tests: add custom offset-wrap tests

tests/compare_test.go

@@ -5,10 +5,15 @@ Tests for the 6502 CPU emulator, comparing it with the transistor-level simulati
 package tests
 
 import (
+	"fmt"
 	"io/ioutil"
 	"testing"
 
+	"github.com/zellyn/go6502/asm"
+	"github.com/zellyn/go6502/asm/flavors/scma"
+	"github.com/zellyn/go6502/asm/lines"
 	"github.com/zellyn/go6502/cpu"
+	"github.com/zellyn/go6502/opcodes"
 	"github.com/zellyn/go6502/visual"
 )
 
@@ -84,3 +89,101 @@ func TestFunctionalTestCompare(t *testing.T) {
 		}
 	}
 }
+
+func getTestProgram() ([]byte, error) {
+	o := lines.NewTestOpener()
+	a := asm.NewAssembler(scma.New(opcodes.SetSweet16), o)
+	o["FILE"] = `
+    cld
+    ldx #$ff
+    txs
+    lda #$ff
+    sta $70
+    lda #$0e
+    sta $71
+    ldy #0
+    adc ($70),Y
+    ldy #1
+    clc
+    adc ($70),Y
+    sec
+    adc ($70),Y
+    ldx #0
+    inc $3412,X
+    ldx $ff
+    clc
+    inc $3412,X
+    sec
+    inc $3412,X
+    jmp 0
+`
+	if err := a.Load("FILE", 0); err != nil {
+		return nil, err
+	}
+	if err := a.Pass2(); err != nil {
+		return nil, err
+	}
+	bb, err := a.RawBytes()
+	if err != nil {
+		return nil, fmt.Errorf("a.RawBytes() failed: %v", err)
+	}
+	return bb, nil
+}
+
+// Test a custom test program against the instruction- and gate-level
+// CPU emulations, making sure they have the same memory access
+// patterns.
+func TestCustomTestCompare(t *testing.T) {
+	bytes, err := getTestProgram()
+	if err != nil {
+		t.Fatalf("Failed to assemble test program: %v", err)
+	}
+	var m Memorizer
+	START := 0x6000
+	copy(m.mem1[START:], bytes)
+	copy(m.mem2[START:], bytes)
+	// Set the RESET vector to jump to the tests
+	m.mem1[0xFFFC] = byte(START % 256)
+	m.mem1[0xFFFD] = byte(START / 256)
+	m.mem2[0xFFFC] = byte(START % 256)
+	m.mem2[0xFFFD] = byte(START / 256)
+
+	v := visual.NewCPU(&m)
+	v.Reset()
+	for i := 0; i < 8; i++ {
+		v.Step()
+	}
+
+	var cc CycleCount
+	c := cpu.NewCPU(&m, cc.Tick, cpu.VERSION_6502)
+	c.Reset()
+
+	m.Reset(MODE_RECORD)
+	v.Step()
+	v.Step()
+	m.Verify()
+	c.Step()
+	if len(m.errors) > 0 {
+		t.Fatal("Errors on reset", m.errors)
+	}
+
+	for {
+		m.Record()
+		for i := 0; i < 1000; i++ {
+			v.Step()
+		}
+		m.Verify()
+		for len(m.ops) > 7 {
+			s := status(c, &m.mem2, uint64(cc))
+			c.Step()
+			if len(m.errors) > 0 {
+				t.Fatalf("Error at %v: %v", s, m.errors)
+			}
+			pc := c.PC()
+			fmt.Printf("%04X\n", pc)
+			if pc == 0x00 {
+				t.Fatalf("bang")
+			}
+		}
+	}
+}