Hello,
i had some difficulties in using the GDB on the target. The first message was "Sorry Dave, i can't do that, unknown symbol format elf32-i386"
After some research i found the advice that the readelf.o object is missing, so the debugger isn't able to read the object file.
In the gdb/config.log i found the test "checking for ELF support in BFD" which fails because of an unresolved symbol to __lxstat in libiberty.
The base problem was the library include order: the gdb want's to link against it's own libiberty.a but the order is
<buildroot>/build_i386/staging_dir/lib
<buildroot>/build_i386/staging_dir/usr/lib
../bfd
../libiberty
so the libiberty.a from <buildroot>/build_i386/staging_dir/usr/lib is used which is linked against the libc of the host system.
After moving the local directories before the staging directories by modifying the <buildroot>/toolchain_build_i386/gdb-6.8/gdb/configure, the "checking for ELF support in BFD" was successful, the readelf.o was included and gdb works like a dream on the target.
Hope this helps someone, maybe the gdb developers can change the library order or the buildroot team can create a patch to do that.
