func (c *sigctxt) rsp() uint64 { return c.regs().__gregs[_REG_RSP] }
func (c *sigctxt) r8() uint64  { return c.regs().__gregs[_REG_R8] }
func (c *sigctxt) r9() uint64  { return c.regs().__gregs[_REG_R9] }
func (c *sigctxt) r10() uint64 { return c.regs().__gregs[_REG_R10] }
func (c *sigctxt) r11() uint64 { return c.regs().__gregs[_REG_R11] }
func (c *sigctxt) r12() uint64 { return c.regs().__gregs[_REG_R12] }

	// Machine dependent mcontext initialisation for LWP.
	mc.__gregs[_REG_R15] = uint32(abi.FuncPCABI0(lwp_tramp))
	mc.__gregs[_REG_R13] = uint32(uintptr(stk))
	mc.__gregs[_REG_R0] = uint32(uintptr(unsafe.Pointer(mp)))
	mc.__gregs[_REG_R1] = uint32(uintptr(unsafe.Pointer(gp)))
	mc.__gregs[_REG_R2] = uint32(fn)
}

func checkgoarm() {
	// TODO(minux): FP checks like in os_linux_arm.go.

	// Machine dependent mcontext initialisation for LWP.
	mc.__gregs[_REG_ELR] = uint64(abi.FuncPCABI0(lwp_tramp))
	mc.__gregs[_REG_X31] = uint64(uintptr(stk))
	mc.__gregs[_REG_X0] = uint64(uintptr(unsafe.Pointer(mp)))
	mc.__gregs[_REG_X1] = uint64(uintptr(unsafe.Pointer(mp.g0)))
	mc.__gregs[_REG_X2] = uint64(fn)
}

//go:nosplit
func cputicks() int64 {

	_       [4]byte // EABI
}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = x
}

type itimerval struct {
	it_interval timeval
	it_value    timeval
}

type mcontextt struct {
	__gregs     [17]uint32
	_           [4]byte   // EABI
	__fpu       [272]byte // EABI
	_mc_tlsbase uint32
	_           [4]byte // EABI
}

type ucontextt struct {
	uc_flags    uint32
	uc_link     *ucontextt

}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = x
}

type itimerval struct {
	it_interval timeval
	it_value    timeval
}

type mcontextt struct {
	__gregs [35]uint64
	__fregs [4160]byte // _NFREG * 128 + 32 + 32
	_       [8]uint64  // future use
}

type ucontextt struct {
	uc_flags    uint32
	uc_link     *ucontextt
	uc_sigmask  sigset
	uc_stack    stackt

}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = x
}

type itimerval struct {
	it_interval timeval
	it_value    timeval
}

type mcontextt struct {
	__gregs     [19]uint32
	__fpregs    [644]byte
	_mc_tlsbase int32
}

type ucontextt struct {
	uc_flags    uint32
	uc_link     *ucontextt
	uc_sigmask  sigset
	uc_stack    stackt
	uc_mcontext mcontextt

}

func (tv *timeval) set_usec(x int32) {
	tv.tv_usec = x
}

type itimerval struct {
	it_interval timeval
	it_value    timeval
}

type mcontextt struct {
	__gregs     [26]uint64
	_mc_tlsbase uint64
	__fpregs    [512]int8
}

type ucontextt struct {
	uc_flags    uint32
	pad_cgo_0   [4]byte
	uc_link     *ucontextt
	uc_sigmask  sigset
	uc_stack    stackt
	uc_mcontext mcontextt

	si_errno  int32
	si_code   int32
	si_pid    int32
	si_uid    uint32
	si_status int32
	si_addr   uintptr
	si_value  [4]byte
	_reason   [32]byte
}

type mcontext struct {
	__gregs [17]uint32
	__fpu   [140]byte
}

type ucontext struct {
	uc_sigmask  sigset
	uc_mcontext mcontext
	uc_link     *ucontext
	uc_stack    stackt
	uc_flags    int32
	__spare__   [4]int32
}

	// See https://github.com/golang/go/issues/30824#issuecomment-492772426
	// This is only correct in the non-cgo case.
	// XXX should use lwp_getprivate as suggested.
	// 8*36 is ucontext.uc_mcontext.__gregs[_REG_X28]
	MOVD	8*36(g), g

	// this might be called in external code context,
	// where g is not set.
	// first save R0, because runtime·load_g will clobber it
	MOVD	R0, 8(RSP)		// signum

type sigcontext struct {
	_unused     [4]uint64
	signal      int32
	_pad0       int32
	handler     uint64
	oldmask     uint64
	regs        *ptregs
	gp_regs     [48]uint64
	fp_regs     [33]float64
	v_regs      *vreg
	vmx_reserve [101]int64
}

type ucontext struct {
	uc_flags    uint64
	uc_link     *ucontext
	uc_stack    stackt
	uc_sigmask  uint64
	__unused    [15]uint64
	uc_mcontext sigcontext