/* Copyright (C) 1996-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

/* clone() is even more special than fork() as it mucks with stacks

   and invokes a function in the right context after its all over.  */

#include <sysdep.h>

#define _ERRNO_H	1

#include <bits/errno.h>

/* int clone (int (*fn)(void *arg), void *child_stack, int flags, void *arg,

              pid_t *ptid, struct user_desc *tls, pid_t *ctid);

   INCOMING: r5 (fn), r6 (child_stack), r7 (flags), r8 (arg), r9 (ptid)

             r10 (tls), 28 (r1) ctid

   OUTGOING:

   linux: arch/microblaze/entry.S: sys_clone expects

          r5 (flags)  r6 (child stack) r7 (stack_size) r8 (ptid)r9 (ctid)

          r10 (tls)

*/

        .text

ENTRY (__clone)

	addik	r3,r0,-EINVAL

	beqi	r5,SYSCALL_ERROR_LABEL	; // Invalid func

	beqi	r6,SYSCALL_ERROR_LABEL	; // Invalid stack

	addik	r6,r6,-8

	swi	r5,r6,0			; // Push fn onto child's stack

	swi	r8,r6,4			; // Push arg for child

	addk	r5,r0,r7		; // flags for clone() syscall

	addk	r7,r0,r0

	addk	r8,r0,r9		; // parent tid ptr

	lwi	r9,r1,28		; // child tid ptr

	addik	r12,r0,SYS_ify(clone)

	brki	r14,8

	addk	r0,r0,r0

	addik	r4,r0,-4095

	cmpu	r4,r4,r3

	bgei	r4,SYSCALL_ERROR_LABEL

	beqi	r3,L(thread_start)

	rtsd	r15,8

	nop

L(thread_start):

	lwi	r12,r1,0		; // fn

	lwi	r5,r1,4			; // arg

	brald	r15,r12

	nop

	addk	r5,r0,r3

	addik	r12,r0,SYS_ify(exit)

	brki	r14,8

	nop

PSEUDO_END(__clone)

libc_hidden_def (__clone)

weak_alias (__clone,clone)