[PATCH] kexec/powerpc fix optimization for size (gcc -Os) build

Maxim Uvarov muvarov at gmail.com
Thu Sep 30 11:52:16 EDT 2010 

    crt.S patch had fixes for gcc -Os (optimaze for size), same as
    kernel has. Without this fixes powerpc gcc 4.4 generates forever
    loop functions for kexec.

    This happends because crtsavres code was spit up to individual files
    (http://gcc.gnu.org/ml/gcc-patches/2008-03/msg01294.html) and
    kexec purgatory code has following options:
    --no-undefined -nostartfiles -nostdlib -nodefaultlibs
    So in that case crtasaveregs function are not defined and final object
    file has been linked without them.  This does not happen with applications
    built without -nostdlib, because gcc will add it's standard functions.
Signed-off-by: Maxim Uvarov <muvarov at gmail.com>
---

 purgatory/arch/ppc/misc.S |  229 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 229 insertions(+), 0 deletions(-)

diff --git a/purgatory/arch/ppc/misc.S b/purgatory/arch/ppc/misc.S
index b0a5486..bc6a18d 100644
--- a/purgatory/arch/ppc/misc.S
+++ b/purgatory/arch/ppc/misc.S
@@ -16,6 +16,235 @@
 
 #include "ppc_asm.h"	
 
+/* 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"
+
+#define _GLOBAL(name) \
+	.type name, at 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
+
 	.text
 
 /*


Best regards,
Maxim Uvarov.

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