cmd/7l: add the ARM64 linker

Only internal linking without cgo is supported for now.

Change-Id: I91eb1572c1ccc805db62fc4c29080df98797d51a
Reviewed-on: https://go-review.googlesource.com/7048Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

src/cmd/7l/l.go

@@ -62,7 +62,7 @@ package main
 // THE SOFTWARE.
 
 const (
-	thechar   = '9'
+	thechar   = '7'
 	PtrSize   = 8
 	IntSize   = 8
 	RegSize   = 8
@@ -73,5 +73,5 @@ const (
 
 /* Used by ../ld/dwarf.c */
 const (
-	DWARFREGSP = 1
+	DWARFREGSP = 31
 )

src/cmd/7l/obj.go

@@ -46,11 +46,7 @@ func main() {
 
 func linkarchinit() {
 	ld.Thestring = obj.Getgoarch()
-	if ld.Thestring == "ppc64le" {
-		ld.Thelinkarch = &ld.Linkppc64le
-	} else {
-		ld.Thelinkarch = &ld.Linkppc64
-	}
+	ld.Thelinkarch = &ld.Linkarm64
 
 	ld.Thearch.Thechar = thechar
 	ld.Thearch.Ptrsize = ld.Thelinkarch.Ptrsize
@@ -72,18 +68,11 @@ func linkarchinit() {
 	ld.Thearch.Elfsetupplt = elfsetupplt
 	ld.Thearch.Gentext = gentext
 	ld.Thearch.Machoreloc1 = machoreloc1
-	if ld.Thelinkarch == &ld.Linkppc64le {
-		ld.Thearch.Lput = ld.Lputl
-		ld.Thearch.Wput = ld.Wputl
-		ld.Thearch.Vput = ld.Vputl
-	} else {
-		ld.Thearch.Lput = ld.Lputb
-		ld.Thearch.Wput = ld.Wputb
-		ld.Thearch.Vput = ld.Vputb
-	}
+	ld.Thearch.Lput = ld.Lputl
+	ld.Thearch.Wput = ld.Wputl
+	ld.Thearch.Vput = ld.Vputl
 
-	// TODO(austin): ABI v1 uses /usr/lib/ld.so.1
-	ld.Thearch.Linuxdynld = "/lib64/ld64.so.1"
+	ld.Thearch.Linuxdynld = "/lib/ld-linux-aarch64.so.1"
 
 	ld.Thearch.Freebsddynld = "XXX"
 	ld.Thearch.Openbsddynld = "XXX"
@@ -129,9 +118,7 @@ func archinit() {
 		}
 
 	case ld.Hlinux: /* ppc64 elf */
-		if ld.Thestring == "ppc64" {
-			ld.Debug['d'] = 1 // TODO(austin): ELF ABI v1 not supported yet
-		}
+		ld.Debug['d'] = 1 // TODO(aram): dynamic linking is not supported yet.
 		ld.Elfinit()
 		ld.HEADR = ld.ELFRESERVE
 		if ld.INITTEXT == -1 {

src/cmd/internal/ld/arch.go

@@ -15,6 +15,15 @@ var Linkarm = LinkArch{
 	Regsize:   4,
 }
 
+var Linkarm64 = LinkArch{
+	ByteOrder: binary.LittleEndian,
+	Name:      "arm64",
+	Thechar:   '7',
+	Minlc:     4,
+	Ptrsize:   8,
+	Regsize:   8,
+}
+
 var Linkamd64 = LinkArch{
 	ByteOrder: binary.LittleEndian,
 	Name:      "amd64",

src/cmd/internal/ld/elf.go

@@ -164,6 +164,7 @@ const (
 	EM_ST100             = 60
 	EM_TINYJ             = 61
 	EM_X86_64            = 62
+	EM_AARCH64           = 183
 	EM_486               = 6
 	EM_MIPS_RS4_BE       = 10
 	EM_ALPHA_STD         = 41
@@ -344,6 +345,9 @@ const (
 	R_X86_64_GOTTPOFF      = 22
 	R_X86_64_TPOFF32       = 23
 	R_X86_64_COUNT         = 24
+	R_AARCH64_ABS64        = 257
+	R_AARCH64_ABS32        = 258
+	R_AARCH64_CALL26       = 283
 	R_ALPHA_NONE           = 0
 	R_ALPHA_REFLONG        = 1
 	R_ALPHA_REFQUAD        = 2
@@ -757,8 +761,7 @@ func Elfinit() {
 		}
 		fallthrough
 
-		// fallthrough
-	case '6':
+	case '6', '7':
 		elf64 = 1
 
 		ehdr.phoff = ELF64HDRSIZE      /* Must be be ELF64HDRSIZE: first PHdr must follow ELF header */
@@ -1367,14 +1370,15 @@ func elfdynhash() {
 		elfwritedynentsym(s, DT_VERSYM, Linklookup(Ctxt, ".gnu.version", 0))
 	}
 
-	if Thearch.Thechar == '6' || Thearch.Thechar == '9' {
+	switch Thearch.Thechar {
+	case '6', '7', '9':
 		sy := Linklookup(Ctxt, ".rela.plt", 0)
 		if sy.Size > 0 {
 			Elfwritedynent(s, DT_PLTREL, DT_RELA)
 			elfwritedynentsymsize(s, DT_PLTRELSZ, sy)
 			elfwritedynentsym(s, DT_JMPREL, sy)
 		}
-	} else {
+	default:
 		sy := Linklookup(Ctxt, ".rel.plt", 0)
 		if sy.Size > 0 {
 			Elfwritedynent(s, DT_PLTREL, DT_REL)
@@ -1627,7 +1631,8 @@ func doelf() {
 		Debug['s'] = 0
 		Debug['d'] = 1
 
-		if Thearch.Thechar == '6' || Thearch.Thechar == '9' {
+		switch Thearch.Thechar {
+		case '6', '7', '9':
 			Addstring(shstrtab, ".rela.text")
 			Addstring(shstrtab, ".rela.rodata")
 			Addstring(shstrtab, ".rela.typelink")
@@ -1635,7 +1640,8 @@ func doelf() {
 			Addstring(shstrtab, ".rela.gopclntab")
 			Addstring(shstrtab, ".rela.noptrdata")
 			Addstring(shstrtab, ".rela.data")
-		} else {
+
+		default:
 			Addstring(shstrtab, ".rel.text")
 			Addstring(shstrtab, ".rel.rodata")
 			Addstring(shstrtab, ".rel.typelink")
@@ -1711,9 +1717,10 @@ func doelf() {
 		dynstr := s
 
 		/* relocation table */
-		if Thearch.Thechar == '6' || Thearch.Thechar == '9' {
+		switch Thearch.Thechar {
+		case '6', '7', '9':
 			s = Linklookup(Ctxt, ".rela", 0)
-		} else {
+		default:
 			s = Linklookup(Ctxt, ".rel", 0)
 		}
 		s.Reachable = true
@@ -1755,9 +1762,10 @@ func doelf() {
 
 		Thearch.Elfsetupplt()
 
-		if Thearch.Thechar == '6' || Thearch.Thechar == '9' {
+		switch Thearch.Thechar {
+		case '6', '7', '9':
 			s = Linklookup(Ctxt, ".rela.plt", 0)
-		} else {
+		default:
 			s = Linklookup(Ctxt, ".rel.plt", 0)
 		}
 		s.Reachable = true
@@ -1790,11 +1798,12 @@ func doelf() {
 		}
 		elfwritedynentsym(s, DT_STRTAB, Linklookup(Ctxt, ".dynstr", 0))
 		elfwritedynentsymsize(s, DT_STRSZ, Linklookup(Ctxt, ".dynstr", 0))
-		if Thearch.Thechar == '6' || Thearch.Thechar == '9' {
+		switch Thearch.Thechar {
+		case '6', '7', '9':
 			elfwritedynentsym(s, DT_RELA, Linklookup(Ctxt, ".rela", 0))
 			elfwritedynentsymsize(s, DT_RELASZ, Linklookup(Ctxt, ".rela", 0))
 			Elfwritedynent(s, DT_RELAENT, ELF64RELASIZE)
-		} else {
+		default:
 			elfwritedynentsym(s, DT_REL, Linklookup(Ctxt, ".rel", 0))
 			elfwritedynentsymsize(s, DT_RELSZ, Linklookup(Ctxt, ".rel", 0))
 			Elfwritedynent(s, DT_RELENT, ELF32RELSIZE)
@@ -1870,6 +1879,9 @@ func Asmbelf(symo int64) {
 	case '6':
 		eh.machine = EM_X86_64
 
+	case '7':
+		eh.machine = EM_AARCH64
+
 	case '8':
 		eh.machine = EM_386
 
@@ -2033,7 +2045,8 @@ func Asmbelf(symo int64) {
 
 		switch eh.machine {
 		case EM_X86_64,
-			EM_PPC64:
+			EM_PPC64,
+			EM_AARCH64:
 			sh := elfshname(".rela.plt")
 			sh.type_ = SHT_RELA
 			sh.flags = SHF_ALLOC

src/cmd/internal/ld/ldelf.go

@@ -84,6 +84,7 @@ const (
 	ElfMachSH          = 42
 	ElfMachSparc9      = 43
 	ElfMachAmd64       = 62
+	ElfMachArm64       = 183
 )
 
 const (
@@ -432,6 +433,12 @@ func ldelf(f *Biobuf, pkg string, length int64, pn string) {
 			return
 		}
 
+	case '7':
+		if e != binary.LittleEndian || elfobj.machine != ElfMachArm64 || hdr.Ident[4] != ElfClass64 {
+			Diag("%s: elf object but not arm64", pn)
+			return
+		}
+
 	case '8':
 		if e != binary.LittleEndian || elfobj.machine != ElfMach386 || hdr.Ident[4] != ElfClass32 {
 			Diag("%s: elf object but not 386", pn)

src/cmd/internal/ld/lib.go

@@ -1064,7 +1064,7 @@ var (
 // allow stack checks here.
 
 func haslinkregister() bool {
-	return Thearch.Thechar == '5' || Thearch.Thechar == '9'
+	return Thearch.Thechar == '5' || Thearch.Thechar == '9' || Thearch.Thechar == '7'
 }
 
 func callsize() int {
@@ -1183,6 +1183,7 @@ func stkcheck(up *Chain, depth int) int {
 			// Direct call.
 			case R_CALL,
 				R_CALLARM,
+				R_CALLARM64,
 				R_CALLPOWER:
 				ch.limit = int(int32(limit) - pcsp.value - int32(callsize()))
 

src/cmd/internal/ld/link.go

@@ -219,6 +219,7 @@ const (
 	R_SIZE
 	R_CALL
 	R_CALLARM
+	R_CALLARM64
 	R_CALLIND
 	R_CALLPOWER
 	R_CONST

src/cmd/internal/ld/symtab.go

@@ -58,6 +58,7 @@ func putelfstr(s string) int {
 func putelfsyment(off int, addr int64, size int64, info int, shndx int, other int) {
 	switch Thearch.Thechar {
 	case '6',
+		'7',
 		'9':
 		Thearch.Lput(uint32(off))
 		Cput(uint8(info))