Initial check-in of the MIPS simulator. Work still needs to be done on

the run-time support code (interp.c) to provide better tracing, and
also to add profiling and architecture specific support. At the moment
the simulator has a fixed size, fixed address memory area, and
simulates a subset of the IDT monitor calls (enough to execute test
programs).

The other major feature (could even be a bug) is that the simulator
makes use of the GCC "long long" extension. Work has been started to
make this a build configuration option... but there is still a lot of
this to be done.

1 files changed, 73 insertions, 0 deletions

diff --git a/sim/mips/support.h b/sim/mips/support.h
new file mode 100644
index 0000000..e1f0176
--- /dev/null
+++ b/sim/mips/support.h
@@ -0,0 +1,73 @@
+/*> support.h <*/
+
+#ifndef __support_h
+#define __support_h
+
+/* For 64bit values either use the GCC "long long" feature, or have a
+   structure made from two 32bit values. We can then have macros for
+   accessing the LO and HI parts of the value. Also we can provide
+   macros for the basic operations we want to perform on 64bit values
+   (i.e. ADD64,SUB64,SHIFTLEFT64, etc.). This means we should be able
+   to host the simulator on non-GCC compilers, and 32bit only
+   architectures if desired. */
+
+/* Control via a build boolean for the moment */
+#if 1 && defined(__GNUC__)
+
+typedef long long word64;
+typedef unsigned long long uword64;
+
+#define WORD64LO(t)     (unsigned int)((t)&0xFFFFFFFF)
+#define WORD64HI(t)     (unsigned int)((t)>>32)
+
+/* Sign-extend the given value (e) as a value (b) bits long. We cannot
+   assume the HI32bits of the operand are zero, so we must perform a
+   mask to ensure we can use the simple subtraction to sign-extend. */
+#define SIGNEXTEND(e,b) (((e) & ((unsigned long long)1 << ((b) - 1))) ? (((e) & (((unsigned long long)1 << (b)) - 1)) - ((unsigned long long)1 << (b))) : (e))
+
+/* Check if a value will fit within a word (unsigned int): */
+#define NOTWORDVALUE(v) ((((((unsigned long long)(v)>>32) == 0) && !((v) & ((unsigned)1 << 31))) || ((((unsigned long long)(v)>>32) == 0xFFFFFFFF) && ((v) & ((unsigned)1 << 31)))) ? (1 == 0) : (1 == 1))
+
+/* Check if a value will fit within a halfword: */
+#define NOTHALFWORDVALUE(v) ((((((unsigned long long)(v)>>16) == 0) && !((v) & ((unsigned)1 << 15))) || (((((unsigned long long)(v)>>32) == 0xFFFFFFFF) && ((((unsigned long long)(v)>>16) & 0xFFFF) == 0xFFFF)) && ((v) & ((unsigned)1 << 15)))) ? (1 == 0) : (1 == 1))
+
+/* The following should be executed once at the start of day in the
+   main emulator control function. The simulator assumes char is
+   8bits, and from this: */
+#define CHECKSIM() {\
+                     if (sizeof(int) != (4 * sizeof(char)))\
+                      SignalException(SimulatorFault,"sizeof(int) != 4");\
+                     if (sizeof(long long) != (8 * sizeof(char)))\
+                      SignalException(SimulatorFault,"sizeof(long long) != 8");\
+                   }
+
+#else /* non-GCC build */
+
+#error "non-GCC build to be completed" /* avoid using long long */
+
+typedef struct word64 {
+ unsigned int lo;
+ unsigned int hi;
+} word64;
+
+#define WORD64LO(t)     (unsigned int)(t.lo)
+#define WORD64HI(t)     (unsigned int)(t.hi)
+
+/* TODO: Update these to manipulate the split structure values */
+#define SIGNEXTEND(e,b)         /* TODO */
+#define NOTWORDVALUE(v)         /* TODO */
+#define NOTHALFWORDVALUE(v)     /* TODO */
+
+/* The following should be executed once at the start of day in the
+   main emulator control function. The simulator assumes char is
+   8bits, and from this: */
+#define CHECKSIM() {\
+                     if (sizeof(int) != (4 * sizeof(char)))\
+                      SignalException(SimulatorFault,"sizeof(int) != 4");\a
+                   }
+
+#endif /* non-GCC build */
+
+#endif /* __support_h */
+
+/*> EOF support.h <*/