On Fri, Aug 16, 2013 at 09:26:51PM +0200, Sam Ravnborg wrote: > On Fri, Aug 16, 2013 at 08:43:35AM -0700, Guenter Roeck wrote: > > On 08/16/2013 02:45 AM, Max Filippov wrote: > >>>> Guenter, > >>>> can you share a complete build log with V=1? > >>>> > >>> > >>> http://roeck-us.net/linux/logs/make.xtensa.log.bad > >>> http://roeck-us.net/linux/logs/make.xtensa.log.ok > >>> > >>> Key difference: the failing command in the bad case is > >>> xtensa-linux-objcopy -O elf32-xtensa-le > >>> and in the good case > >>> xtensa-linux-objcopy -O elf32-xtensa-be > >>> > >>> Same compiler (4.6.3 from kernel.org), same configuration file, same > >>> command > >>> line. > >>> Configuration file is generated from defconfig, and the resulting .config > >>> file > >>> is the same in both cases. > >>> > >>> If I execute make and expicitly set BIG_ENDIAN=1 on the failing system as > >>> parameter to it, > >>> it works fine. If I set BIG_ENDIAN=0 on the passing system, it fails. > >>> > >>> I am puzzled. Guess there must be something different, but I have no idea > >>> what it might be. > >> > >> What is the output of > >> > >> echo -e __XTENSA_EB__ | xtensa-linux-gcc -E - > >> > >> on the failing system? > >> > > It is "1", but that let me pinpoint the problem. > > > > On the failing system, the version of echo executed by make does > > not understand the "-e" option. Thus, when running > > arch/xtensa/boot/Makefile, > > "echo -e __XTENSA_EB__" returns "-e __XTENSA_EB__", which doesn't compile, > > and BIG_ENDIAN ends up being 0. So the compiler is completely innocent. > > > > I found out the root source: SHELL is set the /bin/sh, which on the failing > > system points to /bin/dash (default in Ubuntu, or at least it used to be). > > dash apparently has a built-in version of echo which does not understand > > '-e'. > > Could you try to replace "echo -e bla" with "printf "bla". > Kbuild.include uses some similar tricks but here printf is used. > Maybe this can be dash compatible then > "echo" would do perfectly fine in this case. Besides, there are more "echo -e" in arch/xtensa/Makefile. Those only cause unpredictable build results (because neither big endian not little endian is set because of it), but no errors.
Problem is that "echo -e" is used elsewhere in various kernel makefiles, not just for xtensa. Those don't cause odd errors like the one I observed, but may result in unpredictable behavior. I am not sure if I should try to fix that. Maybe we should just put "don't try to compile the linux kernel with dash as default shell" as a note somewhere. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
