add dockerfile for arm cross-compilation

docker/arm/Dockerfile

@@ -0,0 +1,69 @@
+FROM joshuawarner32/avian-build
+MAINTAINER Joshua Warner, joshuawarner32@gmail.com
+
+RUN dpkg --add-architecture armel && \
+    apt-get update && \
+    mkdir -p /opt/arm && \
+    apt-get download libc6-dev:armel \
+            linux-headers-3.13-1-all-armel:armel \
+            linux-libc-dev:armel \
+            libc6:armel \
+            zlib1g-dev:armel \
+            zlib1g:armel && \
+    for x in *.deb; do \
+        dpkg -x $x /opt/arm; \
+    done && \
+    rm *.deb && \
+    apt-get install -y \
+        wget \
+        libgmp-dev \
+        libmpfr-dev \
+        libmpc-dev \
+        libisl-dev && \
+    apt-get clean all && \
+    for x in $(find /opt/arm -type l); do \
+        r=$(readlink "$x" | sed 's,^/,/opt/arm/,g'); \
+        rm "$x"; \
+        ln -s "$r" "$x"; \
+    done
+
+RUN mkdir -p /var/src
+
+# Build & install binutils
+RUN wget ftp://sourceware.org/pub/binutils/snapshots/binutils-2.23.91.tar.bz2 -O /var/src/binutils.tar.bz2 && \
+    cd /var/src/ && tar -xjf binutils.tar.bz2 && rm binutils.tar.bz2 && \
+    cd /var/src/binutils* && \
+    mkdir build && \
+    cd build && \
+    ../configure \
+        --target=arm-linux-gnueabi \
+        --prefix=/opt/arm \
+        --disable-multilib \
+        --program-prefix=arm-linux-gnueabi- \
+        --with-sysroot=/opt/arm \
+        --with-headers=/opt/arm/usr/include && \
+    make && \
+    make install && \
+    cd /var/src && \
+    rm -rf *
+
+# build & install gcc
+RUN wget http://www.netgull.com/gcc/releases/gcc-4.8.2/gcc-4.8.2.tar.bz2 -O /var/src/gcc.tar.bz2 && \
+    cd /var/src/ && tar -xjf gcc.tar.bz2 && rm gcc.tar.bz2 && \
+    cd /var/src/gcc* && \
+    mkdir build && \
+    cd build && \
+    ../configure \
+        --target=arm-linux-gnueabi \
+        --enable-languages=c,c++ \
+        --prefix=/opt/arm \
+        --disable-multilib \
+        --program-prefix=arm-linux-gnueabi- \
+        --with-sysroot=/opt/arm \
+        --with-headers=/opt/arm/usr/include && \
+    make && \
+    make install && \
+    cd /var/src && \
+    rm -rf *
+
+ENV PATH $PATH:/opt/arm/bin