need help with gcc 4.1.0 crosscompiler for arm

marty fouts
Wed Apr 12 23:11:00 GMT 2006

I'm obviously doing something stupid, and would appreciate some help.

I've got an embedded application running on arm hardware. Currently it
is built with gcc 3.4.3 and binutils 2.15.  I configure binutils and
gcc in the obvious ways:

../binutils-2.15/configure --prefix=/usr/local/armdev-3.4.3 --target=arm-elf

../gcc-3.4.3/configure --prefix=/usr/local/armdev-3.4.3
--target=arm-elf --enable-languages=c,c++

after having patched gcc/config/arm/t-elf using this patch file:

-----     patch file     -----
--- gcc-3.4.2/gcc/config/arm/t-arm-elf  2003-09-30 03:21:41.000000000 -0700
+++ gcc-3.4.2-p/gcc/config/arm/t-arm-elf        2004-09-17
09:29:58.312527908 -0700
@@ -26,9 +26,9 @@
 # MULTILIB_DIRNAMES   += 32bit 26bit
 # MULTILIB_EXCEPTIONS += *mthumb/*mapcs-26*
-# MULTILIB_OPTIONS    += mno-thumb-interwork/mthumb-interwork
-# MULTILIB_DIRNAMES   += normal interwork
-# MULTILIB_EXCEPTIONS += *mapcs-26/*mthumb-interwork*
+MULTILIB_OPTIONS    += mno-thumb-interwork/mthumb-interwork
+MULTILIB_DIRNAMES   += normal interwork
+MULTILIB_EXCEPTIONS += *mapcs-26/*mthumb-interwork*
 # MULTILIB_OPTIONS    += fno-leading-underscore/fleading-underscore
 # MULTILIB_DIRNAMES   += elf under
@@ -71,7 +71,7 @@
 # Currently there is a bug somewhere in GCC's alias analysis
 # or scheduling code that is breaking _fpmul_parts in fp-bit.c.
 # Disabling function inlining is a workaround for this problem.
-TARGET_LIBGCC2_CFLAGS = -Dinhibit_libc -fno-inline
+TARGET_LIBGCC2_CFLAGS = -Dinhibit_libc -fno-inline -msoft-float

 # Assemble startup files.
 $(T)crti.o: $(srcdir)/config/arm/crti.asm $(GCC_PASSES)

-----     end of patch file     -----

GCC builds fine and builds the application fine.

I try doing the same thing for gcc 4.1.0 and gcc builds fine, but when
it finally gets around to trying to link the executable, I get error
messages that I *think* mean that libgcc is being built with arm
floating point instructions, for instance:

/usr/local/gnuarm-4.1.0/bin/arm-elf-ld: ERROR:
uses FPA instructions, whereas application.elf does not

I've tried every configuration option I can think of to build libgcc
without floating point, but have not managed to do so.

As I said, I'm obviously doing something dumb, and any help in
figuring out what I should do instead would be greatly appreciated.



More information about the Gcc-help mailing list