src/runtime/sys_openbsd_riscv64.s - go - Git at Google

 // Copyright 2023 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.
 //
 // System calls and other sys.stuff for riscv64, OpenBSD
 // System calls are implemented in libc/libpthread, this file
 // contains trampolines that convert from Go to C calling convention.
 //

 #include "go_asm.h"
 #include "go_tls.h"
 #include "textflag.h"

 #define CLOCK_REALTIME	$0
 #define	CLOCK_MONOTONIC	$3

 // mstart_stub is the first function executed on a new thread started by pthread_create.
 // It just does some low-level setup and then calls mstart.
 // Note: called with the C calling convention.
 TEXT runtime·mstart_stub(SB),NOSPLIT,$200
 	// X10 points to the m.
 	// We are already on m's g0 stack.

 	// Save callee-save registers (X8, X9, X18..X27, F8, F9, F18..F27)
 	MOV	X8, (1*8)(X2)
 	MOV	X9, (2*8)(X2)
 	MOV	X18, (3*8)(X2)
 	MOV	X19, (4*8)(X2)
 	MOV	X20, (5*8)(X2)
 	MOV	X21, (6*8)(X2)
 	MOV	X22, (7*8)(X2)
 	MOV	X23, (8*8)(X2)
 	MOV	X24, (9*8)(X2)
 	MOV	X25, (10*8)(X2)
 	MOV	X26, (11*8)(X2)
 	MOV	g, (12*8)(X2)
 	MOVF	F8, (13*8)(X2)
 	MOVF	F9, (14*8)(X2)
 	MOVF	F18, (15*8)(X2)
 	MOVF	F19, (16*8)(X2)
 	MOVF	F20, (17*8)(X2)
 	MOVF	F21, (18*8)(X2)
 	MOVF	F22, (19*8)(X2)
 	MOVF	F23, (20*8)(X2)
 	MOVF	F24, (21*8)(X2)
 	MOVF	F25, (22*8)(X2)
 	MOVF	F26, (23*8)(X2)
 	MOVF	F27, (24*8)(X2)

 	MOV	m_g0(X10), g
 	CALL	runtime·save_g(SB)

 	CALL	runtime·mstart(SB)

 	// Restore callee-save registers.
 	MOV	(1*8)(X2), X8
 	MOV	(2*8)(X2), X9
 	MOV	(3*8)(X2), X18
 	MOV	(4*8)(X2), X19
 	MOV	(5*8)(X2), X20
 	MOV	(6*8)(X2), X21
 	MOV	(7*8)(X2), X22
 	MOV	(8*8)(X2), X23
 	MOV	(9*8)(X2), X24
 	MOV	(10*8)(X2), X25
 	MOV	(11*8)(X2), X26
 	MOV	(12*8)(X2), g
 	MOVF	(13*8)(X2), F8
 	MOVF	(14*8)(X2), F9
 	MOVF	(15*8)(X2), F18
 	MOVF	(16*8)(X2), F19
 	MOVF	(17*8)(X2), F20
 	MOVF	(18*8)(X2), F21
 	MOVF	(19*8)(X2), F22
 	MOVF	(20*8)(X2), F23
 	MOVF	(21*8)(X2), F24
 	MOVF	(22*8)(X2), F25
 	MOVF	(23*8)(X2), F26
 	MOVF	(24*8)(X2), F27

 	// Go is all done with this OS thread.
 	// Tell pthread everything is ok (we never join with this thread, so
 	// the value here doesn't really matter).
 	MOV	$0, X10

 	RET

 TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
 	MOVW	sig+8(FP), X10
 	MOV	info+16(FP), X11
 	MOV	ctx+24(FP), X12
 	MOV	fn+0(FP), X5
 	JALR	X1, X5
 	RET

 TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$224
 	// Save callee-save registers (X8, X9, X18..X27, F8, F9, F18..F27)
 	MOV	X8, (4*8)(X2)
 	MOV	X9, (5*8)(X2)
 	MOV	X18, (6*8)(X2)
 	MOV	X19, (7*8)(X2)
 	MOV	X20, (8*8)(X2)
 	MOV	X21, (9*8)(X2)
 	MOV	X22, (10*8)(X2)
 	MOV	X23, (11*8)(X2)
 	MOV	X24, (12*8)(X2)
 	MOV	X25, (13*8)(X2)
 	MOV	X26, (14*8)(X2)
 	MOV	g, (15*8)(X2)
 	MOVF	F8, (16*8)(X2)
 	MOVF	F9, (17*8)(X2)
 	MOVF	F18, (18*8)(X2)
 	MOVF	F19, (19*8)(X2)
 	MOVF	F20, (20*8)(X2)
 	MOVF	F21, (21*8)(X2)
 	MOVF	F22, (22*8)(X2)
 	MOVF	F23, (23*8)(X2)
 	MOVF	F24, (24*8)(X2)
 	MOVF	F25, (25*8)(X2)
 	MOVF	F26, (26*8)(X2)
 	MOVF	F27, (27*8)(X2)

 	// this might be called in external code context,
 	// where g is not set.
 	CALL	runtime·load_g(SB)

 	MOVW	X10, 8(X2)
 	MOV	X11, 16(X2)
 	MOV	X12, 24(X2)
 	MOV	$runtime·sigtrampgo(SB), X5
 	JALR	X1, X5

 	// Restore callee-save registers.
 	MOV	(4*8)(X2), X8
 	MOV	(5*8)(X2), X9
 	MOV	(6*8)(X2), X18
 	MOV	(7*8)(X2), X19
 	MOV	(8*8)(X2), X20
 	MOV	(9*8)(X2), X21
 	MOV	(10*8)(X2), X22
 	MOV	(11*8)(X2), X23
 	MOV	(12*8)(X2), X24
 	MOV	(13*8)(X2), X25
 	MOV	(14*8)(X2), X26
 	MOV	(15*8)(X2), g
 	MOVF	(16*8)(X2), F8
 	MOVF	(17*8)(X2), F9
 	MOVF	(18*8)(X2), F18
 	MOVF	(19*8)(X2), F19
 	MOVF	(20*8)(X2), F20
 	MOVF	(21*8)(X2), F21
 	MOVF	(22*8)(X2), F22
 	MOVF	(23*8)(X2), F23
 	MOVF	(24*8)(X2), F24
 	MOVF	(25*8)(X2), F25
 	MOVF	(26*8)(X2), F26
 	MOVF	(27*8)(X2), F27

 	RET

 //
 // These trampolines help convert from Go calling convention to C calling convention.
 // They should be called with asmcgocall.
 // A pointer to the arguments is passed in R0.
 // A single int32 result is returned in R0.
 // (For more results, make an args/results structure.)
 TEXT runtime·pthread_attr_init_trampoline(SB),NOSPLIT,$8
 	MOV	0(X10), X10		// arg 1 - attr
 	CALL	libc_pthread_attr_init(SB)
 	RET

 TEXT runtime·pthread_attr_destroy_trampoline(SB),NOSPLIT,$8
 	MOV	0(X10), X10		// arg 1 - attr
 	CALL	libc_pthread_attr_destroy(SB)
 	RET

 TEXT runtime·pthread_attr_getstacksize_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - size
 	MOV	0(X10), X10		// arg 1 - attr
 	CALL	libc_pthread_attr_getstacksize(SB)
 	RET

 TEXT runtime·pthread_attr_setdetachstate_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - state
 	MOV	0(X10), X10		// arg 1 - attr
 	CALL	libc_pthread_attr_setdetachstate(SB)
 	RET

 TEXT runtime·pthread_create_trampoline(SB),NOSPLIT,$8
 	MOV	0(X10), X11		// arg 2 - attr
 	MOV	8(X10), X12		// arg 3 - start
 	MOV	16(X10), X13		// arg 4 - arg
 	ADD	$-16, X2
 	MOV	X2, X10			// arg 1 - &threadid (discard)
 	CALL	libc_pthread_create(SB)
 	ADD	$16, X2
 	RET

 TEXT runtime·thrkill_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - signal
 	MOV	$0, X12			// arg 3 - tcb
 	MOVW	0(X10), X10		// arg 1 - tid
 	CALL	libc_thrkill(SB)
 	RET

 TEXT runtime·thrsleep_trampoline(SB),NOSPLIT,$8
 	MOVW	8(X10), X11		// arg 2 - clock_id
 	MOV	16(X10), X12		// arg 3 - abstime
 	MOV	24(X10), X13		// arg 4 - lock
 	MOV	32(X10), X14		// arg 5 - abort
 	MOV	0(X10), X10		// arg 1 - id
 	CALL	libc_thrsleep(SB)
 	RET

 TEXT runtime·thrwakeup_trampoline(SB),NOSPLIT,$8
 	MOVW	8(X10), X11		// arg 2 - count
 	MOV	0(X10), X10		// arg 1 - id
 	CALL	libc_thrwakeup(SB)
 	RET

 TEXT runtime·exit_trampoline(SB),NOSPLIT,$8
 	MOVW	0(X10), X10		// arg 1 - status
 	CALL	libc_exit(SB)
 	MOV	$0, X5			// crash on failure
 	MOV	X5, (X5)
 	RET

 TEXT runtime·getthrid_trampoline(SB),NOSPLIT,$8
 	MOV	X10, X9			// pointer to args
 	CALL	libc_getthrid(SB)
 	MOVW	X10, 0(X9)		// return value
 	RET

 TEXT runtime·raiseproc_trampoline(SB),NOSPLIT,$8
 	MOV	X10, X9			// pointer to args
 	CALL	libc_getpid(SB)		// arg 1 - pid (result in X10)
 	MOVW	0(X9), X11		// arg 2 - signal
 	CALL	libc_kill(SB)
 	RET

 TEXT runtime·sched_yield_trampoline(SB),NOSPLIT,$8
 	CALL	libc_sched_yield(SB)
 	RET

 TEXT runtime·mmap_trampoline(SB),NOSPLIT,$8
 	MOV	X10, X9			// pointer to args
 	MOV	0(X9), X10		// arg 1 - addr
 	MOV	8(X9), X11		// arg 2 - len
 	MOVW	16(X9), X12		// arg 3 - prot
 	MOVW	20(X9), X13		// arg 4 - flags
 	MOVW	24(X9), X14		// arg 5 - fid
 	MOVW	28(X9), X15		// arg 6 - offset
 	CALL	libc_mmap(SB)
 	MOV	$0, X5
 	MOV	$-1, X6
 	BNE	X6, X10, noerr
 	CALL	libc_errno(SB)
 	MOVW	(X10), X5		// errno
 	MOV	$0, X10
 noerr:
 	MOV	X10, 32(X9)
 	MOV	X5, 40(X9)
 	RET

 TEXT runtime·munmap_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - len
 	MOV	0(X10), X10		// arg 1 - addr
 	CALL	libc_munmap(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, 3(PC)
 	MOV	$0, X5			// crash on failure
 	MOV	X5, (X5)
 	RET

 TEXT runtime·madvise_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - len
 	MOVW	16(X10), X12		// arg 3 - advice
 	MOV	0(X10), X10		// arg 1 - addr
 	CALL	libc_madvise(SB)
 	// ignore failure - maybe pages are locked
 	RET

 TEXT runtime·open_trampoline(SB),NOSPLIT,$8
 	MOVW	8(X10), X11		// arg 2 - flags
 	MOVW	12(X10), X12		// arg 3 - mode
 	MOV	0(X10), X10		// arg 1 - path
 	MOV	$0, X13			// varargs
 	CALL	libc_open(SB)
 	RET

 TEXT runtime·close_trampoline(SB),NOSPLIT,$8
 	MOVW	0(X10), X10		// arg 1 - fd
 	CALL	libc_close(SB)
 	RET

 TEXT runtime·read_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - buf
 	MOVW	16(X10), X12		// arg 3 - count
 	MOVW	0(X10), X10		// arg 1 - fd (int32 from read)
 	CALL	libc_read(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, noerr
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10		// errno
 	NEG	X10			// caller expects negative errno
 noerr:
 	RET

 TEXT runtime·write_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - buf
 	MOVW	16(X10), X12		// arg 3 - count
 	MOV	0(X10), X10		// arg 1 - fd (uintptr from write1)
 	CALL	libc_write(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, noerr
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10		// errno
 	NEG	X10			// caller expects negative errno
 noerr:
 	RET

 TEXT runtime·pipe2_trampoline(SB),NOSPLIT,$8
 	MOVW	8(X10), X11		// arg 2 - flags
 	MOV	0(X10), X10		// arg 1 - filedes
 	CALL	libc_pipe2(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, noerr
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10		// errno
 	NEG	X10			// caller expects negative errno
 noerr:
 	RET

 TEXT runtime·setitimer_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - new
 	MOV	16(X10), X12		// arg 3 - old
 	MOVW	0(X10), X10		// arg 1 - which
 	CALL	libc_setitimer(SB)
 	RET

 TEXT runtime·usleep_trampoline(SB),NOSPLIT,$8
 	MOVW	0(X10), X10		// arg 1 - usec
 	CALL	libc_usleep(SB)
 	RET

 TEXT runtime·sysctl_trampoline(SB),NOSPLIT,$8
 	MOVW	8(X10), X11		// arg 2 - miblen
 	MOV	16(X10), X12		// arg 3 - out
 	MOV	24(X10), X13		// arg 4 - size
 	MOV	32(X10), X14		// arg 5 - dst
 	MOV	40(X10), X15		// arg 6 - ndst
 	MOV	0(X10), X10		// arg 1 - mib
 	CALL	libc_sysctl(SB)
 	RET

 TEXT runtime·kqueue_trampoline(SB),NOSPLIT,$8
 	CALL	libc_kqueue(SB)
 	RET

 TEXT runtime·kevent_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - keventt
 	MOVW	16(X10), X12		// arg 3 - nch
 	MOV	24(X10), X13		// arg 4 - ev
 	MOVW	32(X10), X14		// arg 5 - nev
 	MOV	40(X10), X15		// arg 6 - ts
 	MOVW	0(X10), X10		// arg 1 - kq
 	CALL	libc_kevent(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, noerr
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10		// errno
 	NEG	X10			// caller expects negative errno
 noerr:
 	RET

 TEXT runtime·clock_gettime_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - tp
 	MOVW	0(X10), X10		// arg 1 - clock_id
 	CALL	libc_clock_gettime(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, 3(PC)
 	MOV	$0, X5			// crash on failure
 	MOV	X5, (X5)
 	RET

 TEXT runtime·fcntl_trampoline(SB),NOSPLIT,$8
 	MOV	X10, X9			// pointer to args
 	MOVW	0(X9), X10		// arg 1 - fd
 	MOVW	4(X9), X11		// arg 2 - cmd
 	MOVW	8(X9), X12		// arg 3 - arg
 	MOV	$0, X13			// vararg
 	CALL	libc_fcntl(SB)
 	MOV	$-1, X5
 	MOV	$0, X11
 	BNE	X5, X10, noerr
 	CALL	libc_errno(SB)
 	MOVW	(X10), X11		// errno
 	MOV	$-1, X10
 noerr:
 	MOVW	X10, 12(X9)
 	MOVW	X11, 16(X9)
 	RET

 TEXT runtime·sigaction_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - new
 	MOV	16(X10), X12		// arg 3 - old
 	MOVW	0(X10), X10		// arg 1 - sig
 	CALL	libc_sigaction(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, 3(PC)
 	MOV	$0, X5			// crash on failure
 	MOV	X5, (X5)
 	RET

 TEXT runtime·sigprocmask_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - new
 	MOV	16(X10), X12		// arg 3 - old
 	MOVW	0(X10), X10		// arg 1 - how
 	CALL	libc_pthread_sigmask(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, 3(PC)
 	MOV	$0, X5			// crash on failure
 	MOV	X5, (X5)
 	RET

 TEXT runtime·sigaltstack_trampoline(SB),NOSPLIT,$8
 	MOV	8(X10), X11		// arg 2 - old
 	MOV	0(X10), X10		// arg 1 - new
 	CALL	libc_sigaltstack(SB)
 	MOV	$-1, X5
 	BNE	X5, X10, 3(PC)
 	MOV	$0, X5			// crash on failure
 	MOV	X5, (X5)
 	RET

 TEXT runtime·issetugid_trampoline(SB),NOSPLIT,$0
 	MOV	X10, X9			// pointer to args
 	CALL	libc_issetugid(SB)
 	MOVW	X10, 0(X9)		// return value
 	RET

 // syscall calls a function in libc on behalf of the syscall package.
 // syscall takes a pointer to a struct like:
 // struct {
 //	fn    uintptr
 //	a1    uintptr
 //	a2    uintptr
 //	a3    uintptr
 //	r1    uintptr
 //	r2    uintptr
 //	err   uintptr
 // }
 // syscall must be called on the g0 stack with the
 // C calling convention (use libcCall).
 //
 // syscall expects a 32-bit result and tests for 32-bit -1
 // to decide there was an error.
 TEXT runtime·syscall(SB),NOSPLIT,$8
 	MOV	X10, X9			// pointer to args

 	MOV	(0*8)(X9), X5		// fn
 	MOV	(1*8)(X9), X10		// a1
 	MOV	(2*8)(X9), X11		// a2
 	MOV	(3*8)(X9), X12		// a3
 	MOV	$0, X13			// vararg

 	JALR	X1, X5

 	MOV	X10, (4*8)(X9)		// r1
 	MOV	X11, (5*8)(X9)		// r2

 	// Standard libc functions return -1 on error
 	// and set errno.
 	MOV	$-1, X5
 	MOVW	X10, X11
 	BNE	X5, X11, ok

 	// Get error code from libc.
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10
 	MOV	X10, (6*8)(X9)		// err

 ok:
 	RET

 // syscallX calls a function in libc on behalf of the syscall package.
 // syscallX takes a pointer to a struct like:
 // struct {
 //	fn    uintptr
 //	a1    uintptr
 //	a2    uintptr
 //	a3    uintptr
 //	r1    uintptr
 //	r2    uintptr
 //	err   uintptr
 // }
 // syscallX must be called on the g0 stack with the
 // C calling convention (use libcCall).
 //
 // syscallX is like syscall but expects a 64-bit result
 // and tests for 64-bit -1 to decide there was an error.
 TEXT runtime·syscallX(SB),NOSPLIT,$8
 	MOV	X10, X9			// pointer to args

 	MOV	(0*8)(X9), X5		// fn
 	MOV	(1*8)(X9), X10		// a1
 	MOV	(2*8)(X9), X11		// a2
 	MOV	(3*8)(X9), X12		// a3
 	MOV	$0, X13			// vararg

 	JALR	X1, X5

 	MOV	X10, (4*8)(X9)		// r1
 	MOV	X11, (5*8)(X9)		// r2

 	// Standard libc functions return -1 on error
 	// and set errno.
 	MOV	$-1, X5
 	BNE	X5, X10, ok

 	// Get error code from libc.
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10
 	MOV	X10, (6*8)(X9)		// err

 ok:
 	RET

 // syscall6 calls a function in libc on behalf of the syscall package.
 // syscall6 takes a pointer to a struct like:
 // struct {
 //	fn    uintptr
 //	a1    uintptr
 //	a2    uintptr
 //	a3    uintptr
 //	a4    uintptr
 //	a5    uintptr
 //	a6    uintptr
 //	r1    uintptr
 //	r2    uintptr
 //	err   uintptr
 // }
 // syscall6 must be called on the g0 stack with the
 // C calling convention (use libcCall).
 //
 // syscall6 expects a 32-bit result and tests for 32-bit -1
 // to decide there was an error.
 TEXT runtime·syscall6(SB),NOSPLIT,$8
 	MOV	X10, X9			// pointer to args

 	MOV	(0*8)(X9), X5		// fn
 	MOV	(1*8)(X9), X10		// a1
 	MOV	(2*8)(X9), X11		// a2
 	MOV	(3*8)(X9), X12		// a3
 	MOV	(4*8)(X9), X13		// a4
 	MOV	(5*8)(X9), X14		// a5
 	MOV	(6*8)(X9), X15		// a6
 	MOV	$0, X16			// vararg

 	JALR	X1, X5

 	MOV	X10, (7*8)(X9)		// r1
 	MOV	X11, (8*8)(X9)		// r2

 	// Standard libc functions return -1 on error
 	// and set errno.
 	MOV	$-1, X5
 	MOVW	X10, X11
 	BNE	X5, X11, ok

 	// Get error code from libc.
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10
 	MOV	X10, (9*8)(X9)		// err

 ok:
 	RET

 // syscall6X calls a function in libc on behalf of the syscall package.
 // syscall6X takes a pointer to a struct like:
 // struct {
 //	fn    uintptr
 //	a1    uintptr
 //	a2    uintptr
 //	a3    uintptr
 //	a4    uintptr
 //	a5    uintptr
 //	a6    uintptr
 //	r1    uintptr
 //	r2    uintptr
 //	err   uintptr
 // }
 // syscall6X must be called on the g0 stack with the
 // C calling convention (use libcCall).
 //
 // syscall6X is like syscall6 but expects a 64-bit result
 // and tests for 64-bit -1 to decide there was an error.
 TEXT runtime·syscall6X(SB),NOSPLIT,$8
 	MOV	X10, X9			// pointer to args

 	MOV	(0*8)(X9), X5		// fn
 	MOV	(1*8)(X9), X10		// a1
 	MOV	(2*8)(X9), X11		// a2
 	MOV	(3*8)(X9), X12		// a3
 	MOV	(4*8)(X9), X13		// a4
 	MOV	(5*8)(X9), X14		// a5
 	MOV	(6*8)(X9), X15		// a6
 	MOV	$0, X16			// vararg

 	JALR	X1, X5

 	MOV	X10, (7*8)(X9)		// r1
 	MOV	X11, (8*8)(X9)		// r2

 	// Standard libc functions return -1 on error
 	// and set errno.
 	MOV	$-1, X5
 	BNE	X5, X10, ok

 	// Get error code from libc.
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10
 	MOV	X10, (9*8)(X9)		// err

 ok:
 	RET

 // syscall10 calls a function in libc on behalf of the syscall package.
 // syscall10 takes a pointer to a struct like:
 // struct {
 //	fn    uintptr
 //	a1    uintptr
 //	a2    uintptr
 //	a3    uintptr
 //	a4    uintptr
 //	a5    uintptr
 //	a6    uintptr
 //	a7    uintptr
 //	a8    uintptr
 //	a9    uintptr
 //	a10   uintptr
 //	r1    uintptr
 //	r2    uintptr
 //	err   uintptr
 // }
 // syscall10 must be called on the g0 stack with the
 // C calling convention (use libcCall).
 //
 // The openbsd/riscv64 kernel only accepts eight syscall arguments.
 TEXT runtime·syscall10(SB),NOSPLIT,$0
 	MOV	X10, X9			// pointer to args

 	ADD	$-16, X2

 	MOV	(0*8)(X9), X5		// fn
 	MOV	(1*8)(X9), X10		// a1
 	MOV	(2*8)(X9), X11		// a2
 	MOV	(3*8)(X9), X12		// a3
 	MOV	(4*8)(X9), X13		// a4
 	MOV	(5*8)(X9), X14		// a5
 	MOV	(6*8)(X9), X15		// a6
 	MOV	(7*8)(X9), X16		// a7
 	MOV	(8*8)(X9), X17		// a8

 	JALR	X1, X5

 	MOV	X10, (11*8)(X9)		// r1
 	MOV	X11, (12*8)(X9)		// r2

 	// Standard libc functions return -1 on error
 	// and set errno.
 	MOV	$-1, X5
 	MOVW	X10, X11
 	BNE	X5, X11, ok

 	// Get error code from libc.
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10
 	MOV	X10, (13*8)(X9)		// err

 ok:
 	ADD	$16, X2
 	RET

 // syscall10X calls a function in libc on behalf of the syscall package.
 // syscall10X takes a pointer to a struct like:
 // struct {
 //	fn    uintptr
 //	a1    uintptr
 //	a2    uintptr
 //	a3    uintptr
 //	a4    uintptr
 //	a5    uintptr
 //	a6    uintptr
 //	a7    uintptr
 //	a8    uintptr
 //	a9    uintptr
 //	a10   uintptr
 //	r1    uintptr
 //	r2    uintptr
 //	err   uintptr
 // }
 // syscall10X must be called on the g0 stack with the
 // C calling convention (use libcCall).
 //
 // syscall10X is like syscall10 but expects a 64-bit result
 // and tests for 64-bit -1 to decide there was an error.
 //
 // The openbsd/riscv64 kernel only accepts eight syscall arguments.
 TEXT runtime·syscall10X(SB),NOSPLIT,$0
 	MOV	X10, X9			// pointer to args

 	ADD	$-16, X2

 	MOV	(0*8)(X9), X5		// fn
 	MOV	(1*8)(X9), X10		// a1
 	MOV	(2*8)(X9), X11		// a2
 	MOV	(3*8)(X9), X12		// a3
 	MOV	(4*8)(X9), X13		// a4
 	MOV	(5*8)(X9), X14		// a5
 	MOV	(6*8)(X9), X15		// a6
 	MOV	(7*8)(X9), X16		// a7
 	MOV	(8*8)(X9), X17		// a8

 	JALR	X1, X5

 	MOV	X10, (11*8)(X9)		// r1
 	MOV	X11, (12*8)(X9)		// r2

 	// Standard libc functions return -1 on error
 	// and set errno.
 	MOV	$-1, X5
 	BNE	X5, X10, ok

 	// Get error code from libc.
 	CALL	libc_errno(SB)
 	MOVW	(X10), X10
 	MOV	X10, (13*8)(X9)		// err

 ok:
 	ADD	$16, X2
 	RET
	// Copyright 2023 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.
	//
	// System calls and other sys.stuff for riscv64, OpenBSD
	// System calls are implemented in libc/libpthread, this file
	// contains trampolines that convert from Go to C calling convention.
	//

	#include "go_asm.h"
	#include "go_tls.h"
	#include "textflag.h"

	#define CLOCK_REALTIME $0
	#define CLOCK_MONOTONIC $3

	// mstart_stub is the first function executed on a new thread started by pthread_create.
	// It just does some low-level setup and then calls mstart.
	// Note: called with the C calling convention.
	TEXT runtime·mstart_stub(SB),NOSPLIT,$200
	// X10 points to the m.
	// We are already on m's g0 stack.

	// Save callee-save registers (X8, X9, X18..X27, F8, F9, F18..F27)
	MOV X8, (1*8)(X2)
	MOV X9, (2*8)(X2)
	MOV X18, (3*8)(X2)
	MOV X19, (4*8)(X2)
	MOV X20, (5*8)(X2)
	MOV X21, (6*8)(X2)
	MOV X22, (7*8)(X2)
	MOV X23, (8*8)(X2)
	MOV X24, (9*8)(X2)
	MOV X25, (10*8)(X2)
	MOV X26, (11*8)(X2)
	MOV g, (12*8)(X2)
	MOVF F8, (13*8)(X2)
	MOVF F9, (14*8)(X2)
	MOVF F18, (15*8)(X2)
	MOVF F19, (16*8)(X2)
	MOVF F20, (17*8)(X2)
	MOVF F21, (18*8)(X2)
	MOVF F22, (19*8)(X2)
	MOVF F23, (20*8)(X2)
	MOVF F24, (21*8)(X2)
	MOVF F25, (22*8)(X2)
	MOVF F26, (23*8)(X2)
	MOVF F27, (24*8)(X2)

	MOV m_g0(X10), g
	CALL runtime·save_g(SB)

	CALL runtime·mstart(SB)

	// Restore callee-save registers.
	MOV (1*8)(X2), X8
	MOV (2*8)(X2), X9
	MOV (3*8)(X2), X18
	MOV (4*8)(X2), X19
	MOV (5*8)(X2), X20
	MOV (6*8)(X2), X21
	MOV (7*8)(X2), X22
	MOV (8*8)(X2), X23
	MOV (9*8)(X2), X24
	MOV (10*8)(X2), X25
	MOV (11*8)(X2), X26
	MOV (12*8)(X2), g
	MOVF (13*8)(X2), F8
	MOVF (14*8)(X2), F9
	MOVF (15*8)(X2), F18
	MOVF (16*8)(X2), F19
	MOVF (17*8)(X2), F20
	MOVF (18*8)(X2), F21
	MOVF (19*8)(X2), F22
	MOVF (20*8)(X2), F23
	MOVF (21*8)(X2), F24
	MOVF (22*8)(X2), F25
	MOVF (23*8)(X2), F26
	MOVF (24*8)(X2), F27

	// Go is all done with this OS thread.
	// Tell pthread everything is ok (we never join with this thread, so
	// the value here doesn't really matter).
	MOV $0, X10

	RET

	TEXT runtime·sigfwd(SB),NOSPLIT,$0-32
	MOVW sig+8(FP), X10
	MOV info+16(FP), X11
	MOV ctx+24(FP), X12
	MOV fn+0(FP), X5
	JALR X1, X5
	RET

	TEXT runtime·sigtramp(SB),NOSPLIT\|TOPFRAME,$224
	// Save callee-save registers (X8, X9, X18..X27, F8, F9, F18..F27)
	MOV X8, (4*8)(X2)
	MOV X9, (5*8)(X2)
	MOV X18, (6*8)(X2)
	MOV X19, (7*8)(X2)
	MOV X20, (8*8)(X2)
	MOV X21, (9*8)(X2)
	MOV X22, (10*8)(X2)
	MOV X23, (11*8)(X2)
	MOV X24, (12*8)(X2)
	MOV X25, (13*8)(X2)
	MOV X26, (14*8)(X2)
	MOV g, (15*8)(X2)
	MOVF F8, (16*8)(X2)
	MOVF F9, (17*8)(X2)
	MOVF F18, (18*8)(X2)
	MOVF F19, (19*8)(X2)
	MOVF F20, (20*8)(X2)
	MOVF F21, (21*8)(X2)
	MOVF F22, (22*8)(X2)
	MOVF F23, (23*8)(X2)
	MOVF F24, (24*8)(X2)
	MOVF F25, (25*8)(X2)
	MOVF F26, (26*8)(X2)
	MOVF F27, (27*8)(X2)

	// this might be called in external code context,
	// where g is not set.
	CALL runtime·load_g(SB)

	MOVW X10, 8(X2)
	MOV X11, 16(X2)
	MOV X12, 24(X2)
	MOV $runtime·sigtrampgo(SB), X5
	JALR X1, X5

	// Restore callee-save registers.
	MOV (4*8)(X2), X8
	MOV (5*8)(X2), X9
	MOV (6*8)(X2), X18
	MOV (7*8)(X2), X19
	MOV (8*8)(X2), X20
	MOV (9*8)(X2), X21
	MOV (10*8)(X2), X22
	MOV (11*8)(X2), X23
	MOV (12*8)(X2), X24
	MOV (13*8)(X2), X25
	MOV (14*8)(X2), X26
	MOV (15*8)(X2), g
	MOVF (16*8)(X2), F8
	MOVF (17*8)(X2), F9
	MOVF (18*8)(X2), F18
	MOVF (19*8)(X2), F19
	MOVF (20*8)(X2), F20
	MOVF (21*8)(X2), F21
	MOVF (22*8)(X2), F22
	MOVF (23*8)(X2), F23
	MOVF (24*8)(X2), F24
	MOVF (25*8)(X2), F25
	MOVF (26*8)(X2), F26
	MOVF (27*8)(X2), F27

	RET

	//
	// These trampolines help convert from Go calling convention to C calling convention.
	// They should be called with asmcgocall.
	// A pointer to the arguments is passed in R0.
	// A single int32 result is returned in R0.
	// (For more results, make an args/results structure.)
	TEXT runtime·pthread_attr_init_trampoline(SB),NOSPLIT,$8
	MOV 0(X10), X10 // arg 1 - attr
	CALL libc_pthread_attr_init(SB)
	RET

	TEXT runtime·pthread_attr_destroy_trampoline(SB),NOSPLIT,$8
	MOV 0(X10), X10 // arg 1 - attr
	CALL libc_pthread_attr_destroy(SB)
	RET

	TEXT runtime·pthread_attr_getstacksize_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - size
	MOV 0(X10), X10 // arg 1 - attr
	CALL libc_pthread_attr_getstacksize(SB)
	RET

	TEXT runtime·pthread_attr_setdetachstate_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - state
	MOV 0(X10), X10 // arg 1 - attr
	CALL libc_pthread_attr_setdetachstate(SB)
	RET

	TEXT runtime·pthread_create_trampoline(SB),NOSPLIT,$8
	MOV 0(X10), X11 // arg 2 - attr
	MOV 8(X10), X12 // arg 3 - start
	MOV 16(X10), X13 // arg 4 - arg
	ADD $-16, X2
	MOV X2, X10 // arg 1 - &threadid (discard)
	CALL libc_pthread_create(SB)
	ADD $16, X2
	RET

	TEXT runtime·thrkill_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - signal
	MOV $0, X12 // arg 3 - tcb
	MOVW 0(X10), X10 // arg 1 - tid
	CALL libc_thrkill(SB)
	RET

	TEXT runtime·thrsleep_trampoline(SB),NOSPLIT,$8
	MOVW 8(X10), X11 // arg 2 - clock_id
	MOV 16(X10), X12 // arg 3 - abstime
	MOV 24(X10), X13 // arg 4 - lock
	MOV 32(X10), X14 // arg 5 - abort
	MOV 0(X10), X10 // arg 1 - id
	CALL libc_thrsleep(SB)
	RET

	TEXT runtime·thrwakeup_trampoline(SB),NOSPLIT,$8
	MOVW 8(X10), X11 // arg 2 - count
	MOV 0(X10), X10 // arg 1 - id
	CALL libc_thrwakeup(SB)
	RET

	TEXT runtime·exit_trampoline(SB),NOSPLIT,$8
	MOVW 0(X10), X10 // arg 1 - status
	CALL libc_exit(SB)
	MOV $0, X5 // crash on failure
	MOV X5, (X5)
	RET

	TEXT runtime·getthrid_trampoline(SB),NOSPLIT,$8
	MOV X10, X9 // pointer to args
	CALL libc_getthrid(SB)
	MOVW X10, 0(X9) // return value
	RET

	TEXT runtime·raiseproc_trampoline(SB),NOSPLIT,$8
	MOV X10, X9 // pointer to args
	CALL libc_getpid(SB) // arg 1 - pid (result in X10)
	MOVW 0(X9), X11 // arg 2 - signal
	CALL libc_kill(SB)
	RET

	TEXT runtime·sched_yield_trampoline(SB),NOSPLIT,$8
	CALL libc_sched_yield(SB)
	RET

	TEXT runtime·mmap_trampoline(SB),NOSPLIT,$8
	MOV X10, X9 // pointer to args
	MOV 0(X9), X10 // arg 1 - addr
	MOV 8(X9), X11 // arg 2 - len
	MOVW 16(X9), X12 // arg 3 - prot
	MOVW 20(X9), X13 // arg 4 - flags
	MOVW 24(X9), X14 // arg 5 - fid
	MOVW 28(X9), X15 // arg 6 - offset
	CALL libc_mmap(SB)
	MOV $0, X5
	MOV $-1, X6
	BNE X6, X10, noerr
	CALL libc_errno(SB)
	MOVW (X10), X5 // errno
	MOV $0, X10
	noerr:
	MOV X10, 32(X9)
	MOV X5, 40(X9)
	RET

	TEXT runtime·munmap_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - len
	MOV 0(X10), X10 // arg 1 - addr
	CALL libc_munmap(SB)
	MOV $-1, X5
	BNE X5, X10, 3(PC)
	MOV $0, X5 // crash on failure
	MOV X5, (X5)
	RET

	TEXT runtime·madvise_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - len
	MOVW 16(X10), X12 // arg 3 - advice
	MOV 0(X10), X10 // arg 1 - addr
	CALL libc_madvise(SB)
	// ignore failure - maybe pages are locked
	RET

	TEXT runtime·open_trampoline(SB),NOSPLIT,$8
	MOVW 8(X10), X11 // arg 2 - flags
	MOVW 12(X10), X12 // arg 3 - mode
	MOV 0(X10), X10 // arg 1 - path
	MOV $0, X13 // varargs
	CALL libc_open(SB)
	RET

	TEXT runtime·close_trampoline(SB),NOSPLIT,$8
	MOVW 0(X10), X10 // arg 1 - fd
	CALL libc_close(SB)
	RET

	TEXT runtime·read_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - buf
	MOVW 16(X10), X12 // arg 3 - count
	MOVW 0(X10), X10 // arg 1 - fd (int32 from read)
	CALL libc_read(SB)
	MOV $-1, X5
	BNE X5, X10, noerr
	CALL libc_errno(SB)
	MOVW (X10), X10 // errno
	NEG X10 // caller expects negative errno
	noerr:
	RET

	TEXT runtime·write_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - buf
	MOVW 16(X10), X12 // arg 3 - count
	MOV 0(X10), X10 // arg 1 - fd (uintptr from write1)
	CALL libc_write(SB)
	MOV $-1, X5
	BNE X5, X10, noerr
	CALL libc_errno(SB)
	MOVW (X10), X10 // errno
	NEG X10 // caller expects negative errno
	noerr:
	RET

	TEXT runtime·pipe2_trampoline(SB),NOSPLIT,$8
	MOVW 8(X10), X11 // arg 2 - flags
	MOV 0(X10), X10 // arg 1 - filedes
	CALL libc_pipe2(SB)
	MOV $-1, X5
	BNE X5, X10, noerr
	CALL libc_errno(SB)
	MOVW (X10), X10 // errno
	NEG X10 // caller expects negative errno
	noerr:
	RET

	TEXT runtime·setitimer_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - new
	MOV 16(X10), X12 // arg 3 - old
	MOVW 0(X10), X10 // arg 1 - which
	CALL libc_setitimer(SB)
	RET

	TEXT runtime·usleep_trampoline(SB),NOSPLIT,$8
	MOVW 0(X10), X10 // arg 1 - usec
	CALL libc_usleep(SB)
	RET

	TEXT runtime·sysctl_trampoline(SB),NOSPLIT,$8
	MOVW 8(X10), X11 // arg 2 - miblen
	MOV 16(X10), X12 // arg 3 - out
	MOV 24(X10), X13 // arg 4 - size
	MOV 32(X10), X14 // arg 5 - dst
	MOV 40(X10), X15 // arg 6 - ndst
	MOV 0(X10), X10 // arg 1 - mib
	CALL libc_sysctl(SB)
	RET

	TEXT runtime·kqueue_trampoline(SB),NOSPLIT,$8
	CALL libc_kqueue(SB)
	RET

	TEXT runtime·kevent_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - keventt
	MOVW 16(X10), X12 // arg 3 - nch
	MOV 24(X10), X13 // arg 4 - ev
	MOVW 32(X10), X14 // arg 5 - nev
	MOV 40(X10), X15 // arg 6 - ts
	MOVW 0(X10), X10 // arg 1 - kq
	CALL libc_kevent(SB)
	MOV $-1, X5
	BNE X5, X10, noerr
	CALL libc_errno(SB)
	MOVW (X10), X10 // errno
	NEG X10 // caller expects negative errno
	noerr:
	RET

	TEXT runtime·clock_gettime_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - tp
	MOVW 0(X10), X10 // arg 1 - clock_id
	CALL libc_clock_gettime(SB)
	MOV $-1, X5
	BNE X5, X10, 3(PC)
	MOV $0, X5 // crash on failure
	MOV X5, (X5)
	RET

	TEXT runtime·fcntl_trampoline(SB),NOSPLIT,$8
	MOV X10, X9 // pointer to args
	MOVW 0(X9), X10 // arg 1 - fd
	MOVW 4(X9), X11 // arg 2 - cmd
	MOVW 8(X9), X12 // arg 3 - arg
	MOV $0, X13 // vararg
	CALL libc_fcntl(SB)
	MOV $-1, X5
	MOV $0, X11
	BNE X5, X10, noerr
	CALL libc_errno(SB)
	MOVW (X10), X11 // errno
	MOV $-1, X10
	noerr:
	MOVW X10, 12(X9)
	MOVW X11, 16(X9)
	RET

	TEXT runtime·sigaction_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - new
	MOV 16(X10), X12 // arg 3 - old
	MOVW 0(X10), X10 // arg 1 - sig
	CALL libc_sigaction(SB)
	MOV $-1, X5
	BNE X5, X10, 3(PC)
	MOV $0, X5 // crash on failure
	MOV X5, (X5)
	RET

	TEXT runtime·sigprocmask_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - new
	MOV 16(X10), X12 // arg 3 - old
	MOVW 0(X10), X10 // arg 1 - how
	CALL libc_pthread_sigmask(SB)
	MOV $-1, X5
	BNE X5, X10, 3(PC)
	MOV $0, X5 // crash on failure
	MOV X5, (X5)
	RET

	TEXT runtime·sigaltstack_trampoline(SB),NOSPLIT,$8
	MOV 8(X10), X11 // arg 2 - old
	MOV 0(X10), X10 // arg 1 - new
	CALL libc_sigaltstack(SB)
	MOV $-1, X5
	BNE X5, X10, 3(PC)
	MOV $0, X5 // crash on failure
	MOV X5, (X5)
	RET

	TEXT runtime·issetugid_trampoline(SB),NOSPLIT,$0
	MOV X10, X9 // pointer to args
	CALL libc_issetugid(SB)
	MOVW X10, 0(X9) // return value
	RET

	// syscall calls a function in libc on behalf of the syscall package.
	// syscall takes a pointer to a struct like:
	// struct {
	// fn uintptr
	// a1 uintptr
	// a2 uintptr
	// a3 uintptr
	// r1 uintptr
	// r2 uintptr
	// err uintptr
	// }
	// syscall must be called on the g0 stack with the
	// C calling convention (use libcCall).
	//
	// syscall expects a 32-bit result and tests for 32-bit -1
	// to decide there was an error.
	TEXT runtime·syscall(SB),NOSPLIT,$8
	MOV X10, X9 // pointer to args

	MOV (0*8)(X9), X5 // fn
	MOV (1*8)(X9), X10 // a1
	MOV (2*8)(X9), X11 // a2
	MOV (3*8)(X9), X12 // a3
	MOV $0, X13 // vararg

	JALR X1, X5

	MOV X10, (4*8)(X9) // r1
	MOV X11, (5*8)(X9) // r2

	// Standard libc functions return -1 on error
	// and set errno.
	MOV $-1, X5
	MOVW X10, X11
	BNE X5, X11, ok

	// Get error code from libc.
	CALL libc_errno(SB)
	MOVW (X10), X10
	MOV X10, (6*8)(X9) // err

	ok:
	RET

	// syscallX calls a function in libc on behalf of the syscall package.
	// syscallX takes a pointer to a struct like:
	// struct {
	// fn uintptr
	// a1 uintptr
	// a2 uintptr
	// a3 uintptr
	// r1 uintptr
	// r2 uintptr
	// err uintptr
	// }
	// syscallX must be called on the g0 stack with the
	// C calling convention (use libcCall).
	//
	// syscallX is like syscall but expects a 64-bit result
	// and tests for 64-bit -1 to decide there was an error.
	TEXT runtime·syscallX(SB),NOSPLIT,$8
	MOV X10, X9 // pointer to args

	MOV (0*8)(X9), X5 // fn
	MOV (1*8)(X9), X10 // a1
	MOV (2*8)(X9), X11 // a2
	MOV (3*8)(X9), X12 // a3
	MOV $0, X13 // vararg

	JALR X1, X5

	MOV X10, (4*8)(X9) // r1
	MOV X11, (5*8)(X9) // r2

	// Standard libc functions return -1 on error
	// and set errno.
	MOV $-1, X5
	BNE X5, X10, ok

	// Get error code from libc.
	CALL libc_errno(SB)
	MOVW (X10), X10
	MOV X10, (6*8)(X9) // err

	ok:
	RET

	// syscall6 calls a function in libc on behalf of the syscall package.
	// syscall6 takes a pointer to a struct like:
	// struct {
	// fn uintptr
	// a1 uintptr
	// a2 uintptr
	// a3 uintptr
	// a4 uintptr
	// a5 uintptr
	// a6 uintptr
	// r1 uintptr
	// r2 uintptr
	// err uintptr
	// }
	// syscall6 must be called on the g0 stack with the
	// C calling convention (use libcCall).
	//
	// syscall6 expects a 32-bit result and tests for 32-bit -1
	// to decide there was an error.
	TEXT runtime·syscall6(SB),NOSPLIT,$8
	MOV X10, X9 // pointer to args

	MOV (0*8)(X9), X5 // fn
	MOV (1*8)(X9), X10 // a1
	MOV (2*8)(X9), X11 // a2
	MOV (3*8)(X9), X12 // a3
	MOV (4*8)(X9), X13 // a4
	MOV (5*8)(X9), X14 // a5
	MOV (6*8)(X9), X15 // a6
	MOV $0, X16 // vararg

	JALR X1, X5

	MOV X10, (7*8)(X9) // r1
	MOV X11, (8*8)(X9) // r2

	// Standard libc functions return -1 on error
	// and set errno.
	MOV $-1, X5
	MOVW X10, X11
	BNE X5, X11, ok

	// Get error code from libc.
	CALL libc_errno(SB)
	MOVW (X10), X10
	MOV X10, (9*8)(X9) // err

	ok:
	RET

	// syscall6X calls a function in libc on behalf of the syscall package.
	// syscall6X takes a pointer to a struct like:
	// struct {
	// fn uintptr
	// a1 uintptr
	// a2 uintptr
	// a3 uintptr
	// a4 uintptr
	// a5 uintptr
	// a6 uintptr
	// r1 uintptr
	// r2 uintptr
	// err uintptr
	// }
	// syscall6X must be called on the g0 stack with the
	// C calling convention (use libcCall).
	//
	// syscall6X is like syscall6 but expects a 64-bit result
	// and tests for 64-bit -1 to decide there was an error.
	TEXT runtime·syscall6X(SB),NOSPLIT,$8
	MOV X10, X9 // pointer to args

	MOV (0*8)(X9), X5 // fn
	MOV (1*8)(X9), X10 // a1
	MOV (2*8)(X9), X11 // a2
	MOV (3*8)(X9), X12 // a3
	MOV (4*8)(X9), X13 // a4
	MOV (5*8)(X9), X14 // a5
	MOV (6*8)(X9), X15 // a6
	MOV $0, X16 // vararg

	JALR X1, X5

	MOV X10, (7*8)(X9) // r1
	MOV X11, (8*8)(X9) // r2

	// Standard libc functions return -1 on error
	// and set errno.
	MOV $-1, X5
	BNE X5, X10, ok

	// Get error code from libc.
	CALL libc_errno(SB)
	MOVW (X10), X10
	MOV X10, (9*8)(X9) // err

	ok:
	RET

	// syscall10 calls a function in libc on behalf of the syscall package.
	// syscall10 takes a pointer to a struct like:
	// struct {
	// fn uintptr
	// a1 uintptr
	// a2 uintptr
	// a3 uintptr
	// a4 uintptr
	// a5 uintptr
	// a6 uintptr
	// a7 uintptr
	// a8 uintptr
	// a9 uintptr
	// a10 uintptr
	// r1 uintptr
	// r2 uintptr
	// err uintptr
	// }
	// syscall10 must be called on the g0 stack with the
	// C calling convention (use libcCall).
	//
	// The openbsd/riscv64 kernel only accepts eight syscall arguments.
	TEXT runtime·syscall10(SB),NOSPLIT,$0
	MOV X10, X9 // pointer to args

	ADD $-16, X2

	MOV (0*8)(X9), X5 // fn
	MOV (1*8)(X9), X10 // a1
	MOV (2*8)(X9), X11 // a2
	MOV (3*8)(X9), X12 // a3
	MOV (4*8)(X9), X13 // a4
	MOV (5*8)(X9), X14 // a5
	MOV (6*8)(X9), X15 // a6
	MOV (7*8)(X9), X16 // a7
	MOV (8*8)(X9), X17 // a8

	JALR X1, X5

	MOV X10, (11*8)(X9) // r1
	MOV X11, (12*8)(X9) // r2

	// Standard libc functions return -1 on error
	// and set errno.
	MOV $-1, X5
	MOVW X10, X11
	BNE X5, X11, ok

	// Get error code from libc.
	CALL libc_errno(SB)
	MOVW (X10), X10
	MOV X10, (13*8)(X9) // err

	ok:
	ADD $16, X2
	RET

	// syscall10X calls a function in libc on behalf of the syscall package.
	// syscall10X takes a pointer to a struct like:
	// struct {
	// fn uintptr
	// a1 uintptr
	// a2 uintptr
	// a3 uintptr
	// a4 uintptr
	// a5 uintptr
	// a6 uintptr
	// a7 uintptr
	// a8 uintptr
	// a9 uintptr
	// a10 uintptr
	// r1 uintptr
	// r2 uintptr
	// err uintptr
	// }
	// syscall10X must be called on the g0 stack with the
	// C calling convention (use libcCall).
	//
	// syscall10X is like syscall10 but expects a 64-bit result
	// and tests for 64-bit -1 to decide there was an error.
	//
	// The openbsd/riscv64 kernel only accepts eight syscall arguments.
	TEXT runtime·syscall10X(SB),NOSPLIT,$0
	MOV X10, X9 // pointer to args

	ADD $-16, X2

	MOV (0*8)(X9), X5 // fn
	MOV (1*8)(X9), X10 // a1
	MOV (2*8)(X9), X11 // a2
	MOV (3*8)(X9), X12 // a3
	MOV (4*8)(X9), X13 // a4
	MOV (5*8)(X9), X14 // a5
	MOV (6*8)(X9), X15 // a6
	MOV (7*8)(X9), X16 // a7
	MOV (8*8)(X9), X17 // a8

	JALR X1, X5

	MOV X10, (11*8)(X9) // r1
	MOV X11, (12*8)(X9) // r2

	// Standard libc functions return -1 on error
	// and set errno.
	MOV $-1, X5
	BNE X5, X10, ok

	// Get error code from libc.
	CALL libc_errno(SB)
	MOVW (X10), X10
	MOV X10, (13*8)(X9) // err

	ok:
	ADD $16, X2
	RET