--- /dev/null
+// Copyright 2009 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 "runtime.h"
+
+static int32 debug = 0;
+
+void
+sys·goexit(void)
+{
+//prints("goexit goid=");
+//sys·printint(g->goid);
+//prints("\n");
+ g->status = Gdead;
+ sys·gosched();
+}
+
+void
+sys·newproc(int32 siz, byte* fn, byte* arg0)
+{
+ byte *stk, *sp;
+ G *newg;
+
+//prints("newproc siz=");
+//sys·printint(siz);
+//prints(" fn=");
+//sys·printpointer(fn);
+
+ siz = (siz+7) & ~7;
+ if(siz > 1024) {
+ prints("sys·newproc: too many args: ");
+ sys·printint(siz);
+ prints("\n");
+ sys·panicl(123);
+ }
+
+ newg = mal(sizeof(G));
+ stk = mal(4096);
+ newg->stackguard = stk+160;
+
+ sp = stk + 4096 - 4*8;
+ newg->stackbase = sp;
+
+ sp -= siz;
+ mcpy(sp, (byte*)&arg0, siz);
+
+ sp -= 8;
+ *(byte**)sp = (byte*)sys·goexit;
+
+ sp -= 8; // retpc used by gogo
+ newg->sched.SP = sp;
+ newg->sched.PC = fn;
+
+ goidgen++;
+ newg->goid = goidgen;
+
+ newg->status = Grunnable;
+ newg->alllink = allg;
+ allg = newg;
+
+//prints(" goid=");
+//sys·printint(newg->goid);
+//prints("\n");
+}
+
+G*
+select(void)
+{
+ G *gp, *bestg;
+
+ bestg = nil;
+ for(gp=allg; gp!=nil; gp=gp->alllink) {
+ if(gp->status != Grunnable)
+ continue;
+ if(bestg == nil || gp->pri < bestg->pri)
+ bestg = gp;
+ }
+ if(bestg != nil)
+ bestg->pri++;
+ return bestg;
+}
+
+void
+gom0init(void)
+{
+ gosave(&m->sched);
+ sys·gosched();
+}
+
+void
+sys·gosched(void)
+{
+ G* gp;
+
+ if(g != m->g0) {
+ if(gosave(&g->sched))
+ return;
+ g = m->g0;
+ gogo(&m->sched);
+ }
+ gp = select();
+ if(gp == nil) {
+// prints("sched: no more work\n");
+ sys·exit(0);
+ }
+
+ m->curg = gp;
+ g = gp;
+ gogo(&gp->sched);
+}
+
+//
+// the calling sequence for a routine that
+// needs N bytes stack, A args.
+//
+// N1 = (N+160 > 4096)? N+160: 0
+// A1 = A
+//
+// if N <= 75
+// CMPQ SP, 0(R15)
+// JHI 4(PC)
+// MOVQ $(N1<<0) | (A1<<32)), AX
+// MOVQ AX, 0(R14)
+// CALL sys·morestack(SB)
+//
+// if N > 75
+// LEAQ (-N-75)(SP), AX
+// CMPQ AX, 0(R15)
+// JHI 4(PC)
+// MOVQ $(N1<<0) | (A1<<32)), AX
+// MOVQ AX, 0(R14)
+// CALL sys·morestack(SB)
+//
+
+void
+oldstack(void)
+{
+ Stktop *top;
+ uint32 siz2;
+ byte *sp;
+
+// prints("oldstack m->cret = ");
+// sys·printpointer((void*)m->cret);
+// prints("\n");
+
+ top = (Stktop*)m->curg->stackbase;
+
+ m->curg->stackbase = top->oldbase;
+ m->curg->stackguard = top->oldguard;
+ siz2 = (top->magic>>32) & 0xffffLL;
+
+ sp = (byte*)top;
+ if(siz2 > 0) {
+ siz2 = (siz2+7) & ~7;
+ sp -= siz2;
+ mcpy(top->oldsp+16, sp, siz2);
+ }
+
+ m->morestack.SP = top->oldsp+8;
+ m->morestack.PC = (byte*)(*(uint64*)(top->oldsp+8));
+
+// prints("oldstack sp=");
+// sys·printpointer(m->morestack.SP);
+// prints(" pc=");
+// sys·printpointer(m->morestack.PC);
+// prints("\n");
+
+ gogoret(&m->morestack, m->cret);
+}
+
+void
+newstack(void)
+{
+ int32 siz1, siz2;
+ Stktop *top;
+ byte *stk, *sp;
+ void (*fn)(void);
+
+ siz1 = m->morearg & 0xffffffffLL;
+ siz2 = (m->morearg>>32) & 0xffffLL;
+
+// prints("newstack siz1=");
+// sys·printint(siz1);
+// prints(" siz2=");
+// sys·printint(siz2);
+// prints(" moresp=");
+// sys·printpointer(m->moresp);
+// prints("\n");
+
+ if(siz1 < 4096)
+ siz1 = 4096;
+ stk = mal(siz1 + 1024);
+ stk += 512;
+
+ top = (Stktop*)(stk+siz1-sizeof(*top));
+
+ top->oldbase = m->curg->stackbase;
+ top->oldguard = m->curg->stackguard;
+ top->oldsp = m->moresp;
+ top->magic = m->morearg;
+
+ m->curg->stackbase = (byte*)top;
+ m->curg->stackguard = stk + 160;
+
+ sp = (byte*)top;
+
+ if(siz2 > 0) {
+ siz2 = (siz2+7) & ~7;
+ sp -= siz2;
+ mcpy(sp, m->moresp+16, siz2);
+ }
+
+ g = m->curg;
+ fn = (void(*)(void))(*(uint64*)m->moresp);
+
+// prints("fn=");
+// sys·printpointer(fn);
+// prints("\n");
+
+ setspgoto(sp, fn, retfromnewstack);
+
+ *(int32*)345 = 123; // never return
+}
+
+void
+sys·morestack(uint64 u)
+{
+ while(g == m->g0) {
+ // very bad news
+ *(int32*)123 = 123;
+ }
+
+ g = m->g0;
+ m->moresp = (byte*)(&u-1);
+ setspgoto(m->sched.SP, newstack, nil);
+
+ *(int32*)234 = 123; // never return
+}
+
+G*
+dequeue(WaitQ *q)
+{
+ G *gp;
+
+ gp = q->first;
+ if(gp == nil)
+ return nil;
+ q->first = gp->qlink;
+ return gp;
+}
+
+void
+enqueue(WaitQ *q, G *gp)
+{
+ gp->qlink = nil;
+ if(q->first == nil) {
+ q->first = gp;
+ q->last = gp;
+ return;
+ }
+ q->last->qlink = gp;
+ q->last = gp;
+}