Zygo Blaxell

A current version of this resume is available at http://www.hungrycats.org/~zblaxell/resume.html

Contact Information

E-mail: zblaxres@hungrycats.org
Location: Ottawa, Ontario, Canada

Profile

An accomplished problem solver with 16 years of experience in systems-level software development and information technology operations, building mission-critical systems from open-source tools. Key strengths include a demonstrated eagerness to learn, an impatient desire to get things done, and fanatical attention to detail. Equally comfortable with highly structured, peer-reviewed product change management processes and MacGyverish mash-ups of software and hardware.

Skills and Experience Summary Table

10-15 Years Experience

Linux	Application development, system administration, network administration, kernel and device driver development, security analysis, software porting. Experienced with Debian, Ubuntu and Red Hat distributions, OpenEmbedded (Angstrom, custom). Maintained packages for Xandros. Built custom root filesystems from source.
GNU Toolchain	C/C++ development tools (gcc/g++, gdb, make, autoconf, automake, libtool, cross-compilation, Android SDK, OpenEmbedded, qemu, ltrace, strace, valgrind). SCM system administration and build system integration, including git, Subversion (SVN) and CVS.
Shell scripting	Bourne shell, csh, sed, awk, regular expressions, build systems, system monitoring, etc.
Perl	Database administration, web development, application proxies, log analysis and reporting tools, cross-platform testing, debugging third-party scripts. Catalyst, Rose::DB::Object, Template Toolkit, mod_perl.
Information Security	Internet firewall design and implementation, security policy, code audit and verification, intrusion analysis and recovery, Linux/Unix host security, some cryptography.
Internet-facing Server Administration	Apache, Perl, CGI, INN, Bugzilla, MediaWiki, sendmail, exim, postfix, bind on Linux. Server configuration, application development, security auditing. Customised implementations of SMTP, NNTP, POP3, HTTP protocol servers and proxies. Redundant server implementation, load-balancing, fail-over.
C++	Developing and porting applications (GNU g++ on Linux/Unix and Win32). Custom EDA tools, large image (hundreds of gigapixels) processing, UI development. Cross-platform development, 32- to 64-bit migrations, ARM ports.
C	C programming on Linux, with some experience with Android, other Unix environments, and Microware OS-9. Strong knowledge of ANSI standards and portable software development techniques. Debugging 3rd-party programs and libraries.

5-10 Years Experience

Tcl/Tk	Tcl as a portable runtime layer and simulation control language, embedded device control applications, GUI development, distributed processing using mobile agents, IRC information system robots. Some GUI programming with Tcl/Tk.
Device drivers	Wrote device drivers for sensors (magnetic, light, temperature, image), digital cameras, FM radio tuners, power switch relays, servo motor control systems. Designed and built some of the hardware as well.
non-x86 CPU Architectures	Developed, maintained, or ported software to Alpha, AMD64, ARM, MIPS, and Sparc.
Qt	Developed software to support read-back of circuitry from images of integrated circuits. Tuned performance of drawing operations. Implemented database interface layer for EDA application. Built custom UI for Bluetooth pairing and device management. Developed multi-platform GUI tool to configure OMAP-based medical devices.

2-4 Years Experience

Assembly Language	Motorola 6809, Intel 8051, 8086, MIPS. Microware OS-9 real-time operating system. Microcontroller-driven embedded systems.
Bluetooth	Integrated bluez Bluetooth stack into embedded Linux builds. Implemented configuration UI and customised automation for HFP, HSP, A2DP, OBEX FTP/OPP, GAP, DUN, PAN profiles and GPS receivers.

1 Year Experience or Less

OpenEmbedded	Built custom Linux system images based on Angstrom for Logic OMAP 3530 LV-SOM reference boards with proprietary hardware expansion cards. Optimized build system to reduce image size, boot time and build time.
Android	Built Android SDK and installing system image on Qualcomm reference board. Enabled the bluez Bluetooth stack in Android and installed third-party Java .apk files to provide UI.
Miscellaneous Unix-Like OS	FreeBSD, AIX, HP-UX, Ultrix, EP/IX software development.

Software Development Work Experience

eSight (2010)

Mandate: Develop software as required to drive an OMAP-based vision enhancement device.

Built Linux system images for OMAP 3530 LV-SOM with custom expansion boards.
Customized Angstrom and Minimal OpenEmbedded distributions to reduce build and boot times.
Integrated Linux kernel and u-boot patches from TI, Logic, mailing lists, and other sources as they became available.
Debugged drivers for USB HID devices, I2C, network, MTD, Compact Flash, video sensors and displays.
Ported board support patches from 2.6.28 to 2.6.32.
Designed software to configure and calibrate the software running on the OMAP device from a PC workstation.
Integrated support for the configuration software into existing OMAP application code.

Xandros (2009)

Mandate: Integrate the Linux Bluetooth stack with Xandros's Linux products.

Consulted with marketing to define Bluetooth capabilities for product designs and contract development bids.
Developed demo applications using QT 4.5 in C++ to perform Bluetooth tasks such as device discovery, pairing, HID, and OBEX file transfer on x86, AMD64, and ARM platforms.
Integrated Bluetooth support into an Android-based system image for a Qualcomm Snapdragon board and a Xandros-based system image for a Freescale i.MX board.
Fixed bugs in Linux kernel, BlueZ, and Pulseaudio, and submitted patches to Xandros package maintainers and to upstream open-source community maintainers.
Supported developers integrating Bluetooth support into Xandros x86 OS products.
Contributed to Xandros's git-based automatic build system for ARM packages.
Routine integration testing with new Linux kernel, bluez, gstreamer, and Pulseaudio releases.

Roaring Penguin Software (2008)

Mandate: Develop web-based application software for an ad-driven web site using Linux, Apache, PostgreSQL, and Perl.

Designed and implemented business objects with Rose::DB::Object, Template::Toolkit, and Catalyst.
Contributed to product design and system architecture.
Participated in PgCon 2008 PostgreSQL conference.

Chipworks (2000-2007)

Mandate: Design, develop, support, and maintain critical in-house applications for automated image acquisition of integrated circuits and subsequent electrical analysis of the image data. Contribute Linux expertise to the IT department. Provide support to lab operations.

Designed architecture of image capture software for SEM (scanning electron microscope) imaging.
Provided documentation during negotiations with suppliers to ensure that the image acquisition system would satisfy technical requirements.
Significantly improved performance in image retrieval and display functions of Chipworks proprietary Qt applications using tools such as gprof, gdb, gcov, strace, ltrace, and valgrind.
Integrated support for new camera and motion control devices into Chipworks proprietary image capture applications.
Designed and implemented software and operational procedures for correcting registration and calibration problems in image data, reducing or eliminating the need to re-shoot images in most cases.
Designed and implemented a number of distributed image processing systems as required to match changing computational capabilities with changing operational requirements.
Implemented PDF report generator used by the Report Production department to generate reports on paper or PDF for delivery to customers.
Maintained Chipworks software on x86 Linux, Sparc Solaris and Alpha Linux platforms.
Participated in code and design reviews with other developers.
Developed Linux device drivers for:
- microscope cameras (Polaroid DMC1E, DMC2P; Hamamatsu C4880)
- temperature sensors (HotLittleTherm, Dallas Semiconductor)
- robotic stages (Newport, Precision Instrument)
- frame grabber cards (Imaging Technologies Inc.)
Instrumented a Linux kernel to capture data passing through the SCSI bus for analysis.
Extended the Linux device driver for Promise IDE cards to support some versions of the FastTrak 66, 100 and 133 controllers. Contributed patches to Linux kernel.
Reverse engineered Windows device drivers to develop Linux drivers when not supplied by the device vendor or Linux community.
Acted as technical consultant to the R&D group, and resolved problems with Linux, Debian, PostgreSQL, Qt, Tcl/Tk, ATI and Matrox video drivers, and GNU C++ toolchain.
Developed custom scripts using the Tcl API embedded in the Chipworks software to resolve special-case problems for engineers.
Implemented a monitoring and reporting system for temperature sensors in Chipworks image capture labs. Quantified the relationship between temperature stability and operational efficiency of the image capture systems.
Analysed log data generated by automated image capture systems when these systems failed. Devised workarounds for several problems which extended the service life of some equipment for a number of years.

Corel Corporation (1999)

Mandate: Extend the open-source Wine software to provide Win32 API routines required to implement a Linux port of Corel desktop applications. Provide technical support for the Corel Linux desktop software group.

Wrote a translator for DOS NMAKE and BAT files that allows scripts which normally build software on Windows to build the same software on Linux with little modification.
Devised a simple regression test suite for Wine. Reports generated by the suite included automated image analysis and post-processed image display which detected changes in the visual appearance of GUI applications.
Implemented a gateway between external Wine mailing lists and internal NNTP servers, which was used by all of the Linux teams within Corel.
Built and maintained Linux master server (providing servers for WWW, SMB, NFS, and CVS, as well as group data storage) for the Corel Draw Wine porting team.
Built packages in Debian's packaging format (.deb) for Corel's Linux distribution.
Audited Corel software for its Linux distribution. Discovered instances of buffer overruns and insecure use of temporary files in the code. Determined the root cause for each of these instances and documented an approach to resolve each root cause. Recommended training for developers so that they could recognise and avoid such problems in the future.

Myrus Design (1995-1997)

Mandate: Set up and maintain automated testing systems and source code revision control, port the software and verify consistent operation on all supported platforms, and create packages for end-user distribution; to perform internal IS functions ranging from end-user desktop support to security administration; and to operate the corporate Internet servers.

Maintain and extend Myrus' flagship product: a CAD data translator and reporting system for printed-circuit board (PCB) manufacturing users.
Designed cross-platform testing tools and automated testing procedures in Perl, Tcl/Tk, Bourne shell, C, and C++ on Solaris/Sparc, Solaris/x86, Linux, Windows 95 and NT.
Ported Myrus software from SunOS to Linux and Solaris and contributed to Windows 95/NT ports.
Developed prototype web-based CAD data translation server based on Myrus tools.
Developed a fax-to-WWW gateway, which allowed authorised users to view PDF files of incoming faxes, using Linux tools integrated with a CGI script.
Assembled, configured, and upgraded PC hardware used by Myrus.
Designed and implemented a network firewall based on Linux and transparent proxy tools, but customised for extra paranoia.
Audited software for use by external users on company servers for security purposes. Found a number of serious security problems and followed through to the vendor with analysis and fixes.
Developed web-based chat software for internal use (used by employees, suppliers, and clients) based on Linux, Perl, and Apache.
Implemented special-purpose customised servers, clients, and gateways for NNTP, HTTP, FTP, and SMTP to reduce costs, meet security requirements, or adapt legacy systems to changes in technology and practice.

Various Contracts (1993-1997)

Mandate: Technical consulting under contract with various clients.

Built automated email-to-fax gateway software services based on Linux, Ghostscript, and Hylafax.
Developed firmware for an Intel 8051 microcontroller embedded in a satellite receiver system. Improved performance over previous firmware version by 300%.
Installed and configured a Linux-based web server for a research group in the Waterloo science faculty.
Advised faculty of engineering staff about security problems on X11 terminals in a student engineering lab, and how to fix them.
Security consultant for a small Ottawa software company. Rebuilt a web server that had been compromised by intruders and made several recommendations for system maintenance procedures to prevent a recurrence.
Volunteer elected system administrator of Solaris and Linux machines for the University of Waterloo Computer Science Club.
Designed, purchased, and built sensor and control circuits for Computer Science Club office doors, lights, and stereo.

Open-Source Software Contributions (1992-present)

http://www.hungrycats.org/~zblaxell/projects/projects.html

Open-source free software projects I have contributed to, and which are not otherwise listed above:

Volunteer support for local Ottawa Linux Users Group (OCLUG) and bluez.org Linux Bluetooth stack users via IRC and mailing lists.
Released filereaper, a Perl script for real-time, secure, on-demand deletion of temporary files. Red Hat Software and Debian GNU/Linux used ideas from this script for their tmpwatch and tmpreaper utilities.
Released faster-dupemerge, the latest in a series of several programs designed to reduce disk space usage by identifying identical files in a filesystem and replacing them with hard links to a single instance of each unique file's content.
Resolved dozens of bugs in the Debian Linux distribution by providing detailed bug reports, scripts to reproduce problems, technical analysis, or patches as required.
Contributed to the design of the interface renaming feature for Linux network firewalls implemented in Linux 2.1 to replace features removed during the transition from ipfwadm in Linux 2.0 to ipchains in Linux 2.1.
Contributed to design of /dev/vcs interface for Linux 1.2, while auditing security problems in the VGA console driver.
Fixed bugs in the OSS Gravis Ultra Sound device driver for Linux using technical specifications downloaded from the chipset manufacturer's web site.
cddamp3, an application that converts audio CDs into MPEG Layer 3 compressed audio files using machines on a LAN in parallel. Includes a SCSI device driver for extracting CD digital audio data without D/A/A/D conversion and an algorithm that detects and compensates for incorrect data read from the CD-ROM drive. Implemented in Tcl and C++ for Linux.
mj, an application that schedules and plays MPEG Layer 3 files on Linux with cross-fade effects between files and automatic gain control to normalise volume levels. Written in C++ for Linux and Solaris with POSIX real-time extensions.
digitz, sound sampling software and device driver in Motorola 6809 assembler for Microware OS-9.

Awards

Chipworks "Top Metal" award for contributions to a software-controlled image acquisition system using a scanning electron microscope (SEM).
Member of 10th place team, 1994 ACM International Collegiate Programming Contest held in Nashville, Tennessee.
Member of 1st place team, 1994 ACM East Central Regional Programming Contest held at the University of Waterloo.
1st place, Spring 1994 Computer Science Club (CSC) programming contest at the University of Waterloo.
4th place, Fall 1993 CSC programming contest. Alternate team member for University of Waterloo team in the ACM regional programming contest.

Education

Bachelor of Mathematics/Computer Science program at the University of Waterloo (partially completed).

Interests and Self-initiated Projects

Wrote an extension for XChat (IRC client) which converts IRC text into speech, and built a mash-up of services around it:
- Different IRC users are given different "voices", by adjusting pitch, speed, and accent of the speech according to parameters derived from a hash of the user's name.
- Proxy on a stable server machine hides the mobile client device's intermittent connectivity from the Internet, and buffers messages while offline.
- Pauses media player while reading text, then resumes media play automatically.
- Speaks incoming messages from IM services including Yahoo! Messenger, Windows Live (MSN), Google Talk (Jabber).
- Reads From/Subject headers from incoming email, with special processing for Bugzilla and Facebook mail notifications to read the full text.
- Reads weather forecasts polled from Environment Canada web site.
- Reads git and SVN project commit messages (first line and branch/tag updates).
- Battery, network, and temperature status reporting while the laptop running the client is charging or discharging its battery.
- Time service (announces time each minute, useful as an alarm clock when combined with a scheduled change in laptop speaker volume).
- Flexible selection of messages to speak and not speak (by source or content, with support for "quiet" and "noisy" modes).
- Reads local and international news headlines and alerts supplied via RSS feeds, email, and Twitter.
Studied the internal implementation details of several open-source products:
- C++ compilers (GCC)
- OpenEmbedded embedded system cross-compile toolchain
- Debian dpkg and Red Hat rpm packaging tools
- Cryptography (SSL, GnuPG, CIPE, OpenVPN, Bruce Schneier's crypto-related books and articles)
- Database systems (PostgreSQL, MySQL, Berkeley DB)
- Device driver implementation (Linux IDE, SCSI, FM radio, video capture, USB host controller devices)
- Image manipulation (Gimp, ImageMagick)
- P2P distribution and anonymity protection software (BitTorrent, gtk-gnutella, TOR, Freenet)
- Scripting language interpreters (Perl, Tcl/Tk)
- GUI toolkits (Qt, Tcl/Tk)
- Spam filtering (SpamAssassin, DSPAM, CRM114, Razor, DCC, Paul Graham's spam-related articles)
- Video Capture (xawtv, BTTV, mplayer, mencoder, ffmpeg)
Developed a cluster application which searches a significant fraction of Usenet binary newsgroups and extracts files from them. It tracked an estimated 8 billion article headers and used 11 CPU's on 8 machines for searching them. PostgreSQL was used to coordinate CPU usage and content fetching across the cluster. Perl was used for most of the implementation.
Maintain own Internet servers (WWW, SMTP, spam filtering, DNS services, VPN, mobile access, QoS and traffic throttling)
Developed a number of small applications designed for web browsers embedded in cell phones
Attended Linux Symposium technical conference each year since 2000
Wrote Linux device driver for Aztech FM radio ISA card.
Frequent contributor to various technical interest groups and mailing lists on the Internet.
Implemented power-saving features (hard disk spin-down, monitor and printer power-off) in Microware OS-9 running on the Tandy Color Computer III by reverse-engineering and modifying the operating system binary code, designing power control hardware, and building it into the system motherboard.
Volunteer Audio/Visual technician (stage lighting and sound) at Gloucester High School.
Cycling, photography, science, web comics, cat maintenance.