From 0dc36c6bc645635f28c0a4951b804f64609d5d6b Mon Sep 17 00:00:00 2001
From: Forest Belton <65484+forestbelton@users.noreply.github.com>
Date: Wed, 23 Jun 2021 15:21:26 -0400
Subject: [PATCH] Add secondary opcodes and error handling

---
 Makefile       |  3 ++-
 include/insn.h | 31 +++++++++++++++++++++++++++++++
 include/util.h |  6 ++++++
 src/cpu.c      | 17 -----------------
 src/insn.c     | 31 +++++++++++++++++++++++++++++++
 src/util.c     | 15 +++++++++++++++
 6 files changed, 85 insertions(+), 18 deletions(-)
 create mode 100644 include/util.h
 delete mode 100644 src/cpu.c
 create mode 100644 src/insn.c
 create mode 100644 src/util.c

diff --git a/Makefile b/Makefile
index 5078efc..780303a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,6 @@
 CFLAGS ?= -Wall -Wextra -Iinclude
 
+HFILES := $(shell find include -type f -name '*.h')
 CFILES := $(shell find src -type f -name '*.c')
 OFILES := $(CFILES:%.c=%.o)
 
@@ -8,7 +9,7 @@ OFILES := $(CFILES:%.c=%.o)
 psxc: $(OFILES)
 	$(CC) $(OFILES) -o $@
 
-%.o: %.c
+%.o: %.c $(HFILES)
 	$(CC) $(CFLAGS) -c $< -o $@
 
 clean:
diff --git a/include/insn.h b/include/insn.h
index 611c231..a35cbf3 100644
--- a/include/insn.h
+++ b/include/insn.h
@@ -1,6 +1,8 @@
 #ifndef PSXC_INSN_H_
 #define PSXC_INSN_H_
 
+#include "cpu.h"
+
 #include <stdint.h>
 
 typedef enum {
@@ -52,10 +54,39 @@ static inline op_primary_t extract_primary_op(uint32_t insn) {
 
 typedef enum {
   SLL = 0x00,
+  SRL = 0x02,
+  SRA = 0x03,
+  SLLV = 0x04,
+  SRLV = 0x06,
+  SRAV = 0x07,
+  JR = 0x08,
+  JALR = 0x09,
+  SYSCALL = 0x0c,
+  BREAK = 0x0d,
+  MFHI = 0x10,
+  MTHI = 0x11,
+  MFLO = 0x12,
+  MTLO = 0x13,
+  MULT = 0x18,
+  MULTU = 0x19,
+  DIV = 0x1a,
+  DIVU = 0x1b,
+  ADD = 0x20,
+  ADDU = 0x21,
+  SUB = 0x22,
+  SUBU = 0x23,
+  AND = 0x24,
+  OR = 0x25,
+  XOR = 0x26,
+  NOR = 0x27,
+  SLT = 0x2a,
+  SLTU = 0x2b,
 } op_secondary_t;
 
 static inline op_secondary_t extract_secondary_op(uint32_t insn) {
   return (insn >> 0) & 0x3f;
 }
 
+void insn_execute(cpu_t *cpu, uint32_t insn);
+
 #endif
diff --git a/include/util.h b/include/util.h
new file mode 100644
index 0000000..11061bb
--- /dev/null
+++ b/include/util.h
@@ -0,0 +1,6 @@
+#ifndef PSXC_UTIL_H_
+#define PSXC_UTIL_H_
+
+void fatal(const char *fmt, ...);
+
+#endif
diff --git a/src/cpu.c b/src/cpu.c
deleted file mode 100644
index d3fac3e..0000000
--- a/src/cpu.c
+++ /dev/null
@@ -1,17 +0,0 @@
-#include "cpu.h"
-#include "insn.h"
-
-static cpu_insn_handler primary_insn_handler[0x34] = {};
-static cpu_insn_handler secondary_insn_handler[0x34] = {};
-
-void cpu_execute_insn(cpu_t *cpu, uint32_t insn) {
-  const op_primary_t op = extract_primary_op(insn);
-
-  if (op == SPECIAL) {
-    const op_secondary_t op2 = extract_secondary_op(insn);
-    secondary_insn_handler[op2](cpu, insn);
-    return;
-  }
-
-  primary_insn_handler[op](cpu, insn);
-}
diff --git a/src/insn.c b/src/insn.c
new file mode 100644
index 0000000..e3491d4
--- /dev/null
+++ b/src/insn.c
@@ -0,0 +1,31 @@
+#include "insn.h"
+#include "cpu.h"
+#include "util.h"
+
+#include <stddef.h>
+
+#define TABLE_SIZE 0x34
+
+static cpu_insn_handler primary_insn_handler[TABLE_SIZE] = {NULL};
+static cpu_insn_handler secondary_insn_handler[TABLE_SIZE] = {NULL};
+
+void insn_execute(cpu_t *cpu, uint32_t insn) {
+  const op_primary_t op = extract_primary_op(insn);
+
+  if (op == SPECIAL) {
+    const op_secondary_t op2 = extract_secondary_op(insn);
+
+    if (op2 > TABLE_SIZE || secondary_insn_handler[op2] == NULL) {
+      fatal("unsupported instruction: insn=%08x, op=%02x, op2=%02x", insn, op,
+            op2);
+    }
+
+    secondary_insn_handler[op2](cpu, insn);
+  }
+
+  if (op > TABLE_SIZE || primary_insn_handler[op] == NULL) {
+    fatal("unsupported instruction: insn=%08x, op=%02x", insn, op);
+  }
+
+  primary_insn_handler[op](cpu, insn);
+}
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..59c0b3e
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,15 @@
+#include "util.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void fatal(const char *fmt, ...) {
+  va_list args;
+
+  va_start(args, fmt);
+  vfprintf(stderr, fmt, args);
+  va_end(args);
+
+  exit(EXIT_FAILURE);
+}