Added memory address patching

src/asm/Assembler.go

@@ -1,37 +1,78 @@
 package asm
 
 import (
+	"bytes"
+	"encoding/binary"
+
+	"git.akyoto.dev/cli/q/src/asm/x64"
+	"git.akyoto.dev/cli/q/src/config"
+	"git.akyoto.dev/cli/q/src/log"
 	"git.akyoto.dev/cli/q/src/register"
 )
 
 // Assembler contains a list of instructions.
 type Assembler struct {
 	instructions []Instruction
-	labels       map[string]int
+	labels       map[string]Index
+	verbose      bool
 }
 
 // New creates a new assembler.
 func New() *Assembler {
 	return &Assembler{
 		instructions: make([]Instruction, 0, 8),
-		labels:       map[string]int{},
+		labels:       map[string]Index{},
+		verbose:      true,
 	}
 }
 
 // Finalize generates the final machine code.
 func (a *Assembler) Finalize() *Result {
-	final := Result{}
+	result := &Result{}
+	pointers := map[Address]Address{}
+	code := bytes.NewBuffer(result.Code)
 
-	for _, instr := range a.instructions {
-		instr.Write(&final.Code)
+	for _, x := range a.instructions {
+		if a.verbose {
+			log.Info.Println(x.String())
+		}
+
+		switch x.Mnemonic {
+		case MOV:
+			x64.MoveRegNum32(code, uint8(x.Destination), uint32(x.Number))
+
+		case MOVDATA:
+			position := result.AddData(x.Data)
+			x64.MoveRegNum32(code, uint8(x.Destination), 0)
+			pointers[Address(code.Len()-4)] = position
+
+		case SYSCALL:
+			x64.Syscall(code)
+		}
 	}
 
-	return &final
+	result.Code = code.Bytes()
+	dataStart := config.BaseAddress + config.CodeOffset + Address(len(result.Code))
+
+	for codePos, dataPos := range pointers {
+		binary.LittleEndian.PutUint32(result.Code[codePos:codePos+4], dataStart+dataPos)
+	}
+
+	return result
 }
 
 // AddLabel creates a new label at the current position.
 func (a *Assembler) AddLabel(name string) {
-	a.labels[name] = len(a.instructions)
+	a.labels[name] = Index(len(a.instructions))
+}
+
+// MoveRegisterData moves a data section address into the given register.
+func (a *Assembler) MoveRegisterData(reg register.ID, data []byte) {
+	a.instructions = append(a.instructions, Instruction{
+		Mnemonic:    MOVDATA,
+		Destination: reg,
+		Data:        data,
+	})
 }
 
 // MoveRegisterNumber moves a number into the given register.