8l, runtime: place G and M pointers relative to _tos on Plan 9, instead of hardcoded values for USTKTOP.
This should allow executing both on native Plan 9 and inside 9vx.
R=rsc
CC=golang-dev
https://golang.org/cl/3993044
diff --git a/src/pkg/runtime/plan9/386/sys.s b/src/pkg/runtime/plan9/386/sys.s
index 867b894..f760b78 100644
--- a/src/pkg/runtime/plan9/386/sys.s
+++ b/src/pkg/runtime/plan9/386/sys.s
@@ -58,9 +58,10 @@
MOVL BX, m(AX)
// Initialize AX from _tos->pid
- MOVL 0xdfffeff8, AX
+ MOVL _tos(SB), AX
+ MOVL tos_pid(AX), AX
MOVL AX, m_procid(BX) // save pid as m->procid
-
+
CALL runtime·stackcheck(SB) // smashes AX, CX
MOVL 0(DX), DX // paranoia; check they are not nil
