ARM: Use local versions of libgcc functions instead of linking against libgcc.

The flags used to compile libgcc may make it incompatible with the code it's
linked against, and/or the hardware it's going to run on. Rather than try to
tease the right libgcc from the compiler, lets just leave it out and use our
own implementations of the necessary functions.

Most of these implementations were taken from the Linux kernel, except for
uldivmod.S which was taken from a CL originally written for U-Boot by
Che-Liang Chiou in December of 2010. It was modified to not use the CLZ
instruction on machines that don't have it, anything earlier than ARMv5. The
top block was taken from an earlier version of the same CL which didn't use
CLZ in that spot. The later block was written from scratch.

BUG=None
TEST=Built and booted into the bootblock on nyan. Ran a series of tests which
divided and modded a 64 bit value by various 32 bit values which were powers
of 2. Confirmed that this function was used and that the returned value was
correct. Printed decimal and hex versions of some values and verified that
they equaled each other. Built and booted on pit with serial enabled.
BRANCH=None

Original-Change-Id: I7527e28af411b7aa7f94579be95a6b352a91a224
Original-Signed-off-by: Gabe Black <gabeblack@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/172401
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Original-Commit-Queue: Gabe Black <gabeblack@chromium.org>
Original-Tested-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit be8c7a8f3292a7d7651b7c6dafc9a2c53afbd402)

*** This second patch is cherry-picked and squashed again to
*** pick up the libgcc changes that were skipped previously.

arm: Move libgcc assembly macros to arch/asm.h

libgcc/macros.h contains some useful assembly macros that are common in
Linux kernel code and facilitate things such as unified ARM/THUMB
assembly. This patch moves it to a more general place where it can be
used by other code as well.

BUG=None
TEST=Snow still boots.

Original-Change-Id: If68e8930aaafa706c54cf9a156fac826b31bb193
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/182178
Original-Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
(cherry picked from commit a780670def94a969829811fa8cf257f12b88f085)

*** Additional changes for stage specific builds

Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Change-Id: Ie3e48f34ebf6fbe20c3dd76ecbcbea7844e9466e
Reviewed-on: http://review.coreboot.org/7322
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 130 insertions, 0 deletions

diff --git a/src/arch/arm/libgcc/bpabi_asm.S b/src/arch/arm/libgcc/bpabi_asm.S
new file mode 100644
index 0000000000..27b4a1cfe8
--- /dev/null
+++ b/src/arch/arm/libgcc/bpabi_asm.S
@@ -0,0 +1,130 @@
+/* Miscellaneous BPABI functions.
+
+   Copyright (C) 2003, 2004, 2007, 2008  Free Software Foundation, Inc.
+   Contributed by CodeSourcery, LLC.
+
+   This file is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by the
+   Free Software Foundation; either version 2, or (at your option) any
+   later version.
+
+   In addition to the permissions in the GNU General Public License, the
+   Free Software Foundation gives you unlimited permission to link the
+   compiled version of this file into combinations with other programs,
+   and to distribute those combinations without any restriction coming
+   from the use of this file.  (The General Public License restrictions
+   do apply in other respects; for example, they cover modification of
+   the file, and distribution when not linked into a combine
+   executable.)
+
+   This file 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
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; see the file COPYING.  If not, write to
+   the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+
+#include <arch/asm.h>
+
+#ifdef __ARMEB__
+#define xxh r0
+#define xxl r1
+#define yyh r2
+#define yyl r3
+#else
+#define xxh r1
+#define xxl r0
+#define yyh r3
+#define yyl r2
+#endif
+
+#if defined __thumb2__
+
+.macro do_it cond
+	it	\cond
+.endm
+#define do_push push
+#define do_pop pop
+
+#else
+
+.macro do_it cond
+.endm
+#define do_push stmfd sp!,
+#define do_pop ldmfd sp!,
+
+#endif
+
+ENTRY(__aeabi_lcmp)
+
+	cmp	xxh, yyh
+	do_it	lt
+	movlt	r0, #-1
+	do_it	gt
+	movgt	r0, #1
+	do_it	ne
+	movne	pc, lr
+	subs	r0, xxl, yyl
+	do_it	lo
+	movlo	r0, #-1
+	do_it	hi
+	movhi	r0, #1
+	mov	pc, lr
+
+ENDPROC(__aeabi_lcmp)
+
+ENTRY(__aeabi_ulcmp)
+
+	cmp	xxh, yyh
+	do_it	lo
+	movlo	r0, #-1
+	do_it	hi
+	movhi	r0, #1
+	do_it	ne
+	movne	pc, lr
+	cmp	xxl, yyl
+	do_it	lo
+	movlo	r0, #-1
+	do_it	hi
+	movhi	r0, #1
+	do_it	eq
+	moveq	r0, #0
+	mov	pc, lr
+
+ENDPROC(__aeabi_ulcmp)
+
+ENTRY(__aeabi_ldivmod)
+	sub sp, sp, #8
+#if defined(__thumb2__)
+	mov ip, sp
+	push {ip, lr}
+#else
+	do_push {sp, lr}
+#endif
+	bl __gnu_ldivmod_helper
+	ldr lr, [sp, #4]
+	add sp, sp, #8
+	do_pop {r2, r3}
+	mov	pc, lr
+
+ENDPROC(__aeabi_ldivmod)
+
+ENTRY(__aeabi_uldivmod)
+	sub sp, sp, #8
+#if defined(__thumb2__)
+	mov ip, sp
+	push {ip, lr}
+#else
+	do_push {sp, lr}
+#endif
+	bl __gnu_uldivmod_helper
+	ldr lr, [sp, #4]
+	add sp, sp, #8
+	do_pop {r2, r3}
+	mov	pc, lr
+
+ENDPROC(__aeabi_uldivmod)