init

1 files changed, 19 insertions, 0 deletions

diff --git a/vm/rom.go b/vm/rom.go
new file mode 100644
index 0000000..958e70e
--- /dev/null
+++ b/vm/rom.go
@@ -0,0 +1,19 @@
+package main 
+
+import (
+	 "os"
+	 "fmt"
+)
+
+type Rom []byte
+
+func (r *Rom) Fetch(pc *uint64, n uint64) []byte {
+	if (*pc + n > uint64(len(*r)) - 1) {
+		fmt.Fprintf(os.Stderr, "error: trying to read outside of rom\n")
+		os.Exit(1)
+	}
+	x := make([]byte, n)
+	copy(x, (*r)[*pc:*pc + n])
+	*pc += n
+	return x
+}