Reorganize instruction table handling, use return value for exceptions

1 files changed, 14 insertions, 1 deletions

diff --git a/instruction.h b/instruction.h
index 1053936..5a268d3 100644
--- a/instruction.h
+++ b/instruction.h
@@ -202,13 +202,26 @@ enum {
 #define INSTR_ERR		-1	/* Error in instruction */
 #define PC_INC_NORMAL		0	/* Normal PC increment after instruction */
 #define PC_INC_BY_INSTR		1	/* PC got incremented by instruction */
-#define INSTR_EXECPTION		2	/* Instruction generated an exception */
+#define INSTR_EXCEPTION_BASE	255	/* Instruction generated an exception */
+
+#define EXCEPTION(cause)	(INSTR_EXCEPTION_BASE + (cause))
+#define IS_EXCEPTION(ret)	((ret) >= INSTR_EXCEPTION_BASE)
+#define EXCEPTION_CAUSE(ret)	((uint8_t)((ret) - INSTR_EXCEPTION_BASE))
 
 /* Forward declaration */
 struct nios2;
 
 typedef int (*instruction_handler)(struct nios2 *cpu, uint32_t opcode);
 
+struct instruction {
+	const char *name;
+	instruction_handler handler;
+};
+
+#define INSTRUCTION(name)		{ __stringify(name), name }
+#define INSTRUCTION_NOP(name)		{ __stringify(name), nop }
+#define INSTRUCTION_UNIMPLEMENTED(name)	{ __stringify(name), unimplemented }
+
 extern instruction_handler instruction_get_handler(uint32_t code);
 extern const char *instruction_get_string(uint32_t code);