Add some RAM and a stack

gb/ram.go

@@ -0,0 +1,55 @@
+package gb
+
+import (
+	"fmt"
+	"os"
+)
+
+type RAM struct {
+	WRAM [0x2000]byte
+	HRAM [0x80]byte
+}
+
+func NewRAM() *RAM {
+	ram := RAM{}
+
+	return &ram
+}
+
+func (ram *RAM) WRAMRead(address uint16) byte {
+	// TODO(m): Understand this line
+	address -= 0xC000
+
+	if address >= 0x2000 {
+		fmt.Printf("Reading from WRAM: invalid address %X", address+0xC000)
+		os.Exit(1)
+	}
+
+	return ram.WRAM[address]
+}
+
+func (ram *RAM) WRAMWrite(address uint16, value byte) {
+	// TODO(m): Understand this line
+	address -= 0xC000
+
+	if address >= 0x2000 {
+		fmt.Printf("Writing to WRAM: invalid address %X", address)
+		os.Exit(1)
+	}
+
+	ram.WRAM[address] = value
+}
+
+func (ram *RAM) HRAMRead(address uint16) byte {
+	// TODO(m): Understand this line
+	address -= 0xFF80
+
+	return ram.HRAM[address]
+}
+
+func (ram *RAM) HRAMWrite(address uint16, value byte) {
+	// TODO(m): Understand this line
+	address -= 0xFF80
+
+	ram.HRAM[address] = value
+}