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1. Update C:\Cygwin\opt\crosstool\src\build_cross_toolchain.sh :

   #!/bin/bash
   
   export TARGET=arm-linux-gnueabihf
   export PREFIX=/opt/crosstool/gcc-4.9.2-glibc-2.19/$TARGET
   
   cd /opt/crosstool/src/build-binutils
   find . -delete
   ../binutils-2.25/configure --target=$TARGET \
       --prefix=$PREFIX --with-sysroot=$TARGET \
       --disable-nls --with-arch=armv6
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to configure binutils ==="
       exit 1
   fi
   make all
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to make binutils ==="
       exit 1
   fi
   make install
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to install binutils ==="
       exit 1
   fi
   
   
   export PATH=$PATH:$PREFIX/bin
   cd /opt/crosstool/src/build-gcc
   find . -delete
   ../gcc-4.9.2/configure --target=$TARGET --prefix=$PREFIX \
       --with-arch=armv6 --with-fpu=vfp --with-float=hard \
       --disable-sjlj-exceptions --enable-checking=release \
       --enable-linker-build-id --enable-gnu-unique-object \
       --disable-nls --enable-languages=c \
       --without-headers --disable-shared --disable-threads \
       --disable-multilib --disable-decimal-float \
       --disable-libmudflap --disable-libssp \
       --disable-libgomp --without-ppl --without-cloog \
       --with-gmp --with-mpfr --with-mpc
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to configure gcc ==="
       exit 1
   fi
   make all-gcc
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to make gcc ==="
       exit 1
   fi
   make install-gcc
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to install gcc ==="
       exit 1
   fi
   make all-target-libgcc
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to make libgcc ==="
       exit 1
   fi
   make install-target-libgcc
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to install libgcc ==="
       exit 1
   fi
   
   echo "=== build script: OK ==="
   

2. Run C:\Cygwin\opt\crosstool\src\build_cross_toolchain.cmd and wait until it completes.
3. If there are no errors, shutdown the Cygwin VM and make snapshot "SNAP-4".

Notes:

• If there's complaint about missing file fenv.h, then you forgot to specify "--disable-decimal-float" when configuring gcc.
• "--without-headers" means freestanding-mode only compiler without libc dependency.
• Multilib is a special feature of GCC to allow building 32-bit targets on x86_64 platform. It's useless on ARM.

Additional steps to support SoftFP ABI:

1. Replace TARGET=arm-linux-gnueabihf with TARGET=arm-linux-gnueabi in build_cross_toolchain.sh
2. binutils configure flags: --with-arch=armv4t
3. gcc configure flags: --with-arch=armv4t --with-float=soft. Also remove --with-fpu=vfp.
4. Run C:\Cygwin\opt\crosstool\src\build_cross_toolchain.cmd and wait until it completes.
5. If there are no errors, shutdown the Cygwin VM and make snapshot "SNAP-5".

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