Chris Zankel writes:

The following patches add support for the Xtensa processor architecture
to uClibc. They are based on a recent SVN checkout (12/05/2007).

The first patch (attached to this post) adds Xtensa support to various
shared configuration and make files. The following patches then include
the Xtensa specific files and directories.

I welcome any feedback and would appreciate it if you could include the
patches into the mainline tree. I am certainly committed to maintain the port. 

Bob Wilson was kind enough to review the patches.

Some notes about the architecture: Xtensa is a configurable and
extensible processor architecture developed by Tensilica. For more
information, please visit: www.linux-xtensa.org.

1 files changed, 57 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/xtensa/mmap.S b/libc/sysdeps/linux/xtensa/mmap.S
new file mode 100644
index 000000000..c991e7d27
--- /dev/null
+++ b/libc/sysdeps/linux/xtensa/mmap.S
@@ -0,0 +1,57 @@
+/* Copyright (C) 2005, 2007 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., 51 Franklin Street - Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+#include "sysdep.h"
+#include <sys/syscall.h>
+
+#define PAGE_SHIFT 12
+
+/* __ptr_t __mmap (a2 = __ptr_t addr,
+		   a3 = size_t len,
+		   a4 = int prot,
+		   a5 = int flags,
+		   a6 = int fd,
+		   a7 = off_t offset) */
+
+ENTRY (__mmap)
+
+	/* We only support mmap2 in the kernel, so shift offset by
+	   page - size.  */
+	mov	a8, a6
+	mov	a6, a2
+	movi	a2, SYS_ify (mmap2)
+	srli	a9, a7, PAGE_SHIFT
+
+	/* syscall (a2 = NR_mmap2,
+		    a6 = arg0,
+		    a3 = arg1,
+		    a4 = arg2,
+		    a5 = arg3,
+		    a8 = arg4,
+		    a9 = arg5) */
+
+	syscall
+	bltz	a2, SYSCALL_ERROR_LABEL
+
+.Lpseudo_end:
+	retw
+
+PSEUDO_END (__mmap)
+
+weak_alias (__mmap, mmap)
+libc_hidden_weak (mmap)