libvassert: vmware VAssert support.

- BSD-licensed Code gratefully taken from the project at
	  http://en.sourceforge.jp/projects/sfnet_vassertlinuxsdk/

	- For more information on vmware VAssert, a powerful debugging
	  facility usable under vmware, see:
	  www.vmware.com/pdf/ws65_vassert_programming.pdf

lib/libvassert/vassert.h

@@ -0,0 +1,138 @@
+#ifndef _VASSERT_H_
+#define _VASSERT_H_
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif /*__cplusplus*/
+
+#define ALIGNED(n) __attribute__((__aligned__(n)))
+#define VASSERT_TRIGGER_OFFSET 1221
+#define VASSERT_PAGE_SIZE      4096
+
+/* Need to align at 4K. */
+/* Ensure the inReplay flag is on its own page. */
+#pragma pack(1)
+typedef struct VAssert_StateWrapper {
+   char space1[VASSERT_TRIGGER_OFFSET];
+   volatile char inReplay;
+   char space[VASSERT_PAGE_SIZE - VASSERT_TRIGGER_OFFSET - sizeof(char)];
+} VAssert_StateWrapper;
+#pragma pack()
+
+extern VAssert_StateWrapper vassert_state;
+
+/*
+ * User-selectable standard functions.
+ * XXX: Document these, in coordination with the SDK docs.
+ */
+
+#if defined(__KERNEL__)
+#  define KERNEL_VASSERT
+#endif
+
+#ifdef KERNEL_VASSERT
+
+#  ifndef VASSERT_CUSTOM_ASSERT
+#     define VASSERT_CUSTOM_ASSERT(expr)
+#  endif
+
+#  ifndef VASSERT_CUSTOM_ABORT
+#     include <linux/kernel.h>
+#     define VASSERT_CUSTOM_ABORT() ((void)0) // printk(KERN_ALERT"VAssert abort at %s: %d", __FILE__, __LINE__)
+#  endif
+
+#  ifndef VASSERT_CUSTOM_LOG
+#     include <linux/kernel.h>
+#     define VASSERT_CUSTOM_LOG printk
+#  endif
+
+#else
+#  ifndef VASSERT_CUSTOM_ASSERT
+#     include <assert.h>
+#     define VASSERT_CUSTOM_ASSERT assert
+#  endif
+
+#  ifndef VASSERT_CUSTOM_ABORT
+#     include <stdlib.h>
+#     define VASSERT_CUSTOM_ABORT abort
+#  endif
+
+#  ifndef VASSERT_CUSTOM_LOG
+#     include <stdio.h>
+#     define VASSERT_CUSTOM_LOG printf
+#  endif
+#endif
+
+/* Results: 0 if successful, -1 if not. */
+// XXX need to automatic de-register trigger page when the program quits
+extern char VAssert_Init(void);
+extern char VAssert_Uninit(void);
+
+/*
+ * These functions should not be called directly; they need to be wrapped.
+ */
+extern void VAssert_LogMain(const char *format, ...);
+extern void VAssert_GoLiveMain(void);
+extern void VAssert_ReturnToReplayMain(void);
+extern char VAssert_Trace(size_t max_size);
+
+#ifdef VASSERT_ALWAYS_EXECUTE
+
+#define VAssert_Assert(expr)              \
+do {                                      \
+   VASSERT_CUSTOM_ASSERT(expr);           \
+} while (0)
+
+#define VAssert_Log(args)                 \
+do {                                      \
+   VASSERT_CUSTOM_LOG args;               \
+} while (0)
+
+#define VAssert_BeginBlock
+#define VAssert_EndBlock
+
+#else /* VASSERT_ALWAYS_EXECUTE */
+
+#define VAssert_Assert(expr)              \
+do {                                      \
+   if (vassert_state.inReplay) {          \
+      if (!(expr)) {                      \
+         VAssert_GoLiveMain();            \
+         VASSERT_CUSTOM_ABORT();          \
+      } else {                            \
+         VAssert_ReturnToReplayMain();    \
+      }                                   \
+   }                                      \
+} while (0)
+
+#define VAssert_Log(args)                 \
+do {                                      \
+   if (vassert_state.inReplay) {          \
+      VAssert_LogMain args;               \
+      VAssert_ReturnToReplayMain();       \
+   }                                      \
+} while (0)
+
+#define VAssert_BeginBlock if (vassert_state.inReplay)
+#define VAssert_EndBlock VAssert_ReturnToReplayMain()
+
+#endif /* VASSERT_ALWAYS_EXECUTE */
+
+/* 
+ * Record/Replay functionality
+ */
+/*
+ * Results: True if successful, false if not.
+ * Input: True to start recording, false to stop.
+ */
+extern char VAssert_SetRecordingMain(char start);
+
+#define VAssert_StartRecording() VAssert_SetRecordingMain(1)
+#define VAssert_StopRecording() VAssert_SetRecordingMain(0)
+
+#ifdef __cplusplus
+}
+#endif /*__cplusplus*/
+
+#endif /*_VASSERT_H_*/