allow mipsevm to use both unicorn and the evm

.github/workflows/test_challenge.yml

@@ -34,6 +34,6 @@ jobs:
         cd mipsevm
         go build
     - name: Generate checkpoints for 13284469
-      run: mipsevm/mipsevm 13284469
+      run: cd mipsevm && ./mipsevm 13284469
     - name: Run test challenge
       run: npx hardhat test test/challenge_test.js

mipsevm/main.go

@@ -26,12 +26,27 @@ func main() {
 	if len(os.Args) > 2 {
 		target, _ = strconv.Atoi(os.Args[2])
 	}
+	evm := false
+	if len(os.Args) > 3 && os.Args[3] == "evm" {
+		evm = true
+	}
 
 	// step 1, generate the checkpoints every million steps using unicorn
 	ram := make(map[uint32](uint32))
 
-	lastStep := 0
-	mu := GetHookedUnicorn(root, ram, func(step int, mu uc.Unicorn, ram map[uint32](uint32)) {
+	lastStep := 1
+	if evm {
+		ZeroRegisters(ram)
+		LoadMappedFile("../mipigo/minigeth.bin", ram, 0)
+		WriteCheckpoint(ram, "/tmp/cannon/golden.json", -1)
+		LoadMappedFile(fmt.Sprintf("%s/input", root), ram, 0x30000000)
+		RunWithRam(ram, target-1, 0, nil)
+		lastStep += target - 1
+		fn := fmt.Sprintf("%s/checkpoint_%d.json", root, lastStep)
+		WriteCheckpoint(ram, fn, lastStep)
+	} else {
+		mu := GetHookedUnicorn(root, ram, func(lstep int, mu uc.Unicorn, ram map[uint32](uint32)) {
+			step := lstep + 1
 			// this can be raised to 10,000,000 if the files are too large
 			if step%10000000 == 0 || step == target {
 				SyncRegs(mu, ram)
@@ -47,7 +62,7 @@ func main() {
 
 		ZeroRegisters(ram)
 		// not ready for golden yet
-	LoadMappedFileUnicorn(mu, "mipigo/minigeth.bin", ram, 0)
+		LoadMappedFileUnicorn(mu, "../mipigo/minigeth.bin", ram, 0)
 		WriteCheckpoint(ram, "/tmp/cannon/golden.json", -1)
 		if root == "" {
 			fmt.Println("exiting early without a block number")
@@ -59,6 +74,8 @@ func main() {
 
 		mu.Start(0, 0x5ead0004)
 		SyncRegs(mu, ram)
+	}
+
 	if target == -1 {
 		WriteCheckpoint(ram, fmt.Sprintf("%s/checkpoint_final.json", root), lastStep)
 	}

mipsevm/run_unicorn.go

@@ -20,7 +20,7 @@ func check(err error) {
 	}
 }
 
-var steps int = 1
+var steps int = 0
 var heap_start uint64 = 0
 
 func WriteBytes(fd int, bytes []byte) {