https://www.cberner.com/ Recent content on cberner.com Hugo en-us Mon, 12 Oct 2020 02:11:47 +0000 https://www.cberner.com/2020/10/12/building-fastest-raptorq-rfc6330-codec-rust/ Mon, 12 Oct 2020 02:11:47 +0000 https://www.cberner.com/2020/10/12/building-fastest-raptorq-rfc6330-codec-rust/ In my last blog post, I wrote about learning Rust and implementing the RaptorQ (RFC6330) fountain code. I only optimized the library for handling small message sizes, since it was mainly a project to help me learn Rust. However, since releasing it, a number of people have started using the raptorq crate, so I’ve been working on making it more polished. Shortly after open sourcing my initial implementation, someone pointed out that my library was slow for large numbers of symbols. https://www.cberner.com/2019/03/30/raptorq-rfc6330-rust-optimization/ Sat, 30 Mar 2019 02:11:47 +0000 https://www.cberner.com/2019/03/30/raptorq-rfc6330-rust-optimization/ I recently decided to learn more about Rust, and wrote a high performance RaptorQ (RFC6330) library. RaptorQ is a fountain code, and the core of the algorithm is a lot of matrix math over GF(256) – which translates into lots of XORs and reads from lookup tables. After getting the initial implementation working, I set about optimizing it. Below is a journal of the steps I took to profile and optimize the implementation. https://www.cberner.com/2017/12/03/installing-ubuntu-17-10-macbook-pro-retina-mid-2012/ Sun, 03 Dec 2017 23:45:00 +0000 https://www.cberner.com/2017/12/03/installing-ubuntu-17-10-macbook-pro-retina-mid-2012/ I skipped 17.04, since it didn’t seem to add much that I was excited about, but 17.10 has switched from Unity back to Gnome3, so I wanted to give it a try. I did a fresh install of 17.10 on my Macbook Pro Retina mid-2012 (rMBP 10,1). It continues to simplify the installation process, and seems quite stable so far. Improved from 16.10 No longer need to use rEFInd Hi-DPI scaling! https://www.cberner.com/2016/11/27/installing-ubuntu-16-10-macbook-pro-retina-mid-2012/ Sun, 27 Nov 2016 00:50:46 +0000 https://www.cberner.com/2016/11/27/installing-ubuntu-16-10-macbook-pro-retina-mid-2012/ I did a fresh install of 16.10 on my Macbook Pro Retina mid-2012 (rMBP 10,1). It seems quite stable so far, and brings a bunch of small improvements over 16.04. Improved from 16.04 Startup Disk Creator can be used for creating the ISO Installer works more smoothly Nvidia drivers no longer required for good performance Intel power management works correctly Now for the directions! 1. Resize Partitions This step is pretty straight-forward. https://www.cberner.com/2016/06/08/installing-ubuntu-16-04-macbook-pro-retina-101/ Wed, 08 Jun 2016 18:11:47 +0000 https://www.cberner.com/2016/06/08/installing-ubuntu-16-04-macbook-pro-retina-101/ I did a fresh install of 16.04 on my Macbook Pro (rMBP). It seems quite stable so far, and brings a number of improvements over 14.04. Improved from 14.04 No more special ISO (works with the default amd64 image) EFI is setup by default now Nvidia driver is automatically configured Now for the directions! 1. Resize Partitions This step is pretty straight-forward. Just open Disk Utility in OSX, and resize your existing OSX partition, so that there’s some free space for Ubuntu. https://www.cberner.com/2015/05/24/debugging-jvm-safepoint-pauses/ Sun, 24 May 2015 17:48:36 +0000 https://www.cberner.com/2015/05/24/debugging-jvm-safepoint-pauses/ I recently spent a bunch of time investigating why a Java application was spending a significant amount of time paused, even when garbage collection cycles were only taking ~200ms. The issue turned out to be other safepoints. For those that don’t know, the VM uses safepoints to perform a variety of internal operations, and they involve pausing every Java thread. Garbage collection is the most well known, but many other operations such as deoptimization, and revoking biased locks require a safepoint as well. https://www.cberner.com/2014/04/20/installing-ubuntu-14-04-on-macbook-pro-retina/ Mon, 21 Apr 2014 01:19:57 +0000 https://www.cberner.com/2014/04/20/installing-ubuntu-14-04-on-macbook-pro-retina/ I did an upgrade install of 13.10, so I skipped writing a blog post about it. However, I did a fresh install of 14.04 on my macbook pro (rMBP). It seems quite stable so far, and is mostly the same as 13.10 and 13.04. Improved from 13.04 Better nvidia support (no more need to set kernel options) Now for the directions! 1. Preparation Just follow steps 1 through 3 in my first guide, to get rEFIt installed and prepare to install Ubuntu. https://www.cberner.com/2013/03/01/installing-ubuntu-13-04-on-macbook-pro-retina/ Sat, 02 Mar 2013 07:43:29 +0000 https://www.cberner.com/2013/03/01/installing-ubuntu-13-04-on-macbook-pro-retina/ I’ve been using 13.04 (raring ringtail) daily build on my macbook pro (rMBP) for a couple days now, and things have been working great so far. Definitely a major improvement over 12.10, and for a daily build it’s been pretty stable too. Improved from 12.10 Better modesetting support in the kernel (no more need for nomodeset option) Proprietary Nvidia drivers finally work right New wifi drivers, that actually work! Now for the directions! https://www.cberner.com/2013/02/03/using-hostapd-on-ubuntu-to-create-a-wifi-access-point/ Mon, 04 Feb 2013 01:01:50 +0000 https://www.cberner.com/2013/02/03/using-hostapd-on-ubuntu-to-create-a-wifi-access-point/ I’ve been working on an autonomous hexacopter, which has a Pandaboard ES running Ubuntu on it, and I wanted it to setup its own wifi network in the field for easy ssh access. Turns out this is pretty simple to do, but you need to configure several different daemons to get it working right. 1. Check your wifi card You’ll need a wifi card that supports master mode, if you’re going to create an access point with it. https://www.cberner.com/2012/10/19/installing-ubuntu-12-10-on-macbook-pro-retina/ Fri, 19 Oct 2012 07:42:41 +0000 https://www.cberner.com/2012/10/19/installing-ubuntu-12-10-on-macbook-pro-retina/ Well, 12.10 (quantal quetzal) is out and runs a lot better on a Macbook Pro retina (rMBP) than 12.04. Just installed it on my retina and I think I can finally use it as my day to day laptop! Improved from 12.04 Better APIC support in the kernel (previous you had to boot with noapic) Special keys on keyboard work (volume control…etc) Better touchpad support (two-finger scrolling works!) Got full resolution and external monitor (edit: ran into some issues after trying to boot between OSX and Ubuntu, that I haven’t figured out yet) working! https://www.cberner.com/2012/07/10/installing-ubuntu-12-04-on-macbook-pro-retina/ Tue, 10 Jul 2012 22:09:08 +0000 https://www.cberner.com/2012/07/10/installing-ubuntu-12-04-on-macbook-pro-retina/ 1. Install rEFIt Download and mount the rEFIt-0.14.dmg disk image. Double-click on the “rEFIt.mpkg” package. Follow the instructions and select your Mac OS X installation volume as the destination volume for the install. If everything went well, you’ll see the rEFIt boot menu on the next restart. If you run into any problems, you can find more details on their website. 2. Resize Partitions This step is pretty straight-forward. Just open Disk Utility in OSX, and resize your existing OSX partition, so that there’s some free space for Ubuntu. https://www.cberner.com/2012/02/26/git-revision-numbers-for-setuptools-packages/ Sun, 26 Feb 2012 22:16:03 +0000 https://www.cberner.com/2012/02/26/git-revision-numbers-for-setuptools-packages/ Adding snapshot versions to your setuptools packages from SVN is easy, using the tag_svn_revision = true options in setup.cfg. However, getting this working for GIT proved to be more difficult, as there’s no built in support. However, I finally settled on a bash script that does the job quite nicely. now=`date +%s` gitversion=`git describe --long --dirty=-$now | sed 's/.\*(\[-\]\[0-9\]\[0-9]\*[-\]\[a-z0-9\]*)/1/'` python setup.py setopt -o tag_build -s $gitversion -c egg_info python setup.py sdist First we generate a unique version string, based on the number of commits since the last GIT tag: https://www.cberner.com/2011/12/11/pyflakes-error-in-eclim-on-ubuntu/ Mon, 12 Dec 2011 03:58:52 +0000 https://www.cberner.com/2011/12/11/pyflakes-error-in-eclim-on-ubuntu/ I started using Eclim a couple days ago, and kept running into Error running command: pyflakes <path to my code>, when my files contained more than one syntax error/warning. After a bit of googling I discovered this bug, which suggests that the version of pyflakes in Debian isn’t compatible with Eclim. Sure enough, removing the the .deb package (apt-get remove pyflakes) and installing it from pip (pip install pyflakes), fixed it. https://www.cberner.com/2010/05/17/programming-for-the-orangutan-svp-1284-on-ubuntu/ Tue, 18 May 2010 06:42:02 +0000 https://www.cberner.com/2010/05/17/programming-for-the-orangutan-svp-1284-on-ubuntu/ I just got my Orangutan SVP-1284, which uses the Atmega1284 processor. Getting your dev environment setup on Ubuntu is pretty easy: Download the prerequisites you need (http://www.pololu.com/docs/0J20/2) sudo apt-get install avr-libc gcc-avr avra binutils-avr avrdude Download the latest Pololu library from: http://www.pololu.com/docs/0J20/3 Extract the library, and install it. From the extracted directory run: sudo cp *.a /usr/lib/avr/lib/ && sudo cp -r pololu /usr/lib/avr/include/ As of version 5.10 of AVRDUDE, the default config file will not work. https://www.cberner.com/2010/03/27/robot-v0-1/ Sat, 27 Mar 2010 22:57:35 +0000 https://www.cberner.com/2010/03/27/robot-v0-1/ Well, I’ve moved on from LEDs, and built a little robot. It’s powered by a 16MHz Atmel chip, and currently you have to hard code instructions into it, but I’m hoping to add wireless control soon. Your browser does not support the HTML5 video tag. https://www.cberner.com/2010/03/20/fun-with-microcontrollers/ Sat, 20 Mar 2010 06:12:56 +0000 https://www.cberner.com/2010/03/20/fun-with-microcontrollers/ I decided to learn how to program microcontrollers. SparkFun has some really good tutorials http://www.sparkfun.com/commerce/tutorials.php. So far nothing too exciting, but I managed to compile and load the code onto the microcontroller and make a blinking LED =P Your browser does not support the HTML5 video tag. https://www.cberner.com/2010/03/14/first-post/ Sun, 14 Mar 2010 04:55:46 +0000 https://www.cberner.com/2010/03/14/first-post/ Well, WordPress is super easy to setup on Lunarpages. Now I just need a better theme…