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authorWaldemar Brodkorb <wbx@openadk.org>2016-05-28 18:12:58 +0200
committerWaldemar Brodkorb <wbx@uclibc-ng.org>2016-11-04 00:03:07 +0100
commitb8fcdddcbb192fc367ff04bbd753b9deb69b09f3 (patch)
tree8febdb9d4e3d090e9273c29df9ff06116196c8e4 /libc/sysdeps/linux/nios2/clone.S
parent191739597c6d380692885cfdd8dd8aa4f31f029d (diff)
nios2: sync support with glibc
Only static linking is supported for now. More debugging and analyzing for ld.so, TLS and NPTL is required. But at least you can bootup a static root fileystem in Qemu.
Diffstat (limited to 'libc/sysdeps/linux/nios2/clone.S')
-rw-r--r--libc/sysdeps/linux/nios2/clone.S152
1 files changed, 88 insertions, 64 deletions
diff --git a/libc/sysdeps/linux/nios2/clone.S b/libc/sysdeps/linux/nios2/clone.S
index 4afcb7d75..0626d8aa2 100644
--- a/libc/sysdeps/linux/nios2/clone.S
+++ b/libc/sysdeps/linux/nios2/clone.S
@@ -1,70 +1,94 @@
-/*
- * libc/sysdeps/linux/nios2/clone.S -- `clone' syscall for linux/nios2
- *
- * Copyright (C) 2004 Microtronix Datacom Ltd
- *
- * This file is subject to the terms and conditions of the GNU Lesser
- * General Public License. See the file COPYING.LIB in the main
- * directory of this archive for more details.
- *
- * Written by Wentao Xu <wentao@microtronix.com>
- */
-
-#define _ERRNO_H
+/* clone() implementation for Nios II.
+ Copyright (C) 2008-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Andrew Jenner <andrew@codesourcery.com>, 2008.
+
+ 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 <sys/syscall.h>
-
-#ifdef __NR_clone
-/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
-
-.text
-.global clone
-.type clone,%function
-.align 4
-clone:
- addi sp,sp,-8
- mov r8,r4
- stw ra,4(sp)
- stw r16,0(sp)
-
- mov r4,r6
- movi r2,-EINVAL
-
- /* sanity check */
- beq r8,zero,CLONE_ERROR_LABEL
- beq r5,zero,CLONE_ERROR_LABEL
-
- /* system call */
- movi r2,TRAP_ID_SYSCALL
- movi r3,__NR_clone
- trap
-
- /* child call the function */
- mov r4,r7
- bne r2,zero,CLONE_ERROR_LABEL
- callr r8
-
- /* exit if it returns */
- mov r4,r2
- movi r3,__NR_exit
+
+#ifdef __UCLIBC_HAS_THREADS_NATIVE__
+#include <tcb-offsets.h>
+#endif
+
+#define CLONE_VM 0x00000100
+
+/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
+ void *parent_tidptr, void *tls, void *child_tidptr) */
+
+ .text
+ENTRY(__clone)
+ /* Sanity check arguments. */
+ movi r2, EINVAL
+
+ subi r5, r5, 8 /* Reserve argument save space. */
+ stw r4, 4(r5) /* Save function pointer. */
+ stw r7, 0(r5) /* Save argument pointer. */
+
+ /* Load arguments. */
+ mov r4, r6
+ ldw r6, 0(sp)
+ ldw r7, 8(sp)
+ ldw r8, 4(sp)
+
+ /* Do the system call. */
+ movi r2, SYS_ify (clone)
+
trap
-
-CLONE_ERROR_LABEL:
- movi r3,-4096
- sub r16,zero,r2
- bgeu r3,r2,CLONE_OK
-
- /* store errno */
- call __errno_location
- stw r16,0(r2)
- movi r2,-1
-
-CLONE_OK:
- ldw ra,4(sp)
- ldw r16,0(sp)
- addi sp,sp,8
+
+ /* See if we're on the newly created thread. */
+ beq r2, zero, thread_start
+ /* Successful return from the parent */
ret
-.size clone,.-clone
+thread_start:
+ /* We expect the argument registers to be preserved across system
+ calls and across task cloning, so flags should be in r4 here. */
+ andi r2, r4, CLONE_VM
+ bne r2, zero, 2f
+ DO_CALL (getpid, 0)
+#ifdef RESET_PID
+ stw r2, PID_OFFSET(r23)
+ stw r2, TID_OFFSET(r23)
+#endif
+2:
+ ldw r5, 4(sp) /* Function pointer. */
+ ldw r4, 0(sp) /* Argument pointer. */
+ addi sp, sp, 8
+
+ /* Call the user's function. */
+ callr r5
+ /* _exit with the result. */
+ mov r4, r2
+#ifdef __PIC__
+ nextpc r22
+1: movhi r8, %hiadj(_gp_got - 1b)
+ addi r8, r8, %lo(_gp_got - 1b)
+ add r22, r22, r8
+ ldw r8, %call(HIDDEN_JUMPTARGET(_exit))(r22)
+ jmp r8
+#else
+ jmpi _exit
#endif
+
+END(__clone)
+libc_hidden_def (__clone)
+weak_alias (__clone, clone)