3 files changed, 145 insertions, 0 deletions
diff --git a/usr.bin/oemu/cpu.c b/usr.bin/oemu/cpu.c
index 61568f2..58dd134 100644
--- a/usr.bin/oemu/cpu.c
+++ b/usr.bin/oemu/cpu.c
@@ -100,6 +100,104 @@ cpu_dec(struct oemu_cpu *cpu, inst_t *inst)
 }
 
 /*
+ * Decode the INST_ADD instruction
+ *
+ * @cpu: CPU that is executing
+ * @inst: Instruction dword
+ */
+static void
+cpu_add(struct oemu_cpu *cpu, inst_t *inst)
+{
+    struct cpu_regs *regs = &cpu->regs;
+    imm_t imm;
+
+    if (inst->rd > NELEM(regs->xreg)) {
+        printf("bad register operand for 'add'\n");
+        return;
+    }
+
+    imm = regs->xreg[inst->rd];
+    regs->xreg[inst->rd] += inst->imm;
+    printf("%d + %d -> X%d, new=%d\n",
+        imm, inst->imm, inst->rd, regs->xreg[inst->rd]);
+}
+
+/*
+ * Decode the INST_SUB instruction
+ *
+ * @cpu: CPU that is executing
+ * @inst: Instruction dword
+ */
+static void
+cpu_sub(struct oemu_cpu *cpu, inst_t *inst)
+{
+    struct cpu_regs *regs = &cpu->regs;
+    imm_t imm;
+
+    if (inst->rd > NELEM(regs->xreg)) {
+        printf("bad register operand for 'sub'\n");
+        return;
+    }
+
+    imm = regs->xreg[inst->rd];
+    regs->xreg[inst->rd] -= inst->imm;
+    printf("%d - %d -> X%d, new=%d\n",
+        imm, inst->imm, inst->rd, regs->xreg[inst->rd]);
+}
+
+/*
+ * Decode the INST_MUL instruction
+ *
+ * @cpu: CPU that is executing
+ * @inst: Instruction dword
+ */
+static void
+cpu_mul(struct oemu_cpu *cpu, inst_t *inst)
+{
+    struct cpu_regs *regs = &cpu->regs;
+    imm_t imm;
+
+    if (inst->rd > NELEM(regs->xreg)) {
+        printf("bad register operand for 'mul'\n");
+        return;
+    }
+
+    imm = regs->xreg[inst->rd];
+    regs->xreg[inst->rd] *= inst->imm;
+    printf("%d * %d -> X%d, new=%d\n",
+        imm, inst->imm, inst->rd, regs->xreg[inst->rd]);
+}
+
+/*
+ * Decode the INST_DIV instruction
+ *
+ * @cpu: CPU that is executing
+ * @inst: Instruction dword
+ */
+static void
+cpu_div(struct oemu_cpu *cpu, inst_t *inst)
+{
+    struct cpu_regs *regs = &cpu->regs;
+    imm_t imm;
+
+    if (inst->rd > NELEM(regs->xreg)) {
+        printf("bad register operand for 'div'\n");
+        return;
+    }
+
+    imm = regs->xreg[inst->rd];
+    if (imm == 0) {
+        /* TODO: Some sort of interrupt */
+        printf("** DIVIDE BY ZERO **\n");
+        return;
+    }
+
+    regs->xreg[inst->rd] /= inst->imm;
+    printf("%d / %d -> X%d, new=%d\n",
+        imm, inst->imm, inst->rd, regs->xreg[inst->rd]);
+}
+
+/*
  * Reset a CPU to a default state
  */
 void
@@ -112,6 +210,31 @@ cpu_reset(struct oemu_cpu *cpu)
     memset(regs->xreg, 0x0, sizeof(regs->xreg));
 }
 
+void
+cpu_regdump(struct oemu_cpu *cpu)
+{
+    struct cpu_regs *regs;
+
+    regs = &cpu->regs;
+    printf(
+        "X0=%p, X1=%p, X2=%p\n"
+        "X3=%p, X4=%p, X5=%p\n"
+        "X6=%p, X7=%p, X8=%p\n"
+        "X9=%p, X10=%p, X11=%p\n"
+        "X12=%p, X13=%p, X14=%p\n"
+        "X15=%p, IP=%p\n",
+        regs->xreg[0], regs->xreg[1],
+        regs->xreg[2], regs->xreg[3],
+        regs->xreg[4], regs->xreg[5],
+        regs->xreg[6], regs->xreg[7],
+        regs->xreg[8], regs->xreg[9],
+        regs->xreg[10], regs->xreg[11],
+        regs->xreg[12], regs->xreg[13],
+        regs->xreg[14], regs->xreg[15],
+        regs->ip
+    );
+}
+
 /*
  * Main instruction execution loop.
  */
@@ -135,6 +258,24 @@ cpu_kick(struct oemu_cpu *cpu, struct sysmem *mem)
         case INST_DEC:
             cpu_dec(cpu, inst);
             break;
+        case INST_ADD:
+            cpu_add(cpu, inst);
+            break;
+        case INST_SUB:
+            cpu_sub(cpu, inst);
+            break;
+        case INST_MUL:
+            cpu_mul(cpu, inst);
+            break;
+        case INST_DIV:
+            cpu_div(cpu, inst);
+            break;
+        }
+
+        /* Is this a halt instruction? */
+        if (inst->opcode == INST_HLT) {
+            printf("HALTED\n");
+            break;
         }
 
         if (regs->ip >= MEMORY_SIZE) {
@@ -143,4 +284,6 @@ cpu_kick(struct oemu_cpu *cpu, struct sysmem *mem)
 
         regs->ip += sizeof(*inst);
     }
+
+    cpu_regdump(cpu);
 }
diff --git a/usr.bin/oemu/include/oemu/cpu.h b/usr.bin/oemu/include/oemu/cpu.h
index df4cc80..78b92da 100644
--- a/usr.bin/oemu/include/oemu/cpu.h
+++ b/usr.bin/oemu/include/oemu/cpu.h
@@ -63,6 +63,7 @@ struct oemu_cpu {
     struct cpu_regs regs;
 };
 
+void cpu_regdump(struct oemu_cpu *cpu);
 void cpu_reset(struct oemu_cpu *cpu);
 void cpu_kick(struct oemu_cpu *cpu, struct sysmem *mem);
 
diff --git a/usr.bin/oemu/include/oemu/osmx64.h b/usr.bin/oemu/include/oemu/osmx64.h
index d7ea8b1..e9baae0 100644
--- a/usr.bin/oemu/include/oemu/osmx64.h
+++ b/usr.bin/oemu/include/oemu/osmx64.h
@@ -47,6 +47,7 @@
 #define INST_SLL      0x11    /* Shift left logical operation */
 #define INST_SRL      0x12    /* Shift right logical operation */
 #define INST_MOV_IMM  0x13    /* Data move operation from IMM */
+#define INST_HLT      0x14    /* Halt */
 
 /* Registers */
 #define REG_X0   0x00