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+#
+# __mmap.S, part of the i960 support for the uClibc library.
+#
+# Copyright (C) 2002 by Okiok Data Ltd. http://www.okiok.com/
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU Library General Public License as published by the Free
+# Software Foundation; either version 2 of the License, or (at your option) any
+# later version.
+#
+# This program 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 Library General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Library General Public License
+# along with this program; if not, write to the Free Software Foundation, Inc.,
+# at 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+#
+# Derived from an old port of uC-libc to the i960 by Keith Adams (kma@cse.ogi.edu).
+#
+
+#include <sys/syscall.h>
+
+/* This is a plain system call. The 6 arguments are already set up correctly */
+/* void * mmap(void *start, size_t length, int prot , int flags, int fd, off_t offset) */
+
+
+ .globl _mmap
+_mmap:
+ mov g13, r3
+ ldconst __NR_mmap, g13
+ calls 0
+ mov r3, g13
+
+ /* We now need to check if the return value is a small negative integer. */
+ /* This is somewhat tricky as the return code (normally an address) is an */
+ /* unsigned type, or an ordinal in i960 assembler. */
+ /* We'll use the fact that, integers from -256 to -1 are ordinals 0xFFFFFF00 to 0xFFFFFFFF. */
+ /* So by checking that the return address is in the top range of the ordinals, we'll */
+ /* in fact be checking if it's not an encoded negated erro code. */
+
+ /* The range -256 to -1 should be enough since that in uClinux 2.0.39, there are */
+ /* 124 system calls for the i960. */
+
+ ldconst 0xFFFFFF00, r3 /* This is the integer's -256 representation */
+ cmpobl g0, r3, 1f /* Something smaller than this means it's out of the range, and a valid address */
+ subi g0, 0, r3 /* If it's an errno, save its negated (now positive) value in _errno. */
+ st r3, _errno
+ subi 1, 0, g0 /* And return -1. */
+1:
+ ret