1 files changed, 98 insertions, 0 deletions
diff --git a/Marlin/src/HAL/shared/backtrace/backtrace.cpp b/Marlin/src/HAL/shared/backtrace/backtrace.cpp
new file mode 100644
index 0000000..6cf5e05
--- /dev/null
+++ b/Marlin/src/HAL/shared/backtrace/backtrace.cpp
@@ -0,0 +1,98 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#if defined(__arm__) || defined(__thumb__)
+
+#include "backtrace.h"
+#include "unwinder.h"
+#include "unwmemaccess.h"
+
+#include "../../../core/serial.h"
+#include <stdarg.h>
+
+// Dump a backtrace entry
+static bool UnwReportOut(void* ctx, const UnwReport* bte) {
+  int *p = (int*)ctx;
+
+  (*p)++;
+
+  SERIAL_CHAR('#'); SERIAL_PRINT(*p, DEC); SERIAL_ECHOPGM(" : ");
+  SERIAL_ECHOPGM(bte->name ? bte->name : "unknown"); SERIAL_ECHOPGM("@0x"); SERIAL_PRINT(bte->function, HEX);
+  SERIAL_CHAR('+'); SERIAL_PRINT(bte->address - bte->function,DEC);
+  SERIAL_ECHOPGM(" PC:"); SERIAL_PRINT(bte->address,HEX); SERIAL_CHAR('\n');
+  return true;
+}
+
+#ifdef UNW_DEBUG
+  void UnwPrintf(const char* format, ...) {
+    char dest[256];
+    va_list argptr;
+    va_start(argptr, format);
+    vsprintf(dest, format, argptr);
+    va_end(argptr);
+    TX(&dest[0]);
+  }
+#endif
+
+/* Table of function pointers for passing to the unwinder */
+static const UnwindCallbacks UnwCallbacks = {
+  UnwReportOut,
+  UnwReadW,
+  UnwReadH,
+  UnwReadB
+  #ifdef UNW_DEBUG
+   , UnwPrintf
+  #endif
+};
+
+void backtrace() {
+
+  UnwindFrame btf;
+  uint32_t sp = 0, lr = 0, pc = 0;
+
+  // Capture the values of the registers to perform the traceback
+  __asm__ __volatile__ (
+    " mov %[lrv],lr\n"
+    " mov %[spv],sp\n"
+    " mov %[pcv],pc\n"
+    : [spv]"+r"( sp ),
+      [lrv]"+r"( lr ),
+      [pcv]"+r"( pc )
+    ::
+  );
+
+  // Fill the traceback structure
+  btf.sp = sp;
+  btf.fp = btf.sp;
+  btf.lr = lr;
+  btf.pc = pc | 1; // Force Thumb, as CORTEX only support it
+
+  // Perform a backtrace
+  SERIAL_ERROR_MSG("Backtrace:");
+  int ctr = 0;
+  UnwindStart(&btf, &UnwCallbacks, &ctr);
+}
+
+#else // !__arm__ && !__thumb__
+
+void backtrace() {}
+
+#endif