I have previously shared how to install OpenCL™ on the Samsung XE303C12 Chromebook powered by the ARM® Mali™-T604 GPU. I have found that things are slightly different on the newer Samsung XE503C12 Chromebook ("Chromebook 2") powered by the ARM® Mali™-T628 GPU, so decided to provide an update. As before, please bear in mind that this is not ARM's "official guide" (which can be found here). However, it's a useful alternative to the official guide if, for example, you don't have a Linux PC or just want to use Chrome OS day in and day out.
You will need:
- Samsung Chromebook XE503C12 in Developer Mode
- A blank Micro SD card: 8 GB recommended (minimum 4 GB)
- Internet connection
How fast you will complete the installation will depend on how fast you can copy-and-paste instructions from this guide (Ctrl-C) into the shell (Shift-Ctrl-C), how fast your Internet connection is and how fast your memory card is. (I will give an approximate time for each step measured when using a rather slow 30 MB/s card). The basic OpenCL installation should take up to half an hour; PyOpenCL and NumPy about an hour; further SciPy libraries about 4 hours. Most of the time, however, you will be able to leave the Chromebook unattended, beavering away while compiling packages from source.
Finally, the instructions are provided "as is", you use them at your own risk, and so on, and so forth... (The official guide also contains an important disclaimer.)
Installing OpenCL
Enabling Developer Mode
NB: Enabling Developer Mode erases all user data - do a back up first.
Enter Recovery Mode by holding the ESC and REFRESH (↻ or F3) buttons, and pressing the POWER button. In Recovery Mode, press Ctrl+D and ENTER to confirm and enable Developer Mode.
Entering developer shell (1 min)
Open the Chrome browser and press Ctrl-Alt-T.
Welcome to crosh, the Chrome OS developer shell. If you got here by mistake, don't panic! Just close this tab and carry on. Type 'help' for a list of commands.
Don't panic, keep the tab opened and carry on to enter the shell:
crosh> shellchronos@localhost / $ uname -a Linux localhost 3.8.11 #1 SMP Wed Dec 10 14:41:54 PST 2014 armv7l SAMSUNG EXYNOS5 (Flattened Device Tree) GNU/Linux
Preparing a Micro SD card (5 min)
Insert a blank Micro SD card (denoted as /dev/mmcblk1 in what follows):
chronos@localhost / $ mount | grep "SD Card" /dev/mmcblk1p1 on /media/removable/SD Card type vfat (rw,nosuid,nodev,noexec,relatime,dirsync,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,flush,errors=remount-ro)
Unmount the card and run fdisk:
chronos@localhost / $ sudo umount /dev/mmcblk1p1chronos@localhost / $ sudo /sbin/fdisk /dev/mmcblk1Welcome to fdisk (util-linux 2.24).
Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help):
Enter 't' to change a partition type, then '83' to change the partition type to 'Linux', and finally 'w' to apply the change:
Command (m for help): t Selected partition 1 Hex code (type L to list all codes): 83 If you have created or modified any DOS 6.x partitions, please see the fdisk documentation for additional information. Changed type of partition 'W95 FAT32 (LBA)' to 'Linux'. Command (m for help): w The partition table has been altered. Calling ioctl() to re-read partition table. Syncing disks. chronos@localhost / $
Format the card e.g. using ext3:
chronos@localhost / $ sudo /sbin/mkfs.ext3 /dev/mmcblk1p1
NB: If you use a card that is less than 8 GB, you may need to reserve enough inodes when you format the card e.g.:
chronos@localhost / $ sudo /sbin/mkfs.ext3 /dev/mmcblk1p1 -j -T small
Mount the card and check that it's ready:
chronos@localhost / $ sudo mkdir -p ~/gentoochronos@localhost / $ sudo mount -o rw,exec -t ext3 /dev/mmcblk1p1 ~/gentoochronos@localhost / $ df -h ~/gentoo Filesystem Size Used Avail Use% Mounted on /dev/mmcblk1p1 15G 38M 14G 1% /home/chronos/user/gentoochronos@localhost / $ df -hi ~/gentoo Filesystem Inodes IUsed IFree IUse% Mounted on /dev/mmcblk1p1 951K 11 951K 1% /home/chronos/user/gentoo
Installing Gentoo Linux (15 min)
chronos@localhost / $ cd ~/gentoochronos@localhost ~/gentoo $ ls -la total 32 drwxr-xr-x 3 root root 4096 Dec 9 21:31 . drwx--x--- 30 chronos chronos-access 12288 Dec 9 21:38 .. drwx------ 2 root root 16384 Dec 9 21:31 lost+found
Download the latest stage 3 archive for armv7a_hardfp:
chronos@localhost ~/gentoo $ sudo wget http://distfiles.gentoo.org/releases/arm/autobuilds/latest-stage3-armv7a_hardfp.txtchronos@localhost ~/gentoo $ sudo wget http://distfiles.gentoo.org/releases/arm/autobuilds/`cat latest-stage3-armv7a_hardfp.txt | grep stage3-armv7a_hardfp`
Extract the downloaded archive right onto the card e.g.:
chronos@localhost ~/gentoo $ sudo tar xjpf stage3-armv7a_hardfp-20141023.tar.bz2
Clean up:
chronos@localhost ~/gentoo $ sudo rm latest-stage3-armv7a_hardfp.txtchronos@localhost ~/gentoo $ sudo rm stage3-armv7a_hardfp-20141023.tar.bz2
Downloading OpenCL drivers (4 min)
Go to the page listing Mali-T6xx Linux drivers and download release r4p0-02rel0 for Mali-T62x fbdev (mali-t62x_r4p0-02rel0_linux_1+fbdev.tar.gz). Make sure you carefully read and accept the associated licence terms.
chronos@localhost ~/gentoo $ sudo tar xvzf ~/Downloads/mali-t62x_r4p0-02rel0_linux_1+fbdev.tar.gz
This will create ~/gentoo/fbdev which we will use later.
Entering Gentoo Linux (2 min)
Similar to crouton, we will use chroot to enter our Linux environment.
Create two scripts and make them executable:
chronos@localhost ~/gentoo $ sudo vim ~/gentoo/setup.sh #!/bin/sh GENTOO_DIR=/home/chronos/user/gentoo mount -t proc /proc $GENTOO_DIR/proc mount --rbind /sys $GENTOO_DIR/sys mount --rbind /dev $GENTOO_DIR/dev cp /etc/resolv.conf $GENTOO_DIR/etcchronos@localhost ~/gentoo $ sudo vim ~/gentoo/enter.sh #!/bin/sh GENTOO_DIR=/home/chronos/user/gentoo LC_ALL=C chroot $GENTOO_DIR /bin/bashchronos@localhost ~/gentoo $ sudo chmod u+x ~/gentoo/setup.sh ~/gentoo/enter.sh
Execute the scripts:
chronos@localhost ~/gentoo $ sudo ~/gentoo/setup.shchronos@localhost ~/gentoo $ sudo ~/gentoo/enter.sh
Note that the ~/gentoo directory will become the root (/) directory once we enter our new Linux environment. For example, ~/gentoo/fbdev will become /fbdev inside the Linux environment.
Installing OpenCL header files (2 min)
Download OpenCL header files from the Khronos OpenCL registry:
localhost / # mkdir /usr/include/CL && cd /usr/include/CLlocalhost / # wget http://www.khronos.org/registry/cl/api/1.1/opencl.hlocalhost / # wget http://www.khronos.org/registry/cl/api/1.1/cl_platform.hlocalhost / # wget http://www.khronos.org/registry/cl/api/1.1/cl.hlocalhost / # wget http://www.khronos.org/registry/cl/api/1.1/cl_gl.hlocalhost / # wget http://www.khronos.org/registry/cl/api/1.1/cl_ext.h
Installing OpenCL driver (2 min)
Change properties on the downloaded OpenCL driver files and copy them to /usr/lib:
localhost / # chown root /fbdev/*localhost / # chgrp root /fbdev/*localhost / # chmod 755 /fbdev/*localhost / # mv /fbdev/* /usr/liblocalhost / # rmdir /fbdev
Summary
By now you should have a mint Linux installation complete with the OpenCL drivers and headers, so you can start playing with OpenCL!
When you reboot, you just need to mount the card and execute the setup script again:
chronos@localhost / $ sudo mount -o rw,exec -t ext3 /dev/mmcblk1p1 ~/gentoochronos@localhost / $ sudo ~/gentoo/setup.sh
Then you can pop in and out of the Linux environment with:
chronos@localhost / $ sudo ~/gentoo/enter.shlocalhost / # exitchronos@localhost / $
But the fun just begins here! Follow the instructions below to install PyOpenCL and SciPy libraries for scientific computing.
Installing PyOpenCL
Configuring Portage (15 min)
Portage is Gentoo's package management system.
localhost / # echo "MAKEOPTS=\"-j4\"" >> /etc/portage/make.conflocalhost / # echo "ACCEPT_KEYWORDS=\"~arm\"" >> /etc/portage/make.conflocalhost / # mkdir /etc/portage/profilelocalhost / # mkdir /etc/portage/package.uselocalhost / # mkdir /etc/portage/package.unmasklocalhost / # mkdir /etc/portage/package.accept_keywordslocalhost / # mkdir /etc/portage/package.keywordslocalhost / # touch /etc/portage/package.keywords/dependences
Perform an update:
localhost / # emerge --sync --quietlocalhost / # emerge --oneshot portagelocalhost / # eselect news read
NB: If any emerge command below fails, rerun it with the --autounmask-write flag; then run etc-update and answer '-3' followed by 'y'. Running emerge again should now get the build started e.g.:
localhost / # emerge --autounmask-write dev-python/pandaslocalhost / # etc-update Scanning Configuration files... The following is the list of files which need updating, each configuration file is followed by a list of possible replacement files. 1) /etc/portage/package.keywords/dependences (1) Please select a file to edit by entering the corresponding number. (don't use -3, -5, -7 or -9 if you're unsure what to do) (-1 to exit) (-3 to auto merge all files) (-5 to auto-merge AND not use 'mv -i') (-7 to discard all updates) (-9 to discard all updates AND not use 'rm -i'): -3 Replacing /etc/portage/package.keywords/dependences with /etc/portage/package.keywords/._cfg0000_dependences mv: overwrite '/etc/portage/package.keywords/dependences'? y Exiting: Nothing left to do; exiting.localhost / # emerge dev-python/pandas
Selecting Python 2.7 (1 min)
localhost / # eselect python set python2.7
Installing NumPy (40 min)
Install NumPy with LAPACK as follows.
localhost / # echo "dev-python/numpy lapack" >> /etc/portage/package.use/numpylocalhost / # echo "dev-python/numpy -lapack" >> /etc/portage/profile/package.use.masklocalhost / # emerge dev-python/numpylocalhost / # python -c "import numpy; print numpy.__version__" 1.9.1
Installing PyOpenCL (7 min)
localhost / # cd /tmplocalhost tmp # wget https://pypi.python.org/packages/source/p/pyopencl/pyopencl-2014.1.tar.gzlocalhost tmp # tar xzf pyopencl-2014.1.tar.gzlocalhost tmp # cd pyopencl-2014.1localhost pyopencl-2014.1 # python configure.pylocalhost pyopencl-2014.1 # make installlocalhost pyopencl-2014.1 # cd exampleslocalhost examples # python demo.py Choose device(s): [0] <pyopencl.Device 'Mali-T628' on 'ARM Platform' at 0x-49b96370> [1] <pyopencl.Device 'Mali-T628' on 'ARM Platform' at 0x-49b96270> Choice, comma-separated [0]:0 Set the environment variable PYOPENCL_CTX='0' to avoid being asked again. (0.0, 241.52145)localhost examples # python -c "import pyopencl; print pyopencl.VERSION_TEXT" 2014.1
(That's right! The Exynos 5420 chip effectively has two Mali-T62x GPUs: GPU 0 has 4 cores; GPU 1 has 2 cores. How cool is that?)
Installing scientific libraries
If you would like to follow my posts on benchmarking (e.g. see the intro), I recommend you install packages from the SciPy family.
Installing IPython (45 min)
localhost / # emerge dev-python/ipythonlocalhost / # ipython --version 2.3.1
Installing IPython Notebook (5 min)
Install IPython Notebook to enjoy a fun blend of Chrome OS and IPython experience.
localhost / # emerge dev-python/jinja dev-python/pyzmq www-servers/tornadolocalhost / # ipython notebook 2014-05-08 06:49:08.424 [NotebookApp] Using existing profile dir: u'/root/.ipython/profile_default' 2014-05-08 06:49:08.440 [NotebookApp] Using MathJax from CDN: http://cdn.mathjax.org/mathjax/latest/MathJax.js 2014-05-08 06:49:08.485 [NotebookApp] Serving notebooks from local directory: / 2014-05-08 06:49:08.485 [NotebookApp] The IPython Notebook is running at: http://127.0.0.1:8888/ 2014-05-08 06:49:08.486 [NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation). 2014-05-08 06:49:08.486 [NotebookApp] WARNING | No web browser found: could not locate runnable browser.
Open http://127.0.0.1:8888/ in a new Chrome tab to start creating your own IPython Notebooks!
Installing Matplotlib (50 min)
localhost / # emerge dev-python/matplotliblocalhost / # python -c "import matplotlib; print matplotlib.__version__" 1.4.2
Installing SciPy (60 min)
localhost / # emerge sci-libs/scipylocalhost / # python -c "import scipy; print scipy.__version__" 0.14.0
Installing Pandas (80 min)
localhost / # emerge dev-python/pandaslocalhost / # python -c "import pandas; print pandas.__version__" 0.14.1