MIPS support for libc.

Change-Id: I2864dea04b3faf2d919165dcaa600af5b16c41c8
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Raghu Gandham <raghu@mips.com>
diff --git a/libc/arch-mips/bionic/clone.S b/libc/arch-mips/bionic/clone.S
new file mode 100644
index 0000000..30fef8d
--- /dev/null
+++ b/libc/arch-mips/bionic/clone.S
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#include <linux/sched.h>
+#include <sys/linux-syscalls.h>
+#include <linux/errno.h>
+        
+	.text
+	.type __pthread_clone, @function
+	.global __pthread_clone
+	.align 4
+        .ent __pthread_clone
+        
+/*
+ * int __pthread_clone(int (*fn)(void*), void *child_stack,
+ *			 int flags, void *arg);
+ */
+
+__pthread_clone:
+        .set	noreorder
+        .cpload $t9
+        .set	reorder
+
+	# set up child stack
+	subu	$a1,16
+	sw	$a0,0($a1)	# fn
+	sw	$a3,4($a1)	# arg
+#	sw	$a1+16,8($a1)	# tls
+
+	/*
+	 * int sys_clone(int flags, void *child_stack, int *parent_tidptr,
+	 *	 struct user_desc *newtls, int *child_tidptr);
+	 */
+
+	move	$a0,$a2		# flags
+#	move	$a1,$a1		# child_stack
+	move	$a2,$0		# parent_tidptr
+	move	$a3,$0		# user_desc
+	and	$a0,~(CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)
+				# make sure the kernel doesn't access child_tidptr
+
+        li	$v0,__NR_clone
+        syscall
+
+        bnez	$a3,.L__error
+
+        beqz	$v0,.L__thread_start
+        
+        j $ra
+
+.L__thread_start:
+        lw	$a0,0($sp)	#  fn
+        lw	$a1,4($sp)	#  arg
+        addu	$a2,$sp,16	#  tls
+
+	# void __thread_entry(int (*func)(void*), void *arg, void *tls)
+        la	$t9, __thread_entry
+        j	$t9
+
+.L__error:
+	move	$a0,$v0
+	la	$t9,__set_errno
+	j	$t9
+
+        .end __pthread_clone
+
+
+    #
+    # This function is defined as:
+    #
+    #   pid_t  __bionic_clone( int  flags, void *child_stack,
+    #                          pid_t *pid, void *tls, pid_t *ctid,
+    #                          int  (*fn)(void *), void* arg );
+    #
+    # NOTE: This is not the same signature than the GLibc
+    #       __clone function here !! Placing 'fn' and 'arg'
+    #       at the end of the parameter list makes the
+    #       implementation much simpler.
+    #
+	.text
+	.type __bionic_clone, @function
+	.global __bionic_clone
+	.align 4
+        .ent __bionic_clone
+__bionic_clone:
+        .set	noreorder
+        .cpload $t9
+        .set	reorder
+
+	# set up child stack
+	subu	$a1,16
+	lw	$t0,20($sp)     # fn
+	lw	$t1,24($sp)     # arg
+	sw	$t0,0($a1)	# fn
+	sw	$t1,4($a1)	# arg
+
+	# remainder of arguments are correct for clone system call
+        li	$v0,__NR_clone
+        syscall
+
+        bnez	$a3,.L__error_bc
+
+        beqz	$v0,.L__thread_start_bc
+        
+        j $ra
+
+.L__thread_start_bc:
+        lw	$a0,0($sp)	#  fn
+        lw	$a1,4($sp)	#  arg
+
+	# void __bionic_clone_entry(int (*func)(void*), void *arg)
+        la	$t9,__bionic_clone_entry
+        j	$t9
+
+.L__error_bc:
+	move	$a0,$v0
+	la	$t9,__set_errno
+	j	$t9
+
+        .end __bionic_clone
+