[RFC,V2,06/10] C-SKY: Linux Syscall Interface

Message ID 34f1011affb007e6cc1e4435ca0bd68f4ff4cfd4.1523169833.git.han_mao@c-sky.com
State New
Headers show
Series
  • port C-SKY to glibc
Related show

Commit Message

Mao Han April 8, 2018, 7:02 a.m.
Contains the Linux system call interface.

        * sysdeps/unix/sysv/linux/csky/____longjmp_chk.S: New file
        * sysdeps/unix/sysv/linux/csky/abiv2_brk.c: New file
        * sysdeps/unix/sysv/linux/csky/abiv2_clone.S: New file
        * sysdeps/unix/sysv/linux/csky/abiv2_getcontext.S: New file
        * sysdeps/unix/sysv/linux/csky/abiv2_setcontext.S: New file
        * sysdeps/unix/sysv/linux/csky/abiv2_syscall.S: New file
        * sysdeps/unix/sysv/linux/csky/abiv2_vfork.S: New file
        * sysdeps/unix/sysv/linux/csky/brk.c: New file
        * sysdeps/unix/sysv/linux/csky/clone.S: New file
        * sysdeps/unix/sysv/linux/csky/ftruncate64.c: New file
        * sysdeps/unix/sysv/linux/csky/getcontext.S: New file
        * sysdeps/unix/sysv/linux/csky/libc-read_tp.S: New file
        * sysdeps/unix/sysv/linux/csky/pt-vfork.S: New file
        * sysdeps/unix/sysv/linux/csky/read_tp.S: New file
        * sysdeps/unix/sysv/linux/csky/readahead.c: New file
        * sysdeps/unix/sysv/linux/csky/scandir64.c: New file
        * sysdeps/unix/sysv/linux/csky/syscall.S: New file
        * sysdeps/unix/sysv/linux/csky/syscalls.list: New file
---
 sysdeps/unix/sysv/linux/csky/____longjmp_chk.S  | 129 ++++++++++++++++++++++++
 sysdeps/unix/sysv/linux/csky/abiv2_brk.c        |  56 ++++++++++
 sysdeps/unix/sysv/linux/csky/abiv2_clone.S      | 106 +++++++++++++++++++
 sysdeps/unix/sysv/linux/csky/abiv2_getcontext.S |  72 +++++++++++++
 sysdeps/unix/sysv/linux/csky/abiv2_setcontext.S |  95 +++++++++++++++++
 sysdeps/unix/sysv/linux/csky/abiv2_syscall.S    |  68 +++++++++++++
 sysdeps/unix/sysv/linux/csky/abiv2_vfork.S      |  45 +++++++++
 sysdeps/unix/sysv/linux/csky/brk.c              |  61 +++++++++++
 sysdeps/unix/sysv/linux/csky/clone.S            |  99 ++++++++++++++++++
 sysdeps/unix/sysv/linux/csky/ftruncate64.c      |  41 ++++++++
 sysdeps/unix/sysv/linux/csky/getcontext.S       | 108 ++++++++++++++++++++
 sysdeps/unix/sysv/linux/csky/libc-read_tp.S     |   1 +
 sysdeps/unix/sysv/linux/csky/pt-vfork.S         |   1 +
 sysdeps/unix/sysv/linux/csky/read_tp.S          |  46 +++++++++
 sysdeps/unix/sysv/linux/csky/readahead.c        |  34 +++++++
 sysdeps/unix/sysv/linux/csky/scandir64.c        |   1 +
 sysdeps/unix/sysv/linux/csky/syscall.S          |  61 +++++++++++
 sysdeps/unix/sysv/linux/csky/syscalls.list      |   7 ++
 18 files changed, 1031 insertions(+)
 create mode 100644 sysdeps/unix/sysv/linux/csky/____longjmp_chk.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/abiv2_brk.c
 create mode 100644 sysdeps/unix/sysv/linux/csky/abiv2_clone.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/abiv2_getcontext.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/abiv2_setcontext.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/abiv2_syscall.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/abiv2_vfork.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/brk.c
 create mode 100644 sysdeps/unix/sysv/linux/csky/clone.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/ftruncate64.c
 create mode 100644 sysdeps/unix/sysv/linux/csky/getcontext.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/libc-read_tp.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/pt-vfork.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/read_tp.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/readahead.c
 create mode 100644 sysdeps/unix/sysv/linux/csky/scandir64.c
 create mode 100644 sysdeps/unix/sysv/linux/csky/syscall.S
 create mode 100644 sysdeps/unix/sysv/linux/csky/syscalls.list

Comments

Arnd Bergmann April 15, 2018, 8:29 p.m. | #1
On Sun, Apr 8, 2018 at 9:02 AM, Mao Han <han_mao@c-sky.com> wrote:

> diff --git a/sysdeps/unix/sysv/linux/csky/syscalls.list b/sysdeps/unix/sysv/linux/csky/syscalls.list
> new file mode 100644
> index 0000000..53cff69
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/csky/syscalls.list
> @@ -0,0 +1,7 @@
> +# File name    Caller  Syscall name    Args    Strong name     Weak names
> +
> +chown          -       chown32         i:sii   __chown         chown
> +cacheflush     -       cacheflush      i:pii   _flush_cache    cacheflush
> +
> +prlimit64      EXTRA   prlimit64       i:iipp  prlimit64
> +fanotify_mark  EXTRA   fanotify_mark   i:iiiiis        fanotify_mark

I can understand the need for the cacheflush syscall here, but why do you need
to override those other three? Shouldn't the defaults be correct for new
architectures?

       Arnd
Mao Han April 16, 2018, 5:54 a.m. | #2
On Sun, Apr 15, 2018 at 10:29:41PM +0200, Arnd Bergmann wrote:
> > diff --git a/sysdeps/unix/sysv/linux/csky/syscalls.list b/sysdeps/unix/sysv/linux/csky/syscalls.list
> > new file mode 100644
> > index 0000000..53cff69
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/csky/syscalls.list
> > @@ -0,0 +1,7 @@
> > +# File name    Caller  Syscall name    Args    Strong name     Weak names
> > +
> > +chown          -       chown32         i:sii   __chown         chown
> > +cacheflush     -       cacheflush      i:pii   _flush_cache    cacheflush
> > +
> > +prlimit64      EXTRA   prlimit64       i:iipp  prlimit64
> > +fanotify_mark  EXTRA   fanotify_mark   i:iiiiis        fanotify_mark
> 
> I can understand the need for the cacheflush syscall here, but why do you need
> to override those other three? Shouldn't the defaults be correct for new
> architectures?
> 
>        Arnd
Thanks for the comment. The default implimentation of the other three are ok
for C-SKY. I'll remove them in syscalls.list.

Best Regards
Mao Han
Adhemerval Zanella April 23, 2018, 11:32 a.m. | #3
On 08/04/2018 04:02, Mao Han wrote:
> diff --git a/sysdeps/unix/sysv/linux/csky/ftruncate64.c b/sysdeps/unix/sysv/linux/csky/ftruncate64.c
> new file mode 100644
> index 0000000..47c38e6
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/csky/ftruncate64.c
> @@ -0,0 +1,41 @@

> +/* Truncate the file FD refers to to LENGTH bytes.  */
> +int
> +__ftruncate64 (int fd, off64_t length)
> +{
> +  unsigned int low = length & 0xffffffff;
> +  unsigned int high = length >> 32;
> +#ifdef __CSKYABIV2__
> +  int result = INLINE_SYSCALL (ftruncate64, 3, fd,
> +			       __LONG_LONG_PAIR (high, low));
> +#else
> +  int result = INLINE_SYSCALL (ftruncate64, 4, fd, 0,
> +			       __LONG_LONG_PAIR (high, low));
> +#endif
> +  return result;
> +}
> +weak_alias (__ftruncate64, ftruncate64)

If I understand correctly the ABIv1 requires oven register for 64 bit argument
passing, which is represented inside glibc as __ASSUME_ALIGNED_REGISTER_PAIRS
set to 1.  So setting it correctly for ABIv1 should make it possible to use
the generic 'sysdeps/unix/sysv/linux/ftruncate64.c' for c-sky.

> diff --git a/sysdeps/unix/sysv/linux/csky/readahead.c b/sysdeps/unix/sysv/linux/csky/readahead.c
> new file mode 100644
> index 0000000..255361c
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/csky/readahead.c
> @@ -0,0 +1,34 @@

> +
> +ssize_t
> +__readahead (int fd, off64_t offset, size_t count)
> +{
> +  return INLINE_SYSCALL_CALL (readahead, fd,
> +                              __ALIGNMENT_ARG SYSCALL_LL64 (offset), count);
> +}
> +
> +weak_alias (__readahead, readahead)

I just sent a patch to consolidate Linux readahead implementation [1]. So most
likely this new arch-specific file for c-sky would be unnecessary. 


> diff --git a/sysdeps/unix/sysv/linux/csky/scandir64.c b/sysdeps/unix/sysv/linux/csky/scandir64.c
> new file mode 100644
> index 0000000..506fd88
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/csky/scandir64.c
> @@ -0,0 +1 @@
> +#include <sysdeps/unix/sysv/linux/i386/scandir64.c>

The 'scandir{at}{64}' consolidation is pushed upstream [2], so this file should
be unnecessary as well.

[1] https://sourceware.org/ml/libc-alpha/2018-04/msg00471.html
[2] https://sourceware.org/git/?p=glibc.git;a=commit;h=c0123b3b1118419210879e935620eb2ad987c2f1
Mao Han April 26, 2018, 7:39 a.m. | #4
Hi,
Thanks for the comment.
On Mon, Apr 23, 2018 at 08:32:16AM -0300, Adhemerval Zanella wrote:
> > +#ifdef __CSKYABIV2__
> > +  int result = INLINE_SYSCALL (ftruncate64, 3, fd,
> > +			       __LONG_LONG_PAIR (high, low));
> > +#else
> > +  int result = INLINE_SYSCALL (ftruncate64, 4, fd, 0,
> > +			       __LONG_LONG_PAIR (high, low));
> > +#endif
> > +  return result;
> > +}
> > +weak_alias (__ftruncate64, ftruncate64)
> 
> If I understand correctly the ABIv1 requires oven register for 64 bit argument
> passing, which is represented inside glibc as __ASSUME_ALIGNED_REGISTER_PAIRS
> set to 1.  So setting it correctly for ABIv1 should make it possible to use
> the generic 'sysdeps/unix/sysv/linux/ftruncate64.c' for c-sky.
>
OK, I'll try the macro and the generic implementation.
 
> > +
> > +ssize_t
> > +__readahead (int fd, off64_t offset, size_t count)
> > +{
> > +  return INLINE_SYSCALL_CALL (readahead, fd,
> > +                              __ALIGNMENT_ARG SYSCALL_LL64 (offset), count);
> > +}
> > +
> > +weak_alias (__readahead, readahead)
> 
> I just sent a patch to consolidate Linux readahead implementation [1]. So most
> likely this new arch-specific file for c-sky would be unnecessary. 
> 
> 
> > +++ b/sysdeps/unix/sysv/linux/csky/scandir64.c
> > @@ -0,0 +1 @@
> > +#include <sysdeps/unix/sysv/linux/i386/scandir64.c>
> 
> The 'scandir{at}{64}' consolidation is pushed upstream [2], so this file should
> be unnecessary as well.
> 
> [1] https://sourceware.org/ml/libc-alpha/2018-04/msg00471.html
> [2] https://sourceware.org/git/?p=glibc.git;a=commit;h=c0123b3b1118419210879e935620eb2ad987c2f1
OK, I'll change to the consolidated implementation.

Best Regards,
Mao Han

Patch

diff --git a/sysdeps/unix/sysv/linux/csky/____longjmp_chk.S b/sysdeps/unix/sysv/linux/csky/____longjmp_chk.S
new file mode 100644
index 0000000..7e50d92
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/____longjmp_chk.S
@@ -0,0 +1,129 @@ 
+/* Copyright (C) 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/>.  */
+
+#include <sysdep.h>
+
+	.section .rodata.str1.8,"aMS",@progbits,1
+	.align  2
+	.type   longjmp_msg,@object
+longjmp_msg:
+	.string "longjmp causes uninitialized stack frame"
+	.size   longjmp_msg, .-longjmp_msg
+	.text
+
+#define __longjmp ____longjmp_chk
+
+#ifdef	__PIC__
+# ifdef	__CSKYABIV2__
+#  define CALL_FAIL	\
+	subi    sp, 8;						\
+	stw     gb, (sp, 0);					\
+	grs     gb, .Lgetpc1;					\
+.Lgetpc1:							\
+	lrw     t0, .Lgetpc1@GOTPC;				\
+	addu	gb, gb, t0;					\
+	lrw     a0, longjmp_msg@GOTOFF;				\
+	addu	a0, a0, gb;					\
+	lrw     t0, (HIDDEN_JUMPTARGET(__fortify_fail))@PLT;	\
+	ldr.w	t0, (gb, t0 << 0);				\
+	jsr     t0;						\
+	ldw     gb, (sp, 0);					\
+	addi    sp, 8;
+# else /* __CSKYABIV2__ */
+#  define CALL_FAIL	\
+	subi    sp, 8;						\
+	stw     gb, (sp);					\
+	stw     r15, (sp, 4);					\
+	bsr     .Lgetpc2;					\
+.Lgetpc2:							\
+	lrw     gb, .Lgetpc2@GOTPC;				\
+	add     gb, r15;					\
+	lrw     a0, longjmp_msg@GOTOFF;				\
+	addu	a0, gb;						\
+	lrw     r7, (HIDDEN_JUMPTARGET(__fortify_fail))@PLT;	\
+	add     r7, gb;						\
+	ldw     r7, (r7);					\
+	jsr     r7;						\
+	ldw     gb, (sp, 0);					\
+	ldw     r15,(sp, 4);					\
+	addi    sp, 8;
+# endif /* __CSKYABIV2__ */
+#else /* __PIC__ */
+# define CALL_FAIL	\
+	lrw     a0, longjmp_msg;				\
+	jsri    HIDDEN_JUMPTARGET(__fortify_fail);
+#endif/* __PIC__ */
+
+#ifdef	__CSKYABIV2__
+# define  CHECK_SP(reg)	\
+	cmplt   sp, reg;					\
+	bt      .Lok1;						\
+	mov     r9, a0;						\
+	mov     t0, r7;						\
+	lrw     r7, __NR_sigaltstack;				\
+	movi	a0, 0;						\
+	subi	sp, 12;	/* sizeof (stack_t) */			\
+	mov     a1, sp;						\
+	trap    0;						\
+	mov     r7, t0;						\
+	cmpnei  a0, 0;						\
+	bt      .Lok;						\
+	ldw     a1, (sp, 4);					\
+	btsti   a1, 1;						\
+	bt      .Lfail;						\
+	ldw     a1, (sp, 0);					\
+	ldw     a3, (sp, 8);					\
+	add     a1, a3;						\
+	sub     a1, reg;					\
+	cmphs   a1, a3;						\
+	bt      .Lok;						\
+.Lfail:								\
+	addi    sp, 12;						\
+	CALL_FAIL						\
+.Lok:								\
+	mov     a0, r9;						\
+.Lok1:
+#else
+# define  CHECK_SP(reg)	\
+	cmplt   sp, reg;					\
+	bt      .Lok1;						\
+	mov     r9, a0;						\
+	lrw     r1, __NR_sigaltstack;				\
+	movi	a0, 0;						\
+	subi	sp, 12;	/* sizeof (stack_t) */			\
+	mov     a1, sp;						\
+	trap    0;						\
+	cmpnei  a0, 0;						\
+	bt      .Lok;						\
+	ldw     a1, (sp, 4);					\
+	btsti   a1, 1;						\
+	bt      .Lfail;						\
+	ldw     a1, (sp, 0);					\
+	ldw     a3, (sp, 8);					\
+	add     a1, a3;						\
+	sub     a1, reg;					\
+	cmphs   a1, a3;						\
+	bt      .Lok;						\
+.Lfail:								\
+	addi    sp, 12;						\
+	CALL_FAIL						\
+.Lok:								\
+	mov     a0, r9;						\
+.Lok1:
+#endif
+
+#include <__longjmp.S>
diff --git a/sysdeps/unix/sysv/linux/csky/abiv2_brk.c b/sysdeps/unix/sysv/linux/csky/abiv2_brk.c
new file mode 100644
index 0000000..a564276
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/abiv2_brk.c
@@ -0,0 +1,56 @@ 
+/* brk system call for Linux/C-SKY.
+   Copyright (C) 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/>.  */
+
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <errno.h>
+
+/* This must be initialized data because commons can't have aliases.  */
+void * __curbrk = 0;
+
+/* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
+   to work around different old braindamage in the old Linux/x86 ELF
+   dynamic linker.  Sigh.  */
+weak_alias (__curbrk, ___brk_addr)
+
+int __brk (void *addr)
+{
+    void *newbrk;
+
+    {
+      register long int res __asm__("a0") = (long int)addr;
+
+      __asm__ volatile ("lrw l3, %1\n\t"
+                        "trap 0     \n\t"
+                        :"+r" (res)
+                        :"i" (__NR_brk)
+                        :"l3");
+      newbrk = (void *) res;
+    }
+    __curbrk = newbrk;
+
+    if (newbrk < addr)
+    {
+        __set_errno (ENOMEM);
+	return -1;
+    }
+
+    return 0;
+}
+
+weak_alias (__brk, brk)
diff --git a/sysdeps/unix/sysv/linux/csky/abiv2_clone.S b/sysdeps/unix/sysv/linux/csky/abiv2_clone.S
new file mode 100644
index 0000000..bebde43
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/abiv2_clone.S
@@ -0,0 +1,106 @@ 
+/* Copyright (C) 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>
+#include <csky_readtp.h>
+
+#define CLONE_VM      8  /* 8 makes btsti easier, 0x00000100 in real */
+#define CLONE_THREAD  16  /* 0x00010000 in real */
+
+/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
+	     pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
+
+        .text
+ENTRY(__clone)
+	/* Sanity check arguments.  */
+	cmpnei	a0, 0		/* no NULL function pointers */
+	bf	__error_arg
+	cmpnei	a1, 0		/* no NULL function pointers */
+	bf	__error_arg
+
+	subi	a1, 8
+	stw	a0, (a1, 0)	/* insert the args onto the new stack */
+	stw	a3, (a1, 4)	/* insert the args onto the new stack */
+
+	mov	t1, r7		/* save r7 */
+	mov	t2, r4		/* save r4 (has t2 ?)*/
+
+	mov	a0, a2		/* arg1 = flags */
+	ldw	a2, (sp, 0)	/* arg3 = ptid */
+	ldw	a3, (sp, 8)	/* arg4 = ctid */
+	ldw	r4, (sp, 4)	/* arg5 = tls */
+	lrw	r7, __NR_clone
+	trap	0
+
+	mov	r7, t1		/* restore r7 */
+	mov	r4, t2		/* restore r4 */
+	btsti	a0, 31		/* is a0 less than zero? */
+	bt	do_syscall_error
+	cmpnei	a0, 0
+	bf	1f
+	rts
+PSEUDO_END (__clone)
+
+1:
+	ldw	a0, (sp, 4)	/* restore args from new sp */
+	ldw	a1, (sp, 0)	/* restore args from new sp */
+	addi	sp, 8
+	jsr	a1
+
+	/* exit */
+#ifdef __PIC__
+        grs     t1, .Lgetpc1
+.Lgetpc1:
+        lrw     t0, .Lgetpc1@GOTPC
+        addu    t1, t1, t0
+        lrw     t0, _exit@GOT
+        ldr.w   t0, (t1, t0 << 0)
+#else
+        lrw     t0, _exit       /* exit */
+#endif /* __PIC__ */
+        jmp     t0
+
+__error_arg:
+	lrw	a0, -EINVAL
+
+do_syscall_error:
+#ifdef __PIC__
+	subi	sp, 8
+	stw	gb, (sp, 0)
+	stw	r15, (sp, 4)
+	grs	gb, .Lgetpc2
+.Lgetpc2:
+	lrw	t0, .Lgetpc2@GOTPC
+	addu	gb, gb, t0
+	lrw	t0, __syscall_error@PLT
+	ldr.w	t0, (gb, t0 << 0)
+	jsr	t0
+	ldw	gb, (sp, 0)
+	ldw	r15, (sp, 4)
+	addi	sp, 8
+#else
+	jmpi	__syscall_error
+#endif /* __PIC__ */
+	rts
+
+libc_hidden_def (__clone)
+weak_alias (__clone, clone)
diff --git a/sysdeps/unix/sysv/linux/csky/abiv2_getcontext.S b/sysdeps/unix/sysv/linux/csky/abiv2_getcontext.S
new file mode 100644
index 0000000..c85cbac
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/abiv2_getcontext.S
@@ -0,0 +1,72 @@ 
+/* Copyright (C) 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/>.  */
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+/* int getcontext (ucontext_t *ucp) */
+
+ENTRY(__getcontext)
+	/* No need to save r2-r7 or a0-a3 */
+	mov	t0, a0
+
+	addi	a0, MCONTEXT_CSKY_R4
+
+	stm	r4-r13, (a0)			/* save r4-r13 */
+	stw	sp, (t0, MCONTEXT_CSKY_SP)	/* save sp */
+	stw	r15, (t0, MCONTEXT_CSKY_LR)	/* save lr */
+	stw	r15, (t0, MCONTEXT_CSKY_PC)	/* Return to PC */
+	addi	a0, t0, MCONTEXT_CSKY_R16
+	stm	r16-r31, (a0)			/* save r16-r31 */
+	movi	a0, 0
+	stw	a0, (t0, MCONTEXT_CSKY_A0)	/* Return zero */
+
+	subi	sp, 8
+	stw	t0, (sp, 0)			/* save t0 after "save sp" */
+
+	/* __sigprocmask(SIG_BLOCK, NULL, &(ucontext->uc_sigmask)) */
+	movi	a0, SIG_BLOCK
+	movi	a1, 0
+	addi	a2, t0, UCONTEXT_SIGMASK
+
+	/* do sigprocmask syscall */
+#ifdef __PIC__
+	subi	sp, 8
+	stw	gb, (sp, 0)
+	grs	gb, .Lgetpc
+.Lgetpc:
+	lrw	a3, .Lgetpc@GOTPC
+	addu	gb, gb, a3
+	lrw	a3, __sigprocmask@PLT
+	ldr.w	a3, (gb, a3 << 0)
+	jsr	a3
+	ldw	gb, (sp, 0)
+	addi	sp, 8
+#else
+	jsri    __sigprocmask
+#endif
+
+	ldw	t0, (sp, 0)
+	addi	sp, 8
+	/* restore r15 for sigprocmask changes*/
+	ldw	r15, (t0, MCONTEXT_CSKY_LR)
+	movi	a0, 0				/* return 0 */
+	jmp	r15
+END(__getcontext)
+
+weak_alias(__getcontext, getcontext)
diff --git a/sysdeps/unix/sysv/linux/csky/abiv2_setcontext.S b/sysdeps/unix/sysv/linux/csky/abiv2_setcontext.S
new file mode 100644
index 0000000..50c47eb
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/abiv2_setcontext.S
@@ -0,0 +1,95 @@ 
+/* Copyright (C) 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/>.  */
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+/* int setcontext (const ucontext_t *ucp) */
+
+ENTRY(__setcontext)
+	mov	t0, a0
+	subi	sp, 8
+	stw	a0, (sp, 0)
+
+	/* set sigmask */
+	movi	a0, SIG_SETMASK
+	addi	a1, t0, UCONTEXT_SIGMASK
+	movi	a2, 0
+
+	/* do sigprocmask syscall */
+#ifdef __PIC__
+	subi	sp, 8
+	stw	gb, (sp, 0)
+	grs	gb, .Lgetpc1
+.Lgetpc1:
+	lrw	a3, .Lgetpc1@GOTPC
+	addu	gb, gb, a3
+	lrw	a3, __sigprocmask@PLT
+	ldr.w	a3, (gb, a3 << 0)
+	jsr	a3
+	ldw	gb, (sp, 0)
+	addi	sp, 8
+#else
+	jsri	__sigprocmask
+#endif /* __PIC__ */
+
+	ldw	t0, (sp, 0)
+	addi	sp, 8
+	/* set r0-r11. Load a0-a3, for makecontext requires */
+	addi	t1, t0, MCONTEXT_CSKY_A0
+	ldm	r0-r11, (t1)
+	ldw	sp, (t0, MCONTEXT_CSKY_SP)	/* load sp */
+	ldw	r15, (t0, MCONTEXT_CSKY_LR)	/* load lr */
+	ldw	t0, (t0, MCONTEXT_CSKY_PC)	/* load start addr */
+	jmp	t0
+END(setcontext)
+weak_alias(__setcontext, setcontext)
+
+ENTRY(__startcontext)
+	mov	a0, r9
+	cmpnei	r9, 0	/* r9 was set in makecontext */
+	bf	1f	/* null, then exit */
+
+	/* call setcontext */
+#ifdef __PIC__
+	grs	t1, .Lgetpc2
+.Lgetpc2:
+	lrw	t0, .Lgetpc2@GOTPC
+	addu	t1, t1, t0
+	lrw	t0, __setcontext@GOT
+	ldr.w	t0, (t1, t0 << 0)
+#else
+	lrw	t0, __setcontext
+#endif
+	jsr	t0
+
+1:
+	/* call _exit */
+#ifdef __PIC__
+	grs	t1, .Lgetpc3
+.Lgetpc3:
+	lrw	t0, .Lgetpc3@GOTPC
+	addu	t1, t1, t0
+	lrw	t0, _exit@GOT
+	ldr.w	t0, (t1, t0 << 0)
+#else
+	lrw	t0, _exit
+#endif
+	jsr	t0
+
+END(__startcontext)
diff --git a/sysdeps/unix/sysv/linux/csky/abiv2_syscall.S b/sysdeps/unix/sysv/linux/csky/abiv2_syscall.S
new file mode 100644
index 0000000..d1d1cb3
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/abiv2_syscall.S
@@ -0,0 +1,68 @@ 
+/* Copyright (C) 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/>.  */
+
+#include <sysdep.h>
+
+/* long syscall(long sysnum, long a, long b, long c, long d, long e, long f) */
+
+ENTRY (syscall)
+	subi	sp, 8
+	stw	r4, (sp, 0)
+	stw	r5, (sp, 4)
+
+	mov	t0, r7
+	mov	r7, a0		/* r7 = sysnum */
+
+	mov	a0, a1		/* arg1 = a */
+	mov	a1, a2		/* arg2 = b */
+	mov	a2, a3		/* arg3 = c */
+	ldw	a3, (sp, 8)	/* arg4 = d */
+	ldw	r4, (sp, 12)	/* arg5 = e */
+	ldw	r5, (sp, 16)	/* arg6 = f */
+	trap	0
+
+	mov	r7, t0
+
+	ldw	r4, (sp, 0)
+	ldw	r5, (sp, 4)
+	addi	sp, 8
+
+	lrw	t0, 0xfffff000
+	cmphs	a0, t0
+	bt	do_syscall_error
+	rts
+PSEUDO_END (syscall)
+
+do_syscall_error:
+#ifdef __PIC__
+	subi	sp, 8
+	stw	gb, (sp, 0)
+        stw     lr, (sp, 4)
+	grs	gb, .Lgetpc
+.Lgetpc:
+	lrw	t0, .Lgetpc@GOTPC
+	addu	gb, gb, t0
+	lrw	t0, __syscall_error@PLT
+	ldr.w	t0, (gb, t0 << 0)
+	jsr	t0
+	ldw	gb, (sp, 0)
+        ldw     lr, (sp, 4)
+	addi	sp, 8
+#else
+	jmpi	__syscall_error
+#endif /* __PIC__ */
+	rts
diff --git a/sysdeps/unix/sysv/linux/csky/abiv2_vfork.S b/sysdeps/unix/sysv/linux/csky/abiv2_vfork.S
new file mode 100644
index 0000000..88cdc8a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/abiv2_vfork.S
@@ -0,0 +1,45 @@ 
+/* Copyright (C) 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/>.  */
+
+#include <sysdep.h>
+#define _ERRNO_H	1
+#include <bits/errno.h>
+
+/* Clone the calling process, but without copying the whole address space.
+   The calling process is suspended until the new process exits or is
+   replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
+   and the process ID of the new process to the old process.  */
+
+ENTRY (__vfork)
+#ifdef SAVE_PID
+	SAVE_PID
+#endif
+	mov	t0, r7
+	lrw	r7, __NR_vfork
+	trap	0
+	mov	r7, t0
+#ifdef RESTORE_PID
+	RESTORE_PID
+#endif
+	PSEUDO_RET
+	rts
+
+PSEUDO_END (__vfork)
+libc_hidden_def (__vfork)
+
+weak_alias (__vfork, vfork)
+strong_alias (__vfork, __libc_vfork)
diff --git a/sysdeps/unix/sysv/linux/csky/brk.c b/sysdeps/unix/sysv/linux/csky/brk.c
new file mode 100644
index 0000000..00d42c2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/brk.c
@@ -0,0 +1,61 @@ 
+/* brk system call for Linux/C-SKY.
+   Copyright (C) 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/>.  */
+
+#ifdef __CSKYABIV2__
+# include "abiv2_brk.c"
+#else
+
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <errno.h>
+
+/* This must be initialized data because commons can't have aliases.  */
+void * __curbrk = 0;
+
+/* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
+   to work around different old braindamage in the old Linux/x86 ELF
+   dynamic linker.  Sigh.  */
+weak_alias (__curbrk, ___brk_addr)
+
+int __brk (void *addr)
+{
+    void *newbrk;
+
+    {
+      register long int res __asm__("r2") = (long int)addr;
+
+      __asm__ volatile ("lrw  r1, %1\n\t"
+                        "trap 0\n\t"
+                        :"+r" (res)
+                        :"i" (__NR_brk) :"r1");
+      newbrk = (void *) res;
+    }
+    __curbrk = newbrk;
+
+    if (newbrk < addr)
+    {
+        __set_errno (ENOMEM);
+	return -1;
+    }
+
+    return 0;
+}
+
+weak_alias (__brk, brk)
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/csky/clone.S b/sysdeps/unix/sysv/linux/csky/clone.S
new file mode 100644
index 0000000..38531f9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/clone.S
@@ -0,0 +1,99 @@ 
+/* Copyright (C) 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.  */
+
+#ifdef	__CSKYABIV2__
+# include "abiv2_clone.S"
+#else
+
+# include <sysdep.h>
+# define _ERRNO_H	1
+# include <bits/errno.h>
+# include <csky_readtp.h>
+
+# define CLONE_VM      8  /* 11 makes btsti easier, 0x00000100 in real */
+# define CLONE_THREAD  16  /* 0x00010000 in real */
+
+/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
+	     pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
+
+        .text
+ENTRY(__clone)
+	/* Sanity check arguments. */
+	cmpnei	r2, 0
+	bf	__error_arg	/* no NULL function pointers */
+	cmpnei	r3, 0
+	bf	__error_arg	/* no NULL function pointers */
+
+	subi	r3, 8
+	stw	r2, (r3, 0)	/* insert the args onto the new stack */
+	stw	r5, (r3, 4)	/* insert the args onto the new stack */
+
+	ldw	r5, (sp, 0)	/* arg4 = ctid */
+
+	mov	r2, r4		/* arg1 = flags */
+	mov	r4, r6		/* arg3 = ptid */
+	mov	r6, r7		/* arg5 = tls */
+	lrw	r1, __NR_clone	/* do syscall */
+	trap	0
+
+	btsti	r2, 31		/* is r2 less than zero? */
+	bt	do_syscall_error
+	cmpnei	r2, 0
+	bf	1f
+	rts
+PSEUDO_END (__clone)
+
+1:
+	ldw	r2, (sp, 4)	/* restore args from new sp */
+	ldw	r3, (sp, 0)	/* restore args from new sp */
+	addi	sp, 8
+
+	jsr	r3
+	lrw	r1, __NR_exit
+	trap	0
+
+__error_arg:
+	lrw	r2, -EINVAL
+
+do_syscall_error:
+# ifdef __PIC__
+	subi	sp, 8
+	stw	gb, (sp, 0)
+	stw	r15, (sp, 4)
+	bsr	.Lgetpc
+.Lgetpc:
+	lrw	gb, .Lgetpc@GOTPC
+	addu	gb, r15
+	lrw	r7, __syscall_error@PLT
+	addu	r7, gb
+	ldw	r7, (r7)
+	jsr	r7
+	ldw	gb, (sp, 0)
+	ldw	r15, (sp, 4)
+	addi	sp, 8
+# else
+	jmpi	 __syscall_error
+# endif /* __PIC__ */
+	rts
+
+libc_hidden_def (__clone)
+weak_alias (__clone, clone)
+
+#endif	/* __CSKYABIV2__*/
diff --git a/sysdeps/unix/sysv/linux/csky/ftruncate64.c b/sysdeps/unix/sysv/linux/csky/ftruncate64.c
new file mode 100644
index 0000000..47c38e6
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/ftruncate64.c
@@ -0,0 +1,41 @@ 
+/* Copyright (C) 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/>.  */
+
+#include <sys/types.h>
+#include <errno.h>
+#include <endian.h>
+#include <unistd.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+
+/* Truncate the file FD refers to to LENGTH bytes.  */
+int
+__ftruncate64 (int fd, off64_t length)
+{
+  unsigned int low = length & 0xffffffff;
+  unsigned int high = length >> 32;
+#ifdef __CSKYABIV2__
+  int result = INLINE_SYSCALL (ftruncate64, 3, fd,
+			       __LONG_LONG_PAIR (high, low));
+#else
+  int result = INLINE_SYSCALL (ftruncate64, 4, fd, 0,
+			       __LONG_LONG_PAIR (high, low));
+#endif
+  return result;
+}
+weak_alias (__ftruncate64, ftruncate64)
diff --git a/sysdeps/unix/sysv/linux/csky/getcontext.S b/sysdeps/unix/sysv/linux/csky/getcontext.S
new file mode 100644
index 0000000..447c15b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/getcontext.S
@@ -0,0 +1,108 @@ 
+/* Copyright (C) 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/>.  */
+
+#ifdef __CSKYABIV2__
+#include "abiv2_getcontext.S"
+#else
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+/* int getcontext (ucontext_t *ucp) */
+
+ENTRY(__getcontext)
+	/* No need to save r2-r7 or a0-a3 */
+	mov	r7, r2
+
+	/* return zero */
+	lrw	r2, MCONTEXT_CSKY_A0
+	add	r2, r7
+	movi	r1, 0
+	stw	r1, (r2)
+
+	lrw	r2, MCONTEXT_CSKY_R8
+	add	r2, r7
+	stw	r8, (r2, 0)			/* save r8 */
+	stw	r9, (r2, 4)			/* save r9 */
+	stw	r10, (r2, 8)			/* save r10 */
+	stw	r11, (r2, 12)			/* save r11 */
+	stw	r12, (r2, 16)			/* save r12 */
+	stw	r13, (r2, 20)			/* save r13 */
+	stw	r14, (r2, 24)			/* save r14 */
+	stw	r15, (r2, 28)			/* save lr */
+
+
+	lrw	r2, MCONTEXT_CSKY_SP
+	add	r2, r7
+	stw	sp, (r2)			/* save sp */
+
+	lrw	r2, MCONTEXT_CSKY_LR
+	add	r2, r7
+	stw	r15, (r2)			/* Return to LR */
+
+	lrw	r2, MCONTEXT_CSKY_PC
+	add	r2, r7
+	stw	r15, (r2)			/* Return to LR */
+
+	lrw	r2, MCONTEXT_CSKY_A0
+	add	r2, r7
+	movi	r3, 0
+	stw	r3, (r2)			/* Return zero */
+
+	/* __sigprocmask(SIG_BLOCK, NULL, &(ucontext->uc_sigmask)) */
+	lrw	r2, SIG_BLOCK
+	movi	r3, 0
+	lrw	r4, UCONTEXT_SIGMASK
+	add	r4, r7
+
+	subi	sp, 8
+	stw	r7, (sp, 0)
+
+	/* do sigprocmask syscall */
+#ifdef __PIC__
+	subi	sp, 8
+	stw	gb, (sp, 0)
+	stw	lr, (sp, 4)
+	bsr	.Lgetpc
+.Lgetpc:
+	lrw	gb, .Lgetpc@GOTPC
+	addu	gb, r15
+	lrw	r7, __sigprocmask@PLT
+	addu	r7, gb
+	ldw	r7, (r7)
+	jsr	r7
+	ldw	gb, (sp, 0)
+	ldw	lr, (sp, 4)
+	addi	sp, 8
+#else
+        jsri	__sigprocmask
+#endif
+
+	ldw	r7, (sp, 0)
+	addi	sp, 8
+	lrw	r2, MCONTEXT_CSKY_LR
+	add	r2, r7
+	/* restore r15 for sigprocmask changes */
+	ldw	r15, (r2)
+	movi	r2, 0				/* return 0 */
+	jmp	r15
+END(__getcontext)
+
+weak_alias(__getcontext, getcontext)
+
+#endif	/* __CSKYABIV2__*/
diff --git a/sysdeps/unix/sysv/linux/csky/libc-read_tp.S b/sysdeps/unix/sysv/linux/csky/libc-read_tp.S
new file mode 100644
index 0000000..ca9d2b8
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/libc-read_tp.S
@@ -0,0 +1 @@ 
+#include <read_tp.S>
diff --git a/sysdeps/unix/sysv/linux/csky/pt-vfork.S b/sysdeps/unix/sysv/linux/csky/pt-vfork.S
new file mode 100644
index 0000000..65cc382
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/pt-vfork.S
@@ -0,0 +1 @@ 
+#include <sysdeps/unix/sysv/linux/alpha/pt-vfork.S>
diff --git a/sysdeps/unix/sysv/linux/csky/read_tp.S b/sysdeps/unix/sysv/linux/csky/read_tp.S
new file mode 100644
index 0000000..dc403da
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/read_tp.S
@@ -0,0 +1,46 @@ 
+/* Copyright (C) 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/>.  */
+
+#include <features.h>
+#include <sysdep.h>
+
+/* This function is exported from libc for use by user code.  libpthread, librt,
+   and the dynamic linker get their own private copies, for
+   performance (and in the case of ld.so, out of necessity); those are
+   all hidden.  */
+
+/*
+ * __read_tp
+ * clobbe r0, others had to be saved
+ *
+ */
+#if IS_IN (libc)
+	.global __read_tp
+#else
+	.hidden __read_tp
+#endif
+#ifdef __CSKYABIV2__
+ENTRY (__read_tp)
+	mov	r0, r31
+	rts
+END (__read_tp)
+#else
+ENTRY (__read_tp)
+	trap	3
+	rts
+END (__read_tp)
+#endif
diff --git a/sysdeps/unix/sysv/linux/csky/readahead.c b/sysdeps/unix/sysv/linux/csky/readahead.c
new file mode 100644
index 0000000..255361c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/readahead.c
@@ -0,0 +1,34 @@ 
+/* Provide kernel hint to read ahead.
+   Copyright (C) 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/>.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <endian.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+
+ssize_t
+__readahead (int fd, off64_t offset, size_t count)
+{
+  return INLINE_SYSCALL_CALL (readahead, fd,
+                              __ALIGNMENT_ARG SYSCALL_LL64 (offset), count);
+}
+
+weak_alias (__readahead, readahead)
diff --git a/sysdeps/unix/sysv/linux/csky/scandir64.c b/sysdeps/unix/sysv/linux/csky/scandir64.c
new file mode 100644
index 0000000..506fd88
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/scandir64.c
@@ -0,0 +1 @@ 
+#include <sysdeps/unix/sysv/linux/i386/scandir64.c>
diff --git a/sysdeps/unix/sysv/linux/csky/syscall.S b/sysdeps/unix/sysv/linux/csky/syscall.S
new file mode 100644
index 0000000..9b700a3
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/syscall.S
@@ -0,0 +1,61 @@ 
+/* Copyright (C) 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/>.  */
+
+#ifdef __CSKYABIV2__
+# include "abiv2_syscall.S"
+#else
+
+# include <sysdep.h>
+
+ENTRY (syscall)
+	mov	r1, r2		/* syscall num */
+
+	mov	r2, r3		/* arg1 */
+	mov	r3, r4		/* arg2 */
+	mov	r4, r5		/* arg3 */
+	mov	r5, r6		/* arg4*/
+	mov	r6, r7		/* arg5*/
+	ld	r7, (sp, 0)	/* arg6 */
+	trap	0
+	lrw	r3, 0xfffff000
+	cmphs	r2, r3
+	bt	do_syscall_error
+	rts
+PSEUDO_END (syscall)
+
+do_syscall_error:
+# ifdef __PIC__
+	subi	sp, 8
+	stw	gb, (sp, 0)
+	stw	r15, (sp, 4)
+	bsr	.Lgetpc
+.Lgetpc:
+	lrw	gb, .Lgetpc@GOTPC
+	addu	gb, r15
+	lrw	r7, __syscall_error@PLT
+	addu	r7, gb
+	ldw	r7, (r7)
+	jsr	r7
+	ldw	gb, (sp, 0)
+	ldw	r15, (sp, 4)
+	addi	sp, 8
+# else
+	jmpi	__syscall_error
+# endif /* __PIC__ */
+	rts
+
+#endif /* __CSKYABVI2__ */
diff --git a/sysdeps/unix/sysv/linux/csky/syscalls.list b/sysdeps/unix/sysv/linux/csky/syscalls.list
new file mode 100644
index 0000000..53cff69
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/syscalls.list
@@ -0,0 +1,7 @@ 
+# File name	Caller	Syscall name	Args	Strong name	Weak names
+
+chown		-	chown32		i:sii	__chown		chown
+cacheflush	-	cacheflush	i:pii	_flush_cache	cacheflush
+
+prlimit64	EXTRA	prlimit64	i:iipp	prlimit64
+fanotify_mark	EXTRA	fanotify_mark	i:iiiiis	fanotify_mark