#__clone(func, stack, flags, arg, ptid, tls, ctid)
#         a0,    a1,   a2,    a3,  a4,  a5,   a6
# sys_clone(flags, stack, ptid, ctid, tls)
#            a0,    a1,   a2,    a3,  a4

.global	__clone
.hidden __clone
.type	__clone,@function
__clone:
	# Save function pointer and argument pointer on new thread stack
	addi.d	$a1, $a1, -16
	st.d	$a0, $a1, 0	# save function pointer
	st.d	$a3, $a1, 8	# save argument pointer
	or	$a0, $a2, $zero
	or	$a2, $a4, $zero
	or	$a3, $a6, $zero
	or	$a4, $a5, $zero
	ori	$a7, $zero, 220
	syscall 0		# call clone

	beqz	$a0, 1f		# whether child process
	jirl	$zero, $ra, 0	# parent process return
1:
	ld.d	$t8, $sp, 0     # function pointer
	ld.d	$a0, $sp, 8     # argument pointer
	jirl	$ra, $t8, 0     # call the user's function
	ori	$a7, $zero, 93
	syscall	0		# child process exit