src: Add support for 64-bit version of Plan 9
This set of changes extends the Plan 9 support
to include the AMD64 architecture and should
work on all versions of Plan 9.
R=golang-dev, rminnich, noah.evans, rsc, minux.ma, npe
CC=akskuma, golang-dev, jfflore, noah.evans
https://golang.org/cl/6479052
diff --git a/src/pkg/runtime/sys_plan9_amd64.s b/src/pkg/runtime/sys_plan9_amd64.s
new file mode 100644
index 0000000..cc343d1
--- /dev/null
+++ b/src/pkg/runtime/sys_plan9_amd64.s
@@ -0,0 +1,124 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "defs_GOOS_GOARCH.h"
+#include "zasm_GOOS_GOARCH.h"
+
+// setldt(int entry, int address, int limit)
+TEXT runtime·setldt(SB),7,$0
+ RET
+
+TEXT runtime·open(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $14, BP
+ SYSCALL
+ RET
+
+TEXT runtime·pread(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $50, BP
+ SYSCALL
+ RET
+
+TEXT runtime·pwrite(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $51, BP
+ SYSCALL
+ RET
+
+TEXT runtime·close(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $4, BP
+ SYSCALL
+ RET
+
+TEXT runtime·exits(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $8, BP
+ SYSCALL
+ RET
+
+TEXT runtime·brk_(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $24, BP
+ SYSCALL
+ RET
+
+TEXT runtime·sleep(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $17, BP
+ SYSCALL
+ RET
+
+TEXT runtime·plan9_semacquire(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $37, BP
+ SYSCALL
+ RET
+
+TEXT runtime·plan9_tsemacquire(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $52, BP
+ SYSCALL
+ RET
+
+TEXT runtime·notify(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $28, BP
+ SYSCALL
+ RET
+
+TEXT runtime·noted(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $29, BP
+ SYSCALL
+ RET
+
+TEXT runtime·plan9_semrelease(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $38, BP
+ SYSCALL
+ RET
+
+TEXT runtime·rfork(SB),7,$0
+ MOVQ $0x8000, AX
+ MOVQ $19, BP // rfork
+ SYSCALL
+
+ // In parent, return.
+ CMPQ AX, $0
+ JEQ 2(PC)
+ RET
+
+ // In child on forked stack.
+ MOVQ mm+24(SP), BX // m
+ MOVQ gg+32(SP), DX // g
+ MOVQ fn+40(SP), SI // fn
+
+ // set SP to be on the new child stack
+ MOVQ stack+16(SP), CX
+ MOVQ CX, SP
+
+ // Initialize m, g.
+ get_tls(AX)
+ MOVQ DX, g(AX)
+ MOVQ BX, m(AX)
+
+ // Initialize AX from _tos->pid
+ MOVQ _tos(SB), AX
+ MOVQ tos_pid(AX), AX
+ MOVQ AX, m_procid(BX) // save pid as m->procid
+
+ CALL runtime·stackcheck(SB) // smashes AX, CX
+
+ MOVQ 0(DX), DX // paranoia; check they are not nil
+ MOVQ 0(BX), BX
+
+ CALL SI // fn()
+ CALL runtime·exit(SB)
+ RET
+
+// This is needed by asm_amd64.s
+TEXT runtime·settls(SB),7,$0
+ RET
