Alexandre Oliva writes:

This patch adds code to uClibc to support a new ABI designed for the
FR-V architecture, that enables text segments of executables and
shared libraries to be shared by multiple processes on an OS such as
uClinux, that can run on FR-V processors without an MMU.

Patches for binutils and GCC have just been posted in the
corresponding mailing lists.  The binutils patch was approved,
but there's one additional patch pending review, that I posted
this week.  An updated GCC patch will be posted to
gcc-patches@gcc.gnu.org as soon as I complete testing (I used a
known-good compiler to test the uClibc patch below).

Since the existing dynamic loader code didn't support independent
relocation of segments, it required changes that were somewhat
extensive.  I've added a number of new machine-specific macros to try
to keep the platform and ABI-specific details outside the generic
code.  I hope this is not a problem.

1 files changed, 71 insertions, 0 deletions

diff --git a/ldso/ldso/frv/resolve.S b/ldso/ldso/frv/resolve.S
new file mode 100644
index 000000000..d9706c746
--- /dev/null
+++ b/ldso/ldso/frv/resolve.S
@@ -0,0 +1,71 @@
+     /* Copyright (C) 2003 Red Hat, Inc.
+	Contributed by Alexandre Oliva <aoliva@redhat.com>
+
+This file is part of uClibc.
+
+uClibc 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.
+
+uClibc 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 Lesser General Public
+License along with uClibc; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
+USA.  */
+	
+     /* The function below is tail-called by resolver stubs when a
+	lazily-bound function is called.  It must preserve all
+	registers that could be used to pass arguments to the actual
+	function.  Upon _dl_linux_resolve entry, GR14 holds the
+	address of a lazy PLT entry, so @(GR14,-4) is the lazy
+	relocation number that we have to pass to _dl_linux_resolver.
+	GR15 holds the caller's GOT, from which we extract the
+	elf_resolve* that _dl_linux_resolver needs as well.
+
+	_dl_linux_resolver() figures out where the jump symbol is
+	_really_ supposed to have jumped to and returns that to us.
+	Once we have that, we prepare to tail-call the actual
+	function, clean up after ourselves, restoring the original
+	arguments, then jump to the fixed up address.  */
+
+	.text
+	.p2align 4
+
+	.hidden	_dl_linux_resolve
+	.global	_dl_linux_resolve
+	.type	_dl_linux_resolve,@function
+
+_dl_linux_resolve:
+	/* Preserve arguments.  */
+	addi	sp, -8*4, sp
+	stdi	gr8, @(sp, 8)
+	stdi	gr10, @(sp, 16)
+	stdi	gr12, @(sp, 24)
+	movsg	lr,gr8
+	st	gr8, @(sp,gr0)
+
+	/* Prepare to call _dl_linux_resolver.  */
+	ldi	@(gr15, 8), gr8
+	ldi	@(gr14, -4), gr9
+	mov.p	gr5, gr15
+	call	_dl_linux_resolver
+	
+	/* Move aside return value that contains the FUNCDESC_VALUE.  */
+	ldd	@(gr8,gr0),gr14
+
+	/* Restore arguments.  */
+	ld	@(sp, gr0), gr8
+	movgs	gr8,lr
+	lddi	@(sp, 24), gr12
+	lddi	@(sp, 16), gr10
+	lddi	@(sp, 8), gr8
+	addi	sp, 8*4, sp
+
+	/* Now jump to the actual function.  */
+	jmpl	@(gr14, gr0)
+	.size	_dl_linux_resolve, . - _dl_linux_resolve