programs that are compiled with non-default regparm values are miscompiled if they use libgcc. This patch works around the problem for coreboot.
* drop libgcc from coreboot_apc.o, not needed. * wrap libgcc calls into regparm(0) variants so that coreboot can be compiled with other regparm values
Signed-off-by: Stefan Reinauer stepan@coresystems.de
Index: src/config/Config.lb =================================================================== --- src/config/Config.lb (revision 4675) +++ src/config/Config.lb (working copy) @@ -47,7 +47,7 @@
makerule coreboot_ram.o depends "src/arch/$(CONFIG_ARCH)/lib/c_start.o $(DRIVER) coreboot.a $(LIBGCC_FILE_NAME)" - action "$(CC) $(DISTRO_LFLAGS) -nostdlib -r -o $@ src/arch/$(CONFIG_ARCH)/lib/c_start.o $(DRIVER) -Wl,-( coreboot.a $(LIBGCC_FILE_NAME) -Wl,-)" + action "$(CC) $(DISTRO_LFLAGS) -nostdlib -r -o $@ src/arch/$(CONFIG_ARCH)/lib/c_start.o $(DRIVER) -Wl,--wrap,__divdi3 -Wl,--wrap,__udivdi3 -Wl,--wrap,__moddi3 -Wl,--wrap,__umoddi3 -Wl,-( coreboot.a $(LIBGCC_FILE_NAME) -Wl,-)" end
makerule coreboot_ram @@ -89,7 +89,7 @@ end
makerule coreboot_apc.o - depends "src/arch/$(CONFIG_ARCH)/lib/c_start.o coreboot_apc.a $(LIBGCC_FILE_NAME)" + depends "src/arch/$(CONFIG_ARCH)/lib/c_start.o coreboot_apc.a" action "$(CC) $(DISTRO_LFLAGS) -nostdlib -r -o $@ $^" end
Index: src/lib/Makefile.inc =================================================================== --- src/lib/Makefile.inc (revision 4675) +++ src/lib/Makefile.inc (working copy) @@ -12,6 +12,7 @@ obj-y += cbfs.o obj-y += lzma.o #obj-y += lzmadecode.o +obj-y += gcc.o
initobj-y += uart8250.o initobj-y += memset.o Index: src/lib/Config.lb =================================================================== --- src/lib/Config.lb (revision 4675) +++ src/lib/Config.lb (working copy) @@ -17,6 +17,8 @@ object fallback_boot.o object compute_ip_checksum.o object version.o +object gcc.o + # Force version.o to recompile every time makedefine .PHONY : version.o
Index: src/lib/gcc.c =================================================================== --- src/lib/gcc.c (revision 0) +++ src/lib/gcc.c (revision 0) @@ -0,0 +1,34 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2009 coresystems GmbH + * + * 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; version 2 of the License. + * + * This program 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; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA + */ + +/* GCC's libgcc handling is quite broken. While the libgcc functions + * are always regparm(0) the code that calls them uses whatever the + * compiler call specifies. Therefore we need a wrapper around those + * functions. + */ + +#define WRAP_LIBGCC_CALL(type, name) \ + type __real_##name(type a, type b) __attribute__((regparm(0))); \ + type __wrap_##name(type a, type b) { return __real_##name(a, b); } + +WRAP_LIBGCC_CALL(long long, __divdi3) +WRAP_LIBGCC_CALL(unsigned long long, __udivdi3) +WRAP_LIBGCC_CALL(long long, __moddi3) +WRAP_LIBGCC_CALL(unsigned long long, __umoddi3) +