gdt idt init

.gdbinit

@@ -3,6 +3,7 @@
 #file mutiboot.elf
 #set architecture i386:x86-64
 #target remote :1234
+display/i $pc
 
 define xbt
     set $tid=$arg0

.vscode/launch.json

@@ -22,7 +22,8 @@
             "request": "attach",
             "name": "Attach to qemu",
             // "executable": "./multiboot.elf",
-            "executable": "./boot64.elf",
+            // "executable": "./boot64.elf",
+            "executable": "./kernel.elf",
             "target": ":1234",
             "remote": true,
             "cwd": "${workspaceRoot}",

.vscode/settings.json

@@ -1,6 +1,6 @@
 {
     "go.toolsEnvVars": {
         "GOOS": "linux",
-        "GOARCH": "386",
+        "GOARCH": "amd64",
     },
 }

kernel64/asm_amd64.s

@@ -12,3 +12,39 @@ TEXT ·rt0(SB), NOSPLIT, $0-0
 TEXT ·go_entry(SB), NOSPLIT, $0
 	JMP _rt0_amd64_linux(SB)
 
+TEXT ·sseInit(SB), NOSPLIT, $0
+	MOVL CR0, AX
+	ANDW $0xFFFB, AX
+	ORW  $0x2, AX
+	MOVL AX, CR0
+	MOVL CR4, AX
+	ORW  $3<<9, AX
+	MOVL AX, CR4
+	RET
+
+TEXT ·lgdt(SB), NOSPLIT, $0-8
+	MOVQ gdtptr+0(FP), AX
+	LGDT (AX)
+	RET
+
+TEXT ·lidt(SB), NOSPLIT, $0-8
+	MOVQ idtptr+0(FP), AX
+	LIDT (AX)
+	RET
+
+TEXT ·reloadCS(SB), NOSPLIT, $0
+	// save ip
+	MOVQ 0(SP), AX
+	// save sp
+	MOVQ SP, BX
+	ADDQ $8, BX
+
+	// rerange the stack, as in an interrupt stack
+	PUSHQ $0x10 // SS
+	PUSHQ BX
+	PUSHFQ
+	PUSHQ $8
+	PUSHQ AX
+
+	// IRET
+	IRETQ

kernel64/genvector.go

@@ -0,0 +1,65 @@
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"log"
+)
+
+func hasErrCode(idx int) bool {
+	return idx == 8 || (idx >= 10 && idx <= 14) || idx == 17
+}
+
+func genasm() {
+	buf := new(bytes.Buffer)
+	buf.WriteString("// Code generated by genvector.go using 'go generate'. DO NOT EDIT.\n")
+	buf.WriteString(`#include "textflag.h"`)
+	buf.WriteString("\n\n")
+	for i := 0; i < 256; i++ {
+		fmt.Fprintf(buf, "TEXT ·trap%d(SB), NOSPLIT, $0-0\n", i)
+		if !hasErrCode(i) {
+			buf.WriteString("  PUSHQ    $0\n")
+		}
+		fmt.Fprintf(buf, "  PUSHQ    $%d\n", i)
+		buf.WriteString("  JMP    alltraps(SB)\n")
+		buf.WriteString("  POPQ    AX\n")
+		if !hasErrCode(i) {
+			buf.WriteString("  POPQ    AX\n")
+		}
+		buf.WriteString("  RET\n\n")
+	}
+	err := ioutil.WriteFile("vectors.s", buf.Bytes(), 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func gengo() {
+	buf := new(bytes.Buffer)
+	buf.WriteString("// Code generated by genvector.go using 'go generate'. DO NOT EDIT.\n")
+	buf.WriteString("package kernel64\n\n")
+	for i := 0; i < 256; i++ {
+		fmt.Fprintf(buf, "//go:nosplit\n")
+		fmt.Fprintf(buf, "func trap%d()\n", i)
+	}
+	buf.WriteString("\n")
+
+	buf.WriteString("var vectors = [...]func(){\n")
+	for i := 0; i < 256; i++ {
+		fmt.Fprintf(buf, "trap%d,\n", i)
+	}
+	buf.WriteString("}\n\n")
+
+	err := ioutil.WriteFile("vectors.go", buf.Bytes(), 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func main() {
+	genasm()
+	gengo()
+}

kernel64/preinit.go

@@ -8,8 +8,15 @@ func rt0()
 //go:nosplit
 func go_entry()
 
+//go:nosplit
+func sseInit()
+
 //go:nosplit
 func preinit() {
+	sseInit()
+	gdtInit()
+	idtInit()
+	uart.PreInit()
 	uart.WriteString("kernel64\n")
 	go_entry()
 	for {

kernel64/seg_amd64.go

@@ -0,0 +1,89 @@
+package kernel64
+
+import (
+	"unsafe"
+
+	"github.com/icexin/eggos/sys"
+)
+
+const (
+	segDplKernel = 0x00
+	segDplUser   = 0x60
+)
+
+var (
+	gdt    [5]gdtSegDesc
+	gdtptr [10]byte
+
+	idt    [256]idtSetDesc
+	idtptr [10]byte
+)
+
+type gdtSegDesc [8]byte
+
+type idtSetDesc struct {
+	Addr1    uint16
+	Selector uint16
+	Attr     uint16
+	Addr2    uint16
+	Addr3    uint32
+	Reserved uint32
+}
+
+//go:nosplit
+func lgdt(gdtptr uintptr)
+
+//go:nosplit
+func lidt(idtptr uintptr)
+
+//go:nosplit
+func reloadCS()
+
+//go:nosplit
+func setGdtCodeDesc(desc *gdtSegDesc, dpl uint8) {
+	desc[5] |= dpl | 0x98 // P=1 C=0
+	desc[6] |= 0x20       // D=0 L=1
+}
+
+//go:nosplit
+func setGdtDataDesc(desc *gdtSegDesc, dpl uint8) {
+	desc[5] |= dpl | 0x92 // P=1 W=1
+}
+
+//go:nosplit
+func gdtInit() {
+	// leave gdt[0] untouch
+	setGdtCodeDesc(&gdt[1], segDplKernel)
+	setGdtDataDesc(&gdt[2], segDplKernel)
+	setGdtCodeDesc(&gdt[3], segDplUser)
+	setGdtDataDesc(&gdt[4], segDplUser)
+
+	limit := (*uint16)(unsafe.Pointer(&gdtptr[0]))
+	base := (*uint64)(unsafe.Pointer(&gdtptr[2]))
+	*limit = uint16(unsafe.Sizeof(gdt) - 1)
+	*base = uint64(uintptr(unsafe.Pointer(&gdt[0])))
+	lgdt(uintptr(unsafe.Pointer(&gdtptr[0])))
+	reloadCS()
+}
+
+//go:nosplit
+func setIdtDesc(desc *idtSetDesc, addr uintptr) {
+	desc.Addr1 = uint16(addr & 0xffff)
+	desc.Selector = 8
+	desc.Attr = 0x8e00 // P=1 TYPE=e interrupt gate
+	desc.Addr2 = uint16(addr >> 16 & 0xffff)
+	desc.Addr3 = uint32(addr>>32) & 0xffffffff
+}
+
+//go:nosplit
+func idtInit() {
+	for i := 0; i < 256; i++ {
+		setIdtDesc(&idt[i], sys.FuncPC(vectors[i]))
+	}
+
+	limit := (*uint16)(unsafe.Pointer(&idtptr[0]))
+	base := (*uint64)(unsafe.Pointer(&idtptr[2]))
+	*limit = uint16(unsafe.Sizeof(idt) - 1)
+	*base = uint64(uintptr(unsafe.Pointer(&idt[0])))
+	lidt(uintptr(unsafe.Pointer(&idtptr)))
+}

kernel64/trap.go

@@ -0,0 +1,23 @@
+package kernel64
+
+import "github.com/icexin/eggos/uart"
+
+type trapFrame struct {
+	AX, BX, CX, DX    uintptr
+	BP, SI, DI, R8    uintptr
+	R9, R10, R11, R12 uintptr
+	R13, R14, R15     uintptr
+
+	Trapno, Err uintptr
+
+	// pushed by hardward
+	IP, CS, FLAGS, SP, SS uintptr
+}
+
+//go:nosplit
+func trapret()
+
+//go:nosplit
+func dotrap(tf *trapFrame) {
+	uart.WriteString("trap\n")
+}

kernel64/trap.s

@@ -0,0 +1,45 @@
+#include "textflag.h"
+
+TEXT alltraps(SB), NOSPLIT, $0
+    PUSHQ R15
+    PUSHQ R14
+    PUSHQ R13
+    PUSHQ R12
+    PUSHQ R11
+    PUSHQ R10
+    PUSHQ R9
+    PUSHQ R8
+    PUSHQ DI
+    PUSHQ SI
+    PUSHQ BP
+    PUSHQ DX
+    PUSHQ CX
+    PUSHQ BX
+    PUSHQ AX
+
+    PUSHQ SP
+    CALL  ·dotrap(SB)
+	ADDQ  $8, SP
+	JMP   ·trapret(SB)
+
+TEXT ·trapret(SB), NOSPLIT, $0
+    POPQ AX
+    POPQ BX
+    POPQ CX
+    POPQ DX
+    POPQ BP
+    POPQ SI
+    POPQ DI
+    POPQ R8
+    POPQ R9
+    POPQ R10
+    POPQ R11
+    POPQ R12
+    POPQ R13
+    POPQ R14
+    POPQ R15
+
+	ADDL $16, SP // skip trapno and errcode
+
+    IRETQ
+