Custom toolchain build fails

Question

I'm building an uClibc i486 cross toolchain for an embedded system. The toolchain is built on Debian Wheezy (x86-64) and consists of the following components:

• Binutils 2.24
• GCC 4.7.3
• Linux 3.2.54
• uClibc 0.9.33.2
• GMP 5.1.3
• MPFR 3.1.2
• MPC 1.0.2

These steps are used to build the toolchain:

Install Linux 3.2.54 headers

make mrproper
make \
    ARCH=x86 \
    INSTALL_HDR_PATH=/home/build-user/toolchain/i486-linux-uclibc \
    headers_install

This step is successfully completed.

Build Binutils 2.24

Binutils is built in a separate directory as specified in the documentation.

./configure \
    --prefix=/home/build-user/toolchain/ \
    --target=i486-linux-uclibc
    --with-sysroot=/home/build-user/toolchain/i486-linux-uclibc \
    --with-lib-path=/home/build-user/toolchain/i486-linux-uclibc/lib \
    --disable-nls \
    --disable-multilib

    make configure-host
    make
    make install

This step is successfully completed.

Build GMP 5.1.3

./configure \
    --prefix=/home/build-user/toolchain/gmp \
    --disable-shared \
    --enable-static

    make
    make install

This step is successfully completed.

Build MPFR 3.1.2

./configure \
    --prefix=/home/build-user/toolchain/mpfr \
    --with-gmp=/home/build-user/toolchain/gmp \
    --disable-shared \
    --enable-static

    make
    make install

This step is successfully completed.

Build MPC 1.0.2

./configure \
    --prefix=/home/build-user/toolchain/mpc \
    --with-gmp=/home/build-user/toolchain/gmp \
    --with-mpfr=/home/build-user/toolchain/mpfr \
    --disable-shared \
    --enable-static

    make
    make install

This step is successfully completed.

Build static GCC 4.7.3

GCC is built in a separate directory as specified in the documentation.

./configure \
    --prefix=/home/build-user/toolchain \
    --target=i486-linux-uclibc \
    --with-arch=i486 \
    --with-sysroot=/home/build-user/toolchain/i486-linux-uclibc \
    --disable-multiarch \
    --disable-nls \
    --disable-shared \
    --without-headers \
    --with-newlib \
    --disable-decimal-float \
    --disable-libgomp \
    --disable-libmudflap \
    --disable-libssp \
    --disable-libquadmath \
    --disable-threads \
    --enable-languages=c \
    --disable-multilib \
    --with-gmp=/home/build-user/toolchain/gmp \
    --with-mpfr=/home/build-user/toolchain/mpfr \
    --with-mpc=/home/build-user/toolchain/mpc

    make all-gcc all-target-libgcc
    make install-gcc install-target-libgcc

This step is successfully completed.

Build uClibc 0.9.33.2

The configuration file for uClibc is default with following options enabled:

TARGET_i386=y
CONFIG_486=y

UCLIBC_HAS_FENV=y
LINUXTHREADS_OLD=y

make \
    ARCH=x86 \
    DESTDIR=/home/build-user/toolchain/i486-linux-uclibc \
    CROSS=i486-linux-uclibc- \
    RUNTIME_PREFIX=/ \
    DEVEL_PREFIX=/ \
    KERNEL_HEADERS=/home/build-user/toolchain/i486-linux-uclibc/include \
    install

This step is successfully completed.

Build final GCC 4.7.3

GCC is built in a separate directory as specified in the documentation.

./configure \
    --prefix=/home/build-user/toolchain \
    --target=i486-linux-uclibc \
    --with-arch=i486 \
    --with-sysroot=/home/build-user/toolchain/i486-linux-uclibc \
    --with-native-system-header-dir=/include \
    --disable-multiarch \
    --disable-nls \
    --enable-libssp \
    --enable-c99 \
    --disable-libgomp \
    --enable-long-long \
    --disable-libmudflap \
    --enable-languages=c \
    --disable-multilib \
    --with-gmp=/home/build-user/toolchain/gmp \
    --with-mpfr=/home/build-user/toolchain/mpfr \
    --with-mpc=/home/build-user/toolchain/mpc

    make

This step fails with the following errors:

/bin/bash /home/build-user/toolchain/packages/gcc-4.7.3/libgcc/../mkinstalldirs .
/home/build-user/toolchain/gcc-final-build/./gcc/xgcc -B/home/build-user/toolchain/gcc-final-build/./gcc/ -B/home/build-user/toolchain/i486-linux-uclibc/bin/ -B/home/build-user/toolchain/i486-linux-uclibc/lib/ -isystem /home/build-user/toolchain/i486-linux-uclibc/include -isystem /home/build-user/toolchain/i486-linux-uclibc/sys-include -O2 -g -O2 -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE  -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition  -isystem ./include   -fpic -g -DIN_LIBGCC2 -fbuilding-libgcc -fno-stack-protector -shared -nodefaultlibs -Wl,--soname=libgcc_s.so.1 -Wl,--version-script=libgcc.map -o ./libgcc_s.so.1.tmp -g -O2 -B./ _muldi3_s.o _negdi2_s.o _lshrdi3_s.o _ashldi3_s.o _ashrdi3_s.o _cmpdi2_s.o _ucmpdi2_s.o _clear_cache_s.o _trampoline_s.o __main_s.o _absvsi2_s.o _absvdi2_s.o _addvsi3_s.o _addvdi3_s.o _subvsi3_s.o _subvdi3_s.o _mulvsi3_s.o _mulvdi3_s.o _negvsi2_s.o _negvdi2_s.o _ctors_s.o _ffssi2_s.o _ffsdi2_s.o _clz_s.o _clzsi2_s.o _clzdi2_s.o _ctzsi2_s.o _ctzdi2_s.o _popcount_tab_s.o _popcountsi2_s.o _popcountdi2_s.o _paritysi2_s.o _paritydi2_s.o _powisf2_s.o _powidf2_s.o _powixf2_s.o _powitf2_s.o _mulsc3_s.o _muldc3_s.o _mulxc3_s.o _multc3_s.o _divsc3_s.o _divdc3_s.o _divxc3_s.o _divtc3_s.o _bswapsi2_s.o _bswapdi2_s.o _clrsbsi2_s.o _clrsbdi2_s.o _fixunssfsi_s.o _fixunsdfsi_s.o _fixunsxfsi_s.o _fixsfdi_s.o _fixdfdi_s.o _fixxfdi_s.o _fixunssfdi_s.o _fixunsdfdi_s.o _fixunsxfdi_s.o _floatdisf_s.o _floatdidf_s.o _floatdixf_s.o _floatundisf_s.o _floatundidf_s.o _floatundixf_s.o _divdi3_s.o _moddi3_s.o _udivdi3_s.o _umoddi3_s.o _udiv_w_sdiv_s.o _udivmoddi4_s.o tf-signs_s.o addtf3_s.o divtf3_s.o eqtf2_s.o getf2_s.o letf2_s.o multf3_s.o negtf2_s.o subtf3_s.o unordtf2_s.o fixtfsi_s.o fixunstfsi_s.o floatsitf_s.o floatunsitf_s.o fixtfdi_s.o fixunstfdi_s.o floatditf_s.o floatunditf_s.o extendsftf2_s.o extenddftf2_s.o extendxftf2_s.o trunctfsf2_s.o trunctfdf2_s.o trunctfxf2_s.o enable-execute-stack_s.o unwind-dw2_s.o unwind-dw2-fde-dip_s.o unwind-sjlj_s.o unwind-c_s.o emutls_s.o libgcc.a -lc && rm -f ./libgcc_s.so && if [ -f ./libgcc_s.so.1 ]; then mv -f ./libgcc_s.so.1 ./libgcc_s.so.1.backup; else true; fi && mv ./libgcc_s.so.1.tmp ./libgcc_s.so.1 && ln -s libgcc_s.so.1 ./libgcc_s.so
/home/build-user/toolchain/i486-linux-uclibc/bin/ld: cannot find /lib/libc.so.0
/home/build-user/toolchain/i486-linux-uclibc/bin/ld: cannot find /lib/uclibc_nonshared.a
/home/build-user/toolchain/i486-linux-uclibc/bin/ld: cannot find /lib/ld-uClibc.so.0
collect2: error: ld returned 1 exit status
make[2]: *** [libgcc_s.so] Error 1
make[2]: Leaving directory `/home/build-user/toolchain/gcc-final-build/i486-linux-uclibc/libgcc'
make[1]: *** [all-target-libgcc] Error 2
make[1]: Leaving directory `/home/build-user/toolchain/gcc-final-build'
make: *** [all] Error 2

I check the linker search path:

/home/build-user/toolchain/i486-linux-uclibc/bin/ld --verbose | grep SEARCH_DIR

SEARCH_DIR("/home/build-user/toolchain/i486-linux-uclibc/lib");

The path is correct, so I search for the allegedly missing files in the directory:

find /home/build-user/toolchain/i486-linux-uclibc/lib \( -name libc.so.0 -o -name uclibc_nonshared.a -o -name ld-uClibc.so.0 \)

/home/build-user/toolchain/i486-linux-uclibc/lib/uclibc_nonshared.a
/home/build-user/toolchain/i486-linux-uclibc/lib/ld-uClibc.so.0
/home/build-user/toolchain/i486-linux-uclibc/lib/libc.so.0

All the files are found in the directory.

Can someone tell me what I'm doing wrong?

Answer 1

This is a guess, but when I build GCC cross compilers, I use sysroot equal to prefix. This creates a special configuration for binutils and GCC which may help you here.

Answer 2

I've had a similar problem lately.

I've used: uClibc-ng-1.0.29, GCC-6.2.0, Linux from Analog Devices (4.6.0 or something close to it) and binutils-2.27. It was a cross-build for ARM. But I think it should also work in this case.

The problem is that when building uClibc, libc.so is not a real binary but a linker script that contains locations of libc.so.1, uclibc_nonshared.a and ld-uClibc.so.1. When uClibc is built the way you did, the linker script (libc.so) provides locations of these libraries with respect to /.

The solutions is to build uClibc like this:

D=home/build-user/toolchain/i486-linux-uclibc;
make \
    ARCH=x86 \
    DESTDIR=/ \
    CROSS=i486-linux-uclibc- \
    RUNTIME_PREFIX=${D}/ \
    DEVEL_PREFIX=${D}/usr/ \
    KERNEL_HEADERS=/home/build-user/toolchain/i486-linux-uclibc/include \
    install

The eventual installation location remains the same, but the entrances in libc.so will contain now the correct paths to the missing/not-found libraries.

If you need for some reason RUNTIME_PREFIX to be the same as DEVEL_PREFIX then keep it. But uClibc's .config file suggests the way I proposed. Note that it may also affect building of GCC.