Building Glibc in the Cygwin VM

  1. Before building glibc, you must remove the following folders:
    /opt/crosstool/gcc-8.3.0-glibc-2.28/arm-linux-gnueabihf/include
/opt/crosstool/gcc-8.3.0-glibc-2.28/arm-linux-gnueabi/include
  2. Update C:\Cygwin\opt\crosstool\src\build_cross_toolchain.sh :
    #!/bin/bash
export TARGET=arm-linux-gnueabihf
export PREFIX=/opt/crosstool/gcc-8.3.0-glibc-2.28/$TARGET
export PATH=$PATH:$PREFIX/bin

cd /opt/crosstool/src/build-glibc
find . -delete
../glibc-2.28/configure --prefix=/usr \
    --with-headers=$PREFIX/usr/include \
    --enable-add-ons=nptl --enable-kernel=5.0.0 \
    --with-binutils=$PREFIX --build=x86_64-pc-cygwin \
    --host=$TARGET --enable-shared --disable-profile \
    --with-tls --with-__thread --without-gd --without-cvs \
    --enable-add-ons \
    libc_cv_forced_unwind=yes libc_cv_c_cleanup=yes libc_cv_ssp=no
if [ "$?" -ne "0" ]; then
    echo "=== build script: failed to configure glibc ==="
    exit 1
fi
make
if [ "$?" -ne "0" ]; then
    echo "=== build script: failed to make glibc ==="
    exit 1
fi
make install_root=$PREFIX install
if [ "$?" -ne "0" ]; then
    echo "=== build script: failed to install glibc ==="
    exit 1
fi

echo "=== build script: OK ==="
  3. Run C:\Cygwin\opt\crosstool\src\build_cross_toolchain.cmd and wait until it completes.
  4. If there are no errors, shutdown Cygwin VM and make snapshot "SNAP-9".
  5. Replace TARGET=arm-linux-gnueabihf with TARGET=arm-linux-gnueabi in C:\Cygwin\opt\crosstool\src\build_cross_toolchain.sh, then run C:\Cygwin\opt\crosstool\src\build_cross_toolchain.cmd and wait until it completes.
  6. If there are no errors, shutdown Cygwin VM and make snapshot "SNAP-10".

Notes:

  • Glibc build will take a lot of time, 4-5 times more than binutils + gcc.
  • "--enable-kernel" sets minimum version of Linux kernel for this glibc to run on. 5.0.0 should be good for Raspberry Pi OS 10 "Buster" running on Raspberry Pi 4.
  • "--prefix=/usr" is not dangerous and will not hurt your /usr in host system, unless you call "make install" in plain and wrong way. This is an old glibc joke.
  • If you get the following error messages during build:
    In file included from ../sysdeps/unix/sysv/linux/i386/sysdep.h:27,
                     from <stdin>:1:
    ../sysdeps/i386/nptl/tls.h:24:11: fatal error: stdbool.h: No such file or directory
     # include <stdbool.h>
               ^~~~~~~~~~~
    compilation terminated.
    make[2]: *** [../Makerules:287: /opt/crosstool/src/build-glibc/tcb-offsets.h] Error 1
    make[2]: Leaving directory '/opt/crosstool/src/glibc-2.28/csu'
    make[1]: *** [Makefile:258: csu/subdir_lib] Error 2
    make[1]: Leaving directory '/opt/crosstool/src/glibc-2.28'
    make: *** [Makefile:9: all] Error 2

    then you forgot to delete the following folders before running the script:
    /opt/crosstool/gcc-8.3.0-glibc-2.28/arm-linux-gnueabihf/include
/opt/crosstool/gcc-8.3.0-glibc-2.28/arm-linux-gnueabi/include
  • Also you may get error message about various missing syscalls (__-prefixed) if you forgot to replace .oS with .oZ in makefiles (Cygwin case-insensitive filesystem).


    • >> Read next section or buy already prepared cross-compiler (€10) to save your time.