mips: add native backtrace implementation

Should make debugging crashes on native MIPS targets far easier.
This is by no means a 100% complete or robust implementation but
it seems to handle the vast majority of functions.

Change-Id: Id5f430270e02b5092b79026b6876675c784aa649

3 files changed, 13 insertions, 3 deletions

diff --git a/firmware/export/backtrace.h b/firmware/export/backtrace.h
index 283e293b2a..fb007ab004 100644
--- a/firmware/export/backtrace.h
+++ b/firmware/export/backtrace.h
@@ -25,6 +25,9 @@
 #ifdef BACKTRACE_UNWARMINDER
 #include "backtrace-unwarminder.h"
 #endif
+#ifdef BACKTRACE_MIPSUNWINDER
+#include "backtrace-mipsunwinder.h"
+#endif
 
 /* Print a backtrace using lcd_* functions, starting at the given line and updating
  * the line number. On targets that support it (typically native targets), the
diff --git a/firmware/export/system.h b/firmware/export/system.h
index 9558be559a..def3122205 100644
--- a/firmware/export/system.h
+++ b/firmware/export/system.h
@@ -258,7 +258,8 @@ static inline void cpu_boost_unlock(void)
 #endif
 
 /* Define this if target has support for generating backtraces */
-#ifdef CPU_ARM
+#if defined(CPU_ARM) || \
+    (defined(CPU_MIPS) && (CONFIG_PLATFORM & PLATFORM_NATIVE))
     #define HAVE_RB_BACKTRACE
 #endif
 
diff --git a/firmware/panic.c b/firmware/panic.c
index fcfa8b2bb8..586ecb6e0a 100644
--- a/firmware/panic.c
+++ b/firmware/panic.c
@@ -32,9 +32,9 @@
 #include "system.h"
 #include "logf.h"
 
-#if defined(CPU_ARM)
+#ifdef HAVE_RB_BACKTRACE
 #include "gcc_extensions.h"
-#include <backtrace.h>
+#include "backtrace.h"
 #endif
 
 static char panic_buf[128];
@@ -65,6 +65,12 @@ void panicf_f( const char *fmt, ...)
                  );
 
     int pc = (int)__builtin_return_address(0);
+#elif defined(BACKTRACE_MIPSUNWINDER)
+void panicf( const char *fmt, ... )
+{
+    /* NOTE: these are obtained by the backtrace lib */
+    const int pc = 0;
+    const int sp = 0;
 #else
 void panicf( const char *fmt, ...)
 {