More 286 fixes.

front/sdl/main.c

@@ -699,8 +699,8 @@ static bool write_default_config(const char *path, bool clean) {
 		"bios=0xFE000,GLABIOS.ROM\n"
 		"uart=0x3F8,4 \t;COM1\n"
 		"uart=0x2F8,3 \t;COM2\n"
-		"cga=\n"
-		";vga=vgabios.bin\n"
+		";cga=\n"
+		"vga=vgabios.bin\n"
 		"disk=\n"
 		"bios=0xE0000,vxtx.bin \t;DISK\n"
 		"rtc=0x240\n"

lib/vxt/cpu.c

@@ -23,7 +23,6 @@
 
 #include "common.h"
 #include "cpu.h"
-#include "include/vxt/vxt.h"
 #include "testing.h"
 
 #include "exec.inl"
@@ -112,43 +111,54 @@ static void prep_exec(CONSTSP(cpu) p) {
 }
 
 static void do_exec(CONSTSP(cpu) p) {
-   const CONSTSP(instruction) inst = &opcode_table[p->opcode];
-   ENSURE(inst->opcode == p->opcode);
-
-   p->ea_cycles = 0;
-   if (inst->modregrm)
-      read_modregrm(p);
-   inst->func(p, inst);
-
-   p->cycles += inst->cycles;
-   p->cycles += p->ea_cycles;
-
-   if (UNLIKELY(p->inst_queue_dirty)) {
-      p->inst_queue_count = 0;
-   } else {
-      #ifndef VXT_NO_PREFETCH
-         prefetch(p, (p->cycles / 2) - p->bus_transfers); // TODO: Round up or down?
-      #endif
-   }
+    const CONSTSP(instruction) inst = &opcode_table[p->opcode];
+    ENSURE(inst->opcode == p->opcode);
+
+    switch (inst->arch) {
+        case ARCH_8086:
+        case ARCH_80186:
+        case ARCH_80286:
+        case ARCH_FPU:
+            p->invalid = false;
+            break;
+        default:
+            p->invalid = true;
+    }
+
+    if (inst->modregrm)
+        read_modregrm(p);
+    inst->func(p, inst);
+
+    if (p->invalid)
+        call_int(p, 6);
+
+    p->cycles += inst->cycles;
+
+    if (UNLIKELY(p->inst_queue_dirty)) {
+        p->inst_queue_count = 0;
+    } else {
+        #ifndef VXT_NO_PREFETCH
+            prefetch(p, (p->cycles / 2) - p->bus_transfers); // TODO: Round up or down?
+        #endif
+    }
 }
 
 int cpu_step(CONSTSP(cpu) p) {
-   VALIDATOR_BEGIN(p, &p->regs);
-
-   prep_exec(p);
-   if (LIKELY(!p->halt)) {
-      read_opcode(p);
-      do_exec(p);
-   } else {
-      p->cycles++;
-   }
+    VALIDATOR_BEGIN(p, &p->regs);
+
+    prep_exec(p);
+    if (LIKELY(!p->halt)) {
+        read_opcode(p);
+        do_exec(p);
+    } else {
+        p->cycles++;
+    }
 
-   const CONSTSP(instruction) inst = &opcode_table[p->opcode];
-   VALIDATOR_END(p, inst->name, p->opcode, inst->modregrm, p->cycles, &p->regs);
-   p->invalid = inst->arch != ARCH_8086;
+    const CONSTSP(instruction) inst = &opcode_table[p->opcode];
+    VALIDATOR_END(p, inst->name, p->opcode, inst->modregrm, p->cycles, &p->regs);
 
-   ENSURE(p->cycles > 0);
-   return p->cycles;
+    ENSURE(p->cycles > 0);
+    return p->cycles;
 }
 
 void cpu_reset_cycle_count(CONSTSP(cpu) p) {
@@ -161,7 +171,8 @@ void cpu_reset(CONSTSP(cpu) p) {
 	p->trap = false;
 	vxt_memclear(&p->regs, sizeof(p->regs));
 
-	p->regs.flags = 0xF002;
+	//p->regs.flags = 0xF002;
+	p->regs.flags = 2; // 286 flag setup
 	p->regs.cs = 0xFFFF;
 	p->regs.debug = false;
 

lib/vxt/cpu.h

@@ -49,7 +49,7 @@ struct address_mode {
 struct cpu {
    struct vxt_registers regs;
    bool trap, halt, int28, invalid;
-   int cycles, ea_cycles;
+   int cycles;
    vxt_word inst_start;
 
    vxt_byte opcode, repeat;

lib/vxt/exec.h

@@ -33,7 +33,6 @@
 #define IRQ(p, n) { VALIDATOR_DISCARD((p)); ENSURE((p)->pic); (p)->pic->pic.irq(VXT_GET_DEVICE_PTR((p)->pic), (n)); }
 #define INST(n) const struct instruction * const n
 #define MOD_TARGET_MEM(mode) ((mode).mod < 3)
-#define ADD_CYCLE_MOD_MEM(p, n) { if (MOD_TARGET_MEM((p->mode))) (p)->cycles += (n); }
 
 enum architecture {
 	ARCH_INVALID,
@@ -96,42 +95,33 @@ static vxt_word get_ea_offset(CONSTSP(cpu) p) {
    CONSTSP(vxt_registers) r = &p->regs;
    CONSTSP(address_mode) m = &p->mode;
    vxt_word ea = 0;
-   int cycles = 0;
 
 	switch (m->mod) {
       case 0:
          switch (m->rm) {
             case 0:
                ea = r->bx + r->si;
-               cycles = 7;
                break;
             case 1:
                ea = r->bx + r->di;
-               cycles = 8;
                break;
             case 2:
                ea = r->bp + r->si;
-               cycles = 8;
                break;
             case 3:
                ea = r->bp + r->di;
-               cycles = 7;
                break;
             case 4:
                ea = r->si;
-               cycles = 5;
                break;
             case 5:
                ea = r->di;
-               cycles = 5;
                break;
             case 6:
                ea = m->disp;
-               cycles = 6;
                break;
             case 7:
                ea = r->bx;
-               cycles = 5;
                break;
          }
          break;
@@ -140,40 +130,31 @@ static vxt_word get_ea_offset(CONSTSP(cpu) p) {
          switch (m->rm) {
             case 0:
                ea = r->bx + r->si + m->disp;
-               cycles = 11;
                break;
             case 1:
                ea = r->bx + r->di + m->disp;
-               cycles = 12;
                break;
             case 2:
                ea = r->bp + r->si + m->disp;
-               cycles = 12;
                break;
             case 3:
                ea = r->bp + r->di + m->disp;
-               cycles = 11;
                break;
             case 4:
                ea = r->si + m->disp;
-               cycles = 9;
                break;
             case 5:
                ea = r->di + m->disp;
-               cycles = 9;
                break;
             case 6:
                ea = r->bp + m->disp;
-               cycles = 9;
                break;
             case 7:
                ea = r->bx + m->disp;
-               cycles = 9;
                break;
          }
          break;
 	}
-   p->ea_cycles = cycles;
 	return ea;
 }