powerpc new toolchains fix (crt.S)

Linker does not provide some vital functions when building freestanding
applications with a new toolchain, so we have to provide our own CRT.

p.s.
Without the CRT we won't see any build errors (since the purgatory is
linked with --no-undefined), but the purgatory code won't work,
'kexec -e' will just hang the board.

I added option to configure to keep code buildable for old toolchais.
But there should be way to do this automatically.

Author: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Maxim Uvarov <muvarov@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

2 files changed, 264 insertions, 0 deletions

diff --git a/purgatory/arch/ppc/Makefile b/purgatory/arch/ppc/Makefile
index 72289a09..4020778e 100644
--- a/purgatory/arch/ppc/Makefile
+++ b/purgatory/arch/ppc/Makefile
@@ -6,6 +6,7 @@ ppc_PURGATORY_SRCS += purgatory/arch/ppc/v2wrap_32.S
 ppc_PURGATORY_SRCS += purgatory/arch/ppc/misc.S
 ppc_PURGATORY_SRCS += purgatory/arch/ppc/purgatory-ppc.c
 ppc_PURGATORY_SRCS += purgatory/arch/ppc/console-ppc.c
+ppc_PURGATORY_SRCS += purgatory/arch/ppc/crt.S
 
 dist += purgatory/arch/ppc/Makefile $(ppc_PURGATORY_SRCS)		\
 	purgatory/arch/ppc/purgatory-ppc.h purgatory/arch/ppc/ppc_asm.h
diff --git a/purgatory/arch/ppc/crt.S b/purgatory/arch/ppc/crt.S
new file mode 100644
index 00000000..70f4d610
--- /dev/null
+++ b/purgatory/arch/ppc/crt.S
@@ -0,0 +1,263 @@
+/* This is from linux-2.6/arch/powerpc/lib/crtsavres.S:
+ *
+ * Special support for eabi and SVR4
+ *
+ *   Copyright (C) 1995, 1996, 1998, 2000, 2001 Free Software Foundation, Inc.
+ *   Copyright 2008 Freescale Semiconductor, Inc.
+ *   Written By Michael Meissner
+ *
+ * Based on gcc/config/rs6000/crtsavres.asm from gcc
+ *
+ * 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 with other programs, and to distribute
+ * those programs 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 another program.)
+ *
+ * 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.
+ *
+ *    As a special exception, if you link this library with files
+ *    compiled with GCC to produce an executable, this does not cause
+ *    the resulting executable to be covered by the GNU General Public License.
+ *    This exception does not however invalidate any other reasons why
+ *    the executable file might be covered by the GNU General Public License.
+ */
+#include "config.h"
+
+/* On PowerPC64 Linux, these functions are provided by the linker.  */
+#ifndef PPC_OLDTOOLCHAIN
+#ifndef __powerpc64__
+#define _GLOBAL(name) \
+	.type name,@function; \
+	.globl name; \
+name:
+
+/* Routines for saving integer registers, called by the compiler.  */
+/* Called with r11 pointing to the stack header word of the caller of the */
+/* function, just beyond the end of the integer save area.  */
+
+_GLOBAL(_savegpr_14)
+_GLOBAL(_save32gpr_14)
+	stw	14,-72(11)	/* save gp registers */
+_GLOBAL(_savegpr_15)
+_GLOBAL(_save32gpr_15)
+	stw	15,-68(11)
+_GLOBAL(_savegpr_16)
+_GLOBAL(_save32gpr_16)
+	stw	16,-64(11)
+_GLOBAL(_savegpr_17)
+_GLOBAL(_save32gpr_17)
+	stw	17,-60(11)
+_GLOBAL(_savegpr_18)
+_GLOBAL(_save32gpr_18)
+	stw	18,-56(11)
+_GLOBAL(_savegpr_19)
+_GLOBAL(_save32gpr_19)
+	stw	19,-52(11)
+_GLOBAL(_savegpr_20)
+_GLOBAL(_save32gpr_20)
+	stw	20,-48(11)
+_GLOBAL(_savegpr_21)
+_GLOBAL(_save32gpr_21)
+	stw	21,-44(11)
+_GLOBAL(_savegpr_22)
+_GLOBAL(_save32gpr_22)
+	stw	22,-40(11)
+_GLOBAL(_savegpr_23)
+_GLOBAL(_save32gpr_23)
+	stw	23,-36(11)
+_GLOBAL(_savegpr_24)
+_GLOBAL(_save32gpr_24)
+	stw	24,-32(11)
+_GLOBAL(_savegpr_25)
+_GLOBAL(_save32gpr_25)
+	stw	25,-28(11)
+_GLOBAL(_savegpr_26)
+_GLOBAL(_save32gpr_26)
+	stw	26,-24(11)
+_GLOBAL(_savegpr_27)
+_GLOBAL(_save32gpr_27)
+	stw	27,-20(11)
+_GLOBAL(_savegpr_28)
+_GLOBAL(_save32gpr_28)
+	stw	28,-16(11)
+_GLOBAL(_savegpr_29)
+_GLOBAL(_save32gpr_29)
+	stw	29,-12(11)
+_GLOBAL(_savegpr_30)
+_GLOBAL(_save32gpr_30)
+	stw	30,-8(11)
+_GLOBAL(_savegpr_31)
+_GLOBAL(_save32gpr_31)
+	stw	31,-4(11)
+	blr
+
+/* Routines for restoring integer registers, called by the compiler.  */
+/* Called with r11 pointing to the stack header word of the caller of the */
+/* function, just beyond the end of the integer restore area.  */
+
+_GLOBAL(_restgpr_14)
+_GLOBAL(_rest32gpr_14)
+	lwz	14,-72(11)	/* restore gp registers */
+_GLOBAL(_restgpr_15)
+_GLOBAL(_rest32gpr_15)
+	lwz	15,-68(11)
+_GLOBAL(_restgpr_16)
+_GLOBAL(_rest32gpr_16)
+	lwz	16,-64(11)
+_GLOBAL(_restgpr_17)
+_GLOBAL(_rest32gpr_17)
+	lwz	17,-60(11)
+_GLOBAL(_restgpr_18)
+_GLOBAL(_rest32gpr_18)
+	lwz	18,-56(11)
+_GLOBAL(_restgpr_19)
+_GLOBAL(_rest32gpr_19)
+	lwz	19,-52(11)
+_GLOBAL(_restgpr_20)
+_GLOBAL(_rest32gpr_20)
+	lwz	20,-48(11)
+_GLOBAL(_restgpr_21)
+_GLOBAL(_rest32gpr_21)
+	lwz	21,-44(11)
+_GLOBAL(_restgpr_22)
+_GLOBAL(_rest32gpr_22)
+	lwz	22,-40(11)
+_GLOBAL(_restgpr_23)
+_GLOBAL(_rest32gpr_23)
+	lwz	23,-36(11)
+_GLOBAL(_restgpr_24)
+_GLOBAL(_rest32gpr_24)
+	lwz	24,-32(11)
+_GLOBAL(_restgpr_25)
+_GLOBAL(_rest32gpr_25)
+	lwz	25,-28(11)
+_GLOBAL(_restgpr_26)
+_GLOBAL(_rest32gpr_26)
+	lwz	26,-24(11)
+_GLOBAL(_restgpr_27)
+_GLOBAL(_rest32gpr_27)
+	lwz	27,-20(11)
+_GLOBAL(_restgpr_28)
+_GLOBAL(_rest32gpr_28)
+	lwz	28,-16(11)
+_GLOBAL(_restgpr_29)
+_GLOBAL(_rest32gpr_29)
+	lwz	29,-12(11)
+_GLOBAL(_restgpr_30)
+_GLOBAL(_rest32gpr_30)
+	lwz	30,-8(11)
+_GLOBAL(_restgpr_31)
+_GLOBAL(_rest32gpr_31)
+	lwz	31,-4(11)
+	blr
+
+/* Routines for restoring integer registers, called by the compiler.  */
+/* Called with r11 pointing to the stack header word of the caller of the */
+/* function, just beyond the end of the integer restore area.  */
+
+_GLOBAL(_restgpr_14_x)
+_GLOBAL(_rest32gpr_14_x)
+	lwz	14,-72(11)	/* restore gp registers */
+_GLOBAL(_restgpr_15_x)
+_GLOBAL(_rest32gpr_15_x)
+	lwz	15,-68(11)
+_GLOBAL(_restgpr_16_x)
+_GLOBAL(_rest32gpr_16_x)
+	lwz	16,-64(11)
+_GLOBAL(_restgpr_17_x)
+_GLOBAL(_rest32gpr_17_x)
+	lwz	17,-60(11)
+_GLOBAL(_restgpr_18_x)
+_GLOBAL(_rest32gpr_18_x)
+	lwz	18,-56(11)
+_GLOBAL(_restgpr_19_x)
+_GLOBAL(_rest32gpr_19_x)
+	lwz	19,-52(11)
+_GLOBAL(_restgpr_20_x)
+_GLOBAL(_rest32gpr_20_x)
+	lwz	20,-48(11)
+_GLOBAL(_restgpr_21_x)
+_GLOBAL(_rest32gpr_21_x)
+	lwz	21,-44(11)
+_GLOBAL(_restgpr_22_x)
+_GLOBAL(_rest32gpr_22_x)
+	lwz	22,-40(11)
+_GLOBAL(_restgpr_23_x)
+_GLOBAL(_rest32gpr_23_x)
+	lwz	23,-36(11)
+_GLOBAL(_restgpr_24_x)
+_GLOBAL(_rest32gpr_24_x)
+	lwz	24,-32(11)
+_GLOBAL(_restgpr_25_x)
+_GLOBAL(_rest32gpr_25_x)
+	lwz	25,-28(11)
+_GLOBAL(_restgpr_26_x)
+_GLOBAL(_rest32gpr_26_x)
+	lwz	26,-24(11)
+_GLOBAL(_restgpr_27_x)
+_GLOBAL(_rest32gpr_27_x)
+	lwz	27,-20(11)
+_GLOBAL(_restgpr_28_x)
+_GLOBAL(_rest32gpr_28_x)
+	lwz	28,-16(11)
+_GLOBAL(_restgpr_29_x)
+_GLOBAL(_rest32gpr_29_x)
+	lwz	29,-12(11)
+_GLOBAL(_restgpr_30_x)
+_GLOBAL(_rest32gpr_30_x)
+	lwz	30,-8(11)
+_GLOBAL(_restgpr_31_x)
+_GLOBAL(_rest32gpr_31_x)
+	lwz	0,4(11)
+	lwz	31,-4(11)
+	mtlr	0
+	mr	1,11
+	blr
+
+/* This is from linux-2.6/arch/powerpc/kernel/misc_32.S
+ * 
+ * This file contains miscellaneous low-level functions.
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
+ * and Paul Mackerras.
+ *
+ * kexec bits:
+ * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
+ * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
+ *
+ * This program 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 of the License, or (at your option) any later version.
+ *
+ */
+
+_GLOBAL(__lshrdi3)
+	subfic	6,5,32
+	srw	4,4,5	# LSW = count > 31 ? 0 : LSW >> count
+	addi	7,5,32	# could be xori, or addi with -32
+	slw	6,3,6	# t1 = count > 31 ? 0 : MSW << (32-count)
+	srw	7,3,7	# t2 = count < 32 ? 0 : MSW >> (count-32)
+	or	4,4,6	# LSW |= t1
+	srw	3,3,5	# MSW = MSW >> count
+	or	4,4,7	# LSW |= t2
+	blr
+#endif
+#endif