Buildroot fork for EL32 Embedded Linux course.
This repository contains support for building an Embedded Linux distribution (kernel, rootfilesystem) and a crosscompilation toolchain.
Install required tools:
$ sudo apt-get install -y build-essential libncurses5-dev whois git subversion parted kpartx extlinux qemu qemu-system putty
Clone this repository:
git clone --depth 1 https://github.com/fhict/el32-buildroot.git buildroot
Build an Embedded Linux distribution and crosscompilation toolchain for the Soekris NET4801 board.:
$ cd buildroot
$ make soekris_net4801_defconfig
$ make
Now you will have to wait quite a while for it to complete. If everything went well a kernel (bzImage), a root filesystem (rootfs), and a bootable disk image (soekris.img) will be available in the directory output/images/.
The toolchain generated by Buildroot is located by default in output/host/. The simplest way to use it is to add output/host/usr/bin/ to your PATH environment variable (export PATH=$PATH:$HOME/buildroot/output/host/usr/bin). To make this permament enter it in your .bashrc file (echo 'export PATH=$PATH:$HOME/buildroot/output/host/usr/bin' >> ~/.bashrc). You can then use the crosscompilers simply as i586-linux-gcc (C compiler) and i586-linux-g++ (C++ compiler) without a path prefix.
The disk image should be written on a CompactFlash (CF) card and inserted in the Soekris board. Writing the image on the CF card can be done as follows:
$ sudo umount /dev/sdc*
$ sudo dd if=output/images/soekris.img of=/dev/sdc bs=1M
$ sudo sync
Above command assumes the CF card reader is connected as /dev/sdc. Check the output of the command dmesg | tail directly after inserting a CF card to see if this is the case. If not change the device name to comply with your configuration.
To test the kernel and rootfs with QEMU:
$ qemu-system-i386 -kernel output/images/bzImage -append "root=/dev/sda panic=1 console=ttyS0" -no-reboot -serial stdio -hda output/images/rootfs.ext2
This command will boot a virtualized Soekris. In fact it is running the Soekris root filesystem on a virtualized PC.
After booting the real or the virtual Soekris you should be able to login as root with password root.
Build an Embedded Linux distribution and crosscompilation toolchain for the Raspberri Pi.:
$ cd buildroot
$ make raspberrypi_defconfig
$ make
Now you will have to wait quite a while for it to complete. If everything went well a kernel (zImage), a root filesystem (rootfs), and a bootable disk image (rpi.img) will be available in the directory output/images/.
The toolchain generated by Buildroot is located by default in output/host/. The simplest way to use it is to add output/host/usr/bin/ to your PATH environment variable (export PATH=$PATH:$HOME/buildroot/output/host/usr/bin). To make this permament enter it in your .bashrc file (echo 'export PATH=$PATH:$HOME/buildroot/output/host/usr/bin' >> ~/.bashrc). You can then use the crosscompilers simply as arm-linux-gcc (C compiler) and arm-linux-g++ (C++ compiler) without a path prefix.
The disk image should be written on a SD card and inserted in the Raspberry Pi. Writing the image on the SD card can be done as follows:
$ sudo umount /dev/mmcblk0*
$ sudo dd if=output/images/rpi.img of=/dev/mmcblk0 bs=4M
$ sudo sync
Above command assumes the SD card reader is connected as /dev/mmcblk0. Check the output of the command dmesg | tail directly after inserting a SD card to see if this is the case. If not change the device name to comply with your configuration.
To test the kernel and rootfs with QEMU first download a suitable qemu compatible kernel:
$ wget http://xecdesign.com/downloads/linux-qemu/kernel-qemu
Then start QEMU with your new rootfilesystem:
$ qemu-system-arm -M versatilepb -cpu arm1176 -m 256 -kernel kernel-qemu -append "root=/dev/sda panic=1 console=ttyAMA0" -no-reboot -serial stdio -hda output/images/rootfs.ext2
This command will boot a virtualized Raspberry Pi. In fact it is running the Rapberry Pi root filesystem on a virtualized VersatilePB board.
After booting the real or the virtual Raspberry Pi you should be able to login as root with password root.