grab a tiny mmap implementation from glibc

1 files changed, 49 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/i386/mmap.S b/libc/sysdeps/linux/i386/mmap.S
new file mode 100644
index 000000000..5dde939bf
--- /dev/null
+++ b/libc/sysdeps/linux/i386/mmap.S
@@ -0,0 +1,49 @@
+/* Copyright (C) 1995,96,97,98,99,2000,2002,2005 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#define _ERRNO_H	1
+#include <features.h>
+#include <bits/errno.h>
+#include <sys/syscall.h>
+
+.text
+.global mmap
+.type   mmap,%function
+mmap:
+
+	/* Save registers.  */
+	movl %ebx, %edx
+
+	movl $__NR_mmap, %eax	/* System call number in %eax.  */
+
+	lea 4(%esp), %ebx		/* Address of args is 1st arg.  */
+
+	/* Do the system call trap.  */
+	int $0x80
+
+	/* Restore registers.  */
+	movl %edx, %ebx
+
+	/* If 0 > %eax > -4096 there was an error.  */
+	cmpl $-4096, %eax
+	ja __syscall_error
+
+	/* Successful; return the syscall's value.  */
+	ret
+
+.size mmap,.-mmap