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Now it's time to replace second bootstrapping compiler with full-featured compiler tied to glibc and capable of building hosted code, not only freestanding code. Also new compiler will be independent from cygwin1.dll, unlike the old one.

1. Update C:\MinGW\msys\1.0\opt\crosstool\src\build_cross_toolchain.sh :

   #!/bin/bash
   export PATH=.:/usr/local/bin:/bin:/c/MinGW/bin
   export PATH=$PATH:/c/WINDOWS/system32:/c/WINDOWS
   export PATH=$PATH:/c/WINDOWS/System32/Wbem
   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 \
       --with-sysroot=$PREFIX \
       --disable-sjlj-exceptions --enable-checking=release \
       --enable-linker-build-id --enable-gnu-unique-object \
       --disable-nls --enable-languages=c,c++ \
       --with-headers --enable-shared --enable-threads=posix \
       --disable-multilib -enable-__cxa_atexit \
       --disable-fixed-point \
       --disable-libmudflap --disable-libssp \
       --disable-libgomp --without-ppl --without-cloog \
       --with-gmp --with-mpfr --with-mpc
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to configure gcc ==="
       exit 1
   fi
   make
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to make gcc ==="
       exit 1
   fi
   make install
   if [ "$?" -ne "0" ]; then
       echo "=== build script: failed to install gcc ==="
       exit 1
   fi
   
   echo "=== build script: OK ==="
   
   

2. Put C-style comments /* */ around "#define caddr_t char *" line in C:\MinGW\msys\1.0\opt\crosstool\src\gcc-4.9.2\gcc\configure to prevent the following error during build:

   In file included from ../../../gcc-4.9.2/libgcc/crtstuff.c:54:0:
   ../.././gcc/auto-host.h:1996:17: error: two or more data types in declaration specifiers
    #define caddr_t char *
                    ^
   In file included from ../../../gcc-4.9.2/libgcc/../gcc/tsystem.h:90:0,
                    from ../../../gcc-4.9.2/libgcc/crtstuff.c:60:
   C:/MinGW/msys/1.0/opt/crosstool/gcc-4.9.2-glibc-2.19/arm-linux-gnueabihf/arm-linux-gnueabihf/include/sys/types.h:116:26: error: expected identifier or '(' before ';' token
    typedef __caddr_t caddr_t;
                             ^
   make[2]: *** [crtbegin.o] Error 1
   make[2]: Leaving directory `/opt/crosstool/src/build-gcc/arm-linux-gnueabihf/libgcc'
   make[1]: *** [all-target-libgcc] Error 2
   make[1]: Leaving directory `/opt/crosstool/src/build-gcc'
   make: *** [all] Error 2
   

3. Run C:\MinGW\msys\1.0\opt\crosstool\src\build_cross_toolchain.cmd and wait until it completes.
4. If there are no errors, shutdown the MinGW VM and make snapshot "SNAP-D".

Notes:

• There may be an error in $TARGET/usr/include/sys/types.h when building GCC (in the line "typedef __caddr_t caddr_t;"). Reason: you forgot to patch GCC configure script as described above.
• Multilib is a special feature of GCC to allow building 32-bit targets on x86_64 platform. It's useless on ARM.
• If you didn't specify --with-sysroot=$PREFIX configure option, you will get the following error during build:
  
  In file included from ../../../gcc-4.9.2/libgcc/../gcc/libgcc2.c:29:0:
  ../../../gcc-4.9.2/libgcc/../gcc/tsystem.h:87:19: fatal error: stdio.h: No such file or directory
  compilation terminated.
  make[2]: *** [_muldi3.o] Error 1
  make[2]: Leaving directory `/opt/crosstool/src/build-gcc/arm-linux-gnueabihf/libgcc'
  make[1]: *** [all-target-libgcc] Error 2
  make[1]: Leaving directory `/opt/crosstool/src/build-gcc'
  make: *** [all] Error 2
   
  Also you will get this error if you didn't merge $PREFIX/usr and $PREFIX/$TARGET folders during MinGW deployment phase (see previous page).
• If you didn't specify --disable-fixed-point configure option, you will get the following errors during build:

  C:\MinGW\msys\1.0\bin\make.exe: *** couldn't commit memory
  for cygwin heap, Win32 error 487
  make[1]: *** [all-target-libgcc] Error 1
  make[1]: Leaving directory `/opt/crosstool/src/build-gcc'
  make: *** [all] Error 2
  

  and
  

  xgcc.exe: error: CreateProcess: No such file or directory
  make[2]: *** [libgcc_s.so] Error 1
  make[2]: Leaving directory `/opt/crosstool/src/build-gcc/arm-linux-gnueabihf/libgcc'
  make[1]: *** [all-target-libgcc] Error 2
  make[1]: Leaving directory `/opt/crosstool/src/build-gcc'
  make: *** [all] Error 2
  

  First one is non-fatal (can be overcomed by re-running `make' command for a 3-4 times), second one is related to exceeding Win32 command line length limit and can't be trivially avoided.

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:\MinGW\msys\1.0\opt\crosstool\src\build_cross_toolchain.cmd and wait until it completes.
5. If there are no errors, shutdown the MinGW VM and make snapshot "SNAP-E".

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