Intro

"Buildroot is a simple, efficient and easy-to-use tool to generate embedded Linux systems through cross-compilation." This is a simple guide to compilation of buildroot on the SoCFPGA platform. Although we could use Buildroot to download the toolchain, and compile the kernel this guide does not do so.

Setup and Download

Get and extract the sources for buildroot, the toolchain, and the linux-socfpga sources from rocketboards.For these steps, I am not using git but obviously git could be used.

mkdir socfpga_buildroot
cd socfpga_buildroot
wget http://releases.linaro.org/14.09/components/toolchain/binaries/gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz

the above link seems obsolete ! try this: wget http://releases.linaro.org/archive/14.09/components/toolchain/binaries/gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz

wget http://buildroot.uclibc.org/downloads/buildroot-2014.08.tar.gz
wget -O socfpga-3.10-ltsi.tgz https://github.com/altera-opensource/linux-socfpga/tarball/socfpga-3.10-ltsi

mkdir toolchain
tar -xvf gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz --strip-components 1 -C toolchain

mkdir buildroot
tar -xzvf buildroot-2014.08.tar.gz --strip-components 1 -C buildroot

mkdir linux-socfpga
tar -xzvf socfpga-3.10-ltsi.tgz --strip-components 1 -C linux-socfpga

Buildroot Configuration

A few screenshots regarding basic buildroot configuration for SoCFPGA.Again, not compiling the kernel or uboot with the buildroot flow.

Launch Buildroot's menuconfig, this command assumes you are in the socfpga_buildroot directory with the toolchain, linux-socfpga, and buildroot subdirectories.

make -C buildroot ARCH=ARM BR2_TOOLCHAIN_EXTERNAL_PATH=$(pwd)/toolchain menuconfig

Linux Configuration

I'm not going to add much detail for this, just using the basic defconfig available for socfpga_cyclone5

make -C linux-socfpga ARCH=arm CROSS_COMPILE=$(pwd)/toolchain/bin/arm-linux-gnueabihf- socfpga_defconfig

Build Everything

Like the heading says...

make -C linux-socfpga ARCH=arm CROSS_COMPILE=$(pwd)/toolchain/bin/arm-linux-gnueabihf- zImage
make -C buildroot ARCH=ARM BR2_TOOLCHAIN_EXTERNAL_PATH=$(pwd)/toolchain all

In Conclusion

So what do we have?

First we have the kernel in a vmlinux and a zImage

[dwesterg@sj-dwesterg-ll build]$ ls linux-socfpga/vmlinux
linux-socfpga/vmlinux
[dwesterg@sj-dwesterg-ll build]$ ls linux-socfpga/arch/arm/boot/zImage 
linux-socfpga/arch/arm/boot/zImage
[dwesterg@sj-dwesterg-ll build]$ 

And on the Buildroot side

[dwesterg@sj-dwesterg-ll build]$ ls buildroot/output/images/
rootfs.cpio  rootfs.ext2  rootfs.ext3  rootfs.jffs2  rootfs.tar
[dwesterg@sj-dwesterg-ll build]$ 

Lastly..

You can have alot of fun automating builds and using overlays to customize your rootfs. In the files associated with this wiki entry is a tar (socfpga_buildroot_2014_10_16.tgz) including a Makefile that builds all of the above and a quartus project for the Altera CycloneV. The output is a zImage and vmlinux including an initramfs and a kernel wrapped with a devicetree file.

Make sure you have the Quartus 14.0 and SoCEDS and ARM Development Studio 14.0 tools in the path.

It downloads everything ..

westerg@sj-dwesterg-ll socfpga_buildroot]$ make all

comment: following the above procedure, at this point, in folder "socfpga_buildroot" there isn't any makefile !!! so i don't understand this "make all" instruction


wget -O downloads/linux-socfpga.tgz "http://rocketboards.org/gitweb/?p=linux-socfpga.git;a=snapshot;h=refs/heads/socfpga-3.10-ltsi;sf=tgz"
--2014-10-15 14:05:45--  http://rocketboards.org/gitweb/?p=linux-socfpga.git;a=snapshot;h=refs/heads/socfpga-3.10-ltsi;sf=tgz

comment: the above link don't work !!


Resolving rocketboards.org (rocketboards.org)... 54.243.129.218
Connecting to rocketboards.org (rocketboards.org)|54.243.129.218|:80... connected.
HTTP request sent, awaiting response... 

Compiles everything ..

make -C /data/dwesterg/socfpga/socfpga_buildroot/build/linux-socfpga ARCH=arm KBUILD_BUILD_VERSION="2014-10-15---14-08-16"  CROSS_COMPILE=/data/dwesterg/socfpga/socfpga_buildroot/build/toolchain/bin/arm-linux-gnueabihf- CONFIG_DTB_SOURCE=/data/dwesterg/socfpga/socfpga_buildroot/quartus/soc_system.dts INSTALL_MOD_PATH=/data/dwesterg/socfpga/socfpga_buildroot/build/overlay modules
make[1]: Entering directory `/data/dwesterg/socfpga/socfpga_buildroot/build/linux-socfpga'
scripts/kconfig/conf --silentoldconfig Kconfig 

And spews out the results ..

make[1]: Leaving directory `/data/dwesterg/socfpga/socfpga_buildroot/build/linux-socfpga'
mkdir -p -p /data/dwesterg/socfpga/socfpga_buildroot/output
cp -rf /data/dwesterg/socfpga/socfpga_buildroot/build/linux-socfpga/vmlinux /data/dwesterg/socfpga/socfpga_buildroot/output/vmlinux
mkdir -p -p /data/dwesterg/socfpga/socfpga_buildroot/output
cp -rf /data/dwesterg/socfpga/socfpga_buildroot/build/linux-socfpga/arch/arm/boot/zImage /data/dwesterg/socfpga/socfpga_buildroot/output/zImage
[dwesterg@sj-dwesterg-ll socfpga_buildroot]$ ls output/
vmlinux  zImage
[dwesterg@sj-dwesterg-ll socfpga_buildroot]$ ls build/
buildroot  linux-socfpga  overlay  toolchain
[dwesterg@sj-dwesterg-ll socfpga_buildroot]$ ls quartus/
boot.script              db                  hps_common_board_info.xml  ip             soc_system_board_info.xml  soc_system.qsf         stamp
c5_pin_model_dump.txt    ds5                 hps_isw_handoff            Makefile       soc_system.dtb             soc_system.qsys        u-boot.scr
create_ghrd_qsys.tcl     ghrd_reset.tcl      hps_sdram_p0_all_pins.txt  output_files   soc_system.dts             soc_system.sopcinfo
create_ghrd_quartus.tcl  ghrd_sc_script.tcl  hps_sdram_p0_summary.csv   sd_fat.tar.gz  soc_system_hw.tcl          soc_system_timing.sdc
cti_tapping.stp          ghrd_top.v          incremental_db             soc_system     soc_system.qpf             software
[dwesterg@sj-dwesterg-ll socfpga_buildroot]$