#include <u.h>#include <libc.h>#include <thread.h>#include "threadimpl.h" /* first argument goes in a register; simplest just to ignore it */static voidlaunchermips(int, void (*f)(void *arg), void *arg){	(*f)(arg);	threadexits(nil);} void_threadinitstack(Thread *t, void (*f)(void*), void *arg){	ulong *tos; 	tos = (ulong*)&t->stk[t->stksize&~7];	*--tos = (ulong)arg;	*--tos = (ulong)f;	*--tos = 0;	/* first arg to launchermips */	*--tos = 0;	/* place to store return PC */	t->sched[JMPBUFPC] = (ulong)launchermips+JMPBUFDPC;	t->sched[JMPBUFSP] = (ulong)tos;}