Arm stack unwinder

Simplified stack unwinder for ARM. This is port of
http://www.mcternan.me.uk/ArmStackUnwinding/
backtrace() is called from UIE() on native targets
and from panicf() on both native and ARM RaaA.

Change-Id: I8e4b3c02490dd60b30aa372fe842d193b8929ce0

1 files changed, 160 insertions, 0 deletions

diff --git a/lib/unwarminder/unwarminder.h b/lib/unwarminder/unwarminder.h
new file mode 100644
index 0000000..1c5adbf
--- /dev/null
+++ b/lib/unwarminder/unwarminder.h
@@ -0,0 +1,160 @@
+/***************************************************************************
+ * ARM Stack Unwinder, Michael.McTernan.2001@cs.bris.ac.uk
+ *
+ * This program is PUBLIC DOMAIN.
+ * This means that there is no copyright and anyone is able to take a copy
+ * for free and use it as they wish, with or without modifications, and in
+ * any context, commerically or otherwise. The only limitation is that I
+ * don't guarantee that the software is fit for any purpose or accept any
+ * liablity for it's use or misuse - this software is without warranty.
+ **************************************************************************/
+/** \file
+ * Interface to the ARM stack unwinding module.
+ **************************************************************************/
+
+#ifndef UNWARMINDER_H
+#define UNWARMINDER_H
+
+/***************************************************************************
+ * Nested Include Files
+ **************************************************************************/
+
+#include "types.h"
+
+/***************************************************************************
+ * Manifest Constants
+ **************************************************************************/
+
+/** \def UNW_DEBUG
+ * If this define is set, additional information will be produced while
+ * unwinding the stack to allow debug of the unwind module itself.
+ */
+/* #define UNW_DEBUG 1 */
+
+/***************************************************************************
+ * Type Definitions
+ **************************************************************************/
+
+/** Possible results for UnwindStart to return.
+ */
+typedef enum UnwResultTag
+{
+    /** Unwinding was successful and complete. */
+    UNWIND_SUCCESS = 0,
+
+    /** More than UNW_MAX_INSTR_COUNT instructions were interpreted. */
+    UNWIND_EXHAUSTED,
+
+    /** Unwinding stopped because the reporting func returned FALSE. */
+    UNWIND_TRUNCATED,
+
+    /** Read data was found to be inconsistent. */
+    UNWIND_INCONSISTENT,
+
+    /** Unsupported instruction or data found. */
+    UNWIND_UNSUPPORTED,
+
+    /** General failure. */
+    UNWIND_FAILURE,
+
+    /** Illegal instruction. */
+    UNWIND_ILLEGAL_INSTR,
+
+    /** Unwinding hit the reset vector. */
+    UNWIND_RESET,
+
+    /** Failed read for an instruction word. */
+    UNWIND_IREAD_W_FAIL,
+
+    /** Failed read for an instruction half-word. */
+    UNWIND_IREAD_H_FAIL,
+
+    /** Failed read for an instruction byte. */
+    UNWIND_IREAD_B_FAIL,
+
+    /** Failed read for a data word. */
+    UNWIND_DREAD_W_FAIL,
+
+    /** Failed read for a data half-word. */
+    UNWIND_DREAD_H_FAIL,
+
+    /** Failed read for a data byte. */
+    UNWIND_DREAD_B_FAIL,
+
+    /** Failed write for a data word. */
+    UNWIND_DWRITE_W_FAIL
+}
+UnwResult;
+
+/** Type for function pointer for result callback.
+ * The function is passed two parameters, the first is a void * pointer,
+ * and the second is the return address of the function.  The bottom bit
+ * of the passed address indicates the execution mode; if it is set,
+ * the execution mode at the return address is Thumb, otherwise it is
+ * ARM.
+ *
+ * The return value of this function determines whether unwinding should
+ * continue or not.  If TRUE is returned, unwinding will continue and the
+ * report function maybe called again in future.  If FALSE is returned,
+ * unwinding will stop with UnwindStart() returning UNWIND_TRUNCATED.
+ */
+typedef Boolean (*UnwindReportFunc)(void   *data,
+                                    Int32   address);
+
+/** Structure that holds memory callback function pointers.
+ */
+typedef struct UnwindCallbacksTag
+{
+    /** Report an unwind result. */
+    UnwindReportFunc report;
+
+    /** Read a 32 bit word from memory.
+     * The memory address to be read is passed as \a address, and
+     * \a *val is expected to be populated with the read value.
+     * If the address cannot or should not be read, FALSE can be
+     * returned to indicate that unwinding should stop.  If TRUE
+     * is returned, \a *val is assumed to be valid and unwinding
+     * will continue.
+     */
+    Boolean (*readW)(const Int32 address, Int32 *val);
+
+    /** Read a 16 bit half-word from memory.
+     * This function has the same usage as for readW, but is expected
+     * to read only a 16 bit value.
+     */
+    Boolean (*readH)(const Int32 address, Int16 *val);
+
+    /** Read a byte from memory.
+     * This function has the same usage as for readW, but is expected
+     * to read only an 8 bit value.
+     */
+    Boolean (*readB)(const Int32 address, Int8  *val);
+
+#if defined(UNW_DEBUG)
+    /** Print a formatted line for debug. */
+    int (*printf)(const char *format, ...);
+#endif
+
+}
+UnwindCallbacks;
+
+/***************************************************************************
+ *  Macros
+ **************************************************************************/
+
+/***************************************************************************
+ *  Function Prototypes
+ **************************************************************************/
+
+/** Start unwinding the current stack.
+ * This will unwind the stack starting at the PC value supplied and 
+ * the stack pointer value supplied.
+ */
+UnwResult UnwindStart(Int32                  pcValue,
+                      Int32                  spValue,
+                      const UnwindCallbacks *cb,
+                      void                  *data);
+
+#endif /* UNWARMINDER_H */
+
+/* END OF FILE */