#define	setcontext(u)	_setmcontext(&(u)->mc)#define	getcontext(u)	_getmcontext(&(u)->mc)typedef struct mcontext mcontext_t;typedef struct ucontext ucontext_t;struct mcontext{	ulong	pc;		/* lr */	ulong	cr;		/* mfcr */	ulong	ctr;		/* mfcr */	ulong	xer;		/* mfcr */	ulong	sp;		/* callee saved: r1 */	ulong	toc;		/* callee saved: r2 */	ulong	r3;		/* first arg to function, return register: r3 */	ulong	gpr[19];	/* callee saved: r13-r31 *//*// XXX: currently do not save vector registers or floating-point state//	ulong	pad;//	uvlong	fpr[18];	/ * callee saved: f14-f31 * ///	ulong	vr[4*12];	/ * callee saved: v20-v31, 256-bits each * /*/}; struct ucontext{	struct {		void *ss_sp;		uint ss_size;	} uc_stack;	sigset_t uc_sigmask;	mcontext_t mc;}; void makecontext(ucontext_t*, void(*)(void), int, ...);int swapcontext(ucontext_t*, ucontext_t*);int _getmcontext(mcontext_t*);void _setmcontext(mcontext_t*);