Cross toolchain EM7075

From Eminent Opensource

Installing the toolchain

For the EM7075 we have used the Sourcery toolchain. The lite version is available for those who wish to compile their own applications.

1. Download the toolchain from

wget http://www.codesourcery.com/sgpp/lite/mips/portal/package3548/public/mips-linux-gnu/mips-4.3-51-mips-linux-gnu.bin

1. Run the installation package. It is a self-installing binary file

chmod +x mips-4.3-51-mips-linux-gnu.bin
./mips-4.3-51-mips-linux-gnu.bin

1. Follow the steps on-screen and select a suitable folder to install.
2. We will be using /opt/Sourcery_G++_Lite in several examples, so it's best to install it there.
3. Follow the steps and confirmation prompts until the toolchain is installed.

Once the toolchain is installed, you are almost ready to build your first application.

Compiler flags

The EM7075 uses a powerfull 500mhz MIPS, Little Endian cpu. Since the toolchain can be configured for multiple targets, it's best to use a single 'build.sh' script and edit that to ensure correct CFLAGS and LDFLAGS are used. You will always need to use at least CFLAGS="-EL " to get the correct binary files..

Cross-Compilation script example: Zlib

Below example shows how to compile Zlib libraries:

#!/bin/sh
mkdir /usr/local/mips
#wget http://www.zlib.net/zlib-1.2.3.tar.gz # needs nothing
wget http://google-desktop-for-linux-mirror.googlecode.com/files/zlib-1.2.3.tar.gz
tar -xvzf zlib-1.2.3.tar.gz
cd ./zlib/1.2.3
make clean
export CFLAGS="-EL "
export CC="/opt/Sourcery_G++_Lite/bin/mips-linux-gnu-gcc"
export PATH=/opt/Sourcery_G++_Lite/bin:$PATH
export AR="/opt/Sourcery_G++_Lite/bin/mips-linux-gnu-ar rc"
export LDFLAGS=" -s -Xlinker -rpath /lib -Xlinker -rpath-link /opt/Sourcery_G++_Lite/lib/gcc/mips-linux-gnu/4.3.2/el"
./configure --prefix=/usr/local/mips
make

Once the compile is complete, you could also do a 'make install' to install the libraries into /usr/local/mips. This would be your target output folder to use for all cross-compiled targets. (Note in the example, we're using some extra LDFLAGS to produce a more compact binary.)