177,21 @@ config MTRACE_RANGE_MAX
   int "Max range count in MTRACE_RANGE"
   default 10
 
+config FTRACE
+  depends on TRACE && TARGET_NATIVE_ELF && ENGINE_INTERPRETER
+  bool "Enable function tracing"
+  default y
+
+config FTRACE_STACK_SIZE
+  depends on FTRACE
+  int "Max function track stack size"
+  default 100
+
+config FTRACE_LOG
+  depends on FTRACE
+  bool "Print log when entering a funciton"
+  default n
+
 config DIFFTEST
   depends on TARGET_NATIVE_ELF
   bool "Enable differential testing"