Rob Landley, Programmer

SUMMARY:

Linux developer and trainer with speaking, writing, and project management skills.

Programming languages include C, Bash, Python, Java, and Lua. Areas of expertise include embedded optimization, debugging, cross compiling, system integration, networking, kernel driver development, SMP/threading, hardware bringup. I wrote and maintain the "toybox" package providing Android's standard posix command line utilities, and the "mkroot" cross-compiling build environment. I've also worked as a college instructor, columnist, and convention organizer.

PROGRAMMING WORK EXPERIENCE:

• 2022-2023  Position: Toybox maintainer sponsored by Google.
• Project: Toybox maintainer, full time. Improve and maintain AOSP hermetic build capability, work towards making Android self-hosting.
• Toybox (https://landley.net/toybox) is the BSD-licensed package providing Android's command line utilities (ls, ps, sed, find...) which I wrote from scratch starting in 2006 after handing off BusyBox maintainership. Android adopted it as their command line in 2015, in the Android 6.0 "Marshmallow" release.


• 2019-2022  Position: Linux developer for Core Semiconductor (acquired se-instruments.com).
• Project: J-core BSP maintainer, based on toybox and mkroot. Performed board bringup for new development boards, created documentation and marketing strategy, handled escalated customer support requests.
• Project: ICE-40 GPS platform, integrated J-core and GPS correlator ported from Xilinx Spartan 6 LX45 to ICE-40 FPGA (https://github.com/j-core/j-core-ice40), ported driver software from Linux to bare metal (48k SRAM). Helped design new sattelite downlink protocol for data transmission in partnership with SpaceChain using this hardware as receiver.
• Project: plug-and-play telecommuting (VPN adapter), added USB 2.0 CDC-ECM ethernet support to J-core SOC (VHDL modified from existing CDC-ACM implementation), wrote Linux driver, integrated into USB-powered WireGuard gateway system.
• Project: openroad/openlane toolchain, ported Google's SKY130 ASIC Verilog toolchain from "magic" docker image to build/run in a vanilla debootstrap chroot (https://github.com/j-core/openlane-vhdl-build), added basic VHDL support, various fixes to produce J-core ASIC mask file.
• Project: Battery management system, new battery management system and enclosure for 52 Lithium Iron Phosphate prismatic cells. J1 microcontroller reading voltage+thermal sensors to control bypass transistors and report status, J2 Linux system to control charge/discharge.


• 2018-2019  Position: Linux developer for Johnson Controls.
• Project: Linux conversion of N40 platform, provided OS image to transplant .NET building climate control app (Metasys) from WinCE to Linux (Buildroot with Mono) on 20 year old sh4 hardware (200 mhz, 128m ram, 128m NOR flash). Modified kernel, bootloader, and userspace, coordinated with hardware engineers and Mono contractor in Germany. Achieved realtime performance requirements (4ms driver response, 15ms userspace) from heavily threaded (>80) mono app designed to busy-wait poll under WinCE. Provided Linux expertise to a previously Windows-only development group converting to Linux-only going forward.
• Project: Convert N50 and newer platforms to Linux. Participated in Metasys Linux bringup and optimization team for newer x86 (Atom) and ARM (v7 Smarc) hardware using Wind River Yocto build system.


• 2014-2017  Position: Linux developer for se-instruments.com.
• Project: Board Support Packages for synchrophasor product, using nommu sh2-compatible clean room VHDL SOC developed in house and open sourced on j-core.org. Worked with hardware teams in Tokyo and Ontario. Ported existing Linux kernel patches from 3.4 to 4.x. Maintained three BSP versions: 1) inherited uclinux+code sourcery BSP build (reproduced toolchains from source using buildroot, audited project licenses, updated/migrated package versions), 2) new binflt+uClibc version based on Aboriginal Linux (added target support to existing toolchains, added nommu support to toybox to replace busybox, and worked with musl-libc maintainer to add nommu support to replace uClibc), 3) new fdpic+musl version based on mkroot and musl-cross-make.
• Project: open source community manager. Created and ran nommu.org and j-core.org websites and mailing lists. Found and trained new upstream linux-sh architecture maintainer. Documented hardware and software build processes for j-core FPGA development (VHDL toolchain setup, bitstream build, j-core C/C++ toolchain build, root filesystem build, kernel build, board installation and bringup) for both internal engineers and open source community. Presented and ran tables at Cool Chips, Linux Jamboree, Linuxcon Japan, LF Embedded Linux Conference, Texas Linuxfest, and Smart Energy Week. Created project public roadmap.
• Project: GPS driver. Implemented hard realtime software correlator to parse raw antenna data (compatible with hardware correlators in product board), perform sattelite signal acquisition, doppler and code phase tracking, bit edge detection, subframe recognition, and parity checking/stripping to produce rtklib-compatible input data frames. Replaced rtklib with homegrown frame parser and Newton-Rhapson Method position calculation with fixed point math library. Debugged and optimized realtime constraints to eliminate dropped periods, and diagnosed multiple clock skew/wrap sources in input data. End goal was tracking GPS time with nanosecond accuracy via phase locked loop correcting a local thermally stabilized clock.


• 2013-2014  Position: Linux build engineer for pace.com.
• Project: Maintained Exodus build system for mips and arm based DSL routers. Inherited a combination of buildroot, Broadcom BSP, and a collection of locally developed and vendor code building with Autoconf, packaged up by shell scripts and all building in an x86-64 Fedora chroot. Separated layers, cleaned up and sped up build, upgraded package versions (including migration to new buildroot version), helped migrate products off of older build systems, implemented new factory install image. Participated in project planning for sitewide perforce to git migration.


• 2013  Position: Linux kernel developer for Cray.
• Project: Direct Attached Lustre service nodes exporting a Lustre 2.4 filesystem within Cray supercomputers. Ported and brought up Centos 6.3 and 6.4 on Cray blade hardware. Extracted and ported "Cray Linux Environment" patches from SLES11sp2 to Centos. Provided design input to "IMPS" (Image Management and Provisioning System). Backported v9fs driver (9p2000.L network filesystem, used with "diod" server) from 3.4-vanilla to 2.6.32-centos kernel. Converted Linux initramfs to tmpfs, removed perl from Linux kernel base build requirements (reimplementing perl scripts in C and shell), and submitted both patchsets upstream into vanilla Linux kernel.


• 2011-2012  Position: Linux kernel developer for Polycom.
• Project: Board bringup for "Hawking Saturn" 3-display room teleconference system. Adapted TI ARM Linux branch to hardware (three TI "netra" Cortex A9 SOC, each running android clustering across PCIe and internal gigabit LAN, plus two FPGAs, audio/video I/O, USB3, i2c, etc). Diagnosed hardware issues, fixed gigabit ethernet and USB3 drivers, automated regression test suite for manufacturing, ported drivers between Linux versions, some driver design work, addressed USB and u-boot issues on Mars and HDX boards, helped co-workers debug issues with Android (Gingerbread and Ice Cream Sandwich).
• Project: Board bringup for "Hawking Mars" single display desktop teleconference system, also Netra based. Wrote Power On Self Test code in MLO/u-boot and Linux initramfs. Debugged physical memory layout issues.
• Project: Early bringup for "Hawking Millennium" 360 degree panoramic webcam. Initial hardware check, adapted Linux board layout to hardware (pre-device tree kernel version: worked out configuration, added i2c tables, built Linux From Scratch root filesystem, etc). Worked with hardware devs to identify places the wires didn't go through.
• Other duties as assigned. Debugged customer issues on existing HDX teleconference systems (PowerPC running realtime preempt branch of vanilla Linux). Advised on git/gerrit deployment. Knowledge transfer between departing/arriving co-workers (learned audio subsystem to hand it off, learned DVT build system to hand it off, etc).


• 2011  Position: Linux kernel developer for Parallels.
• Project: Linux Containers. Added container support to network filesystems in Linux kernel (CIFS, NFSv3, 9P), debuged and documented containers userspace tools at lxc.sourceforge.net, traveled to Moscow to liase with OpenVZ developers, ran booth at Scale with OpenVZ maintainer.


• 2010  Position: Linux developer for Qualcomm.
• Project: Port Linux to the Hexagon processor (QDSP6). Debugged kernel and toolchain, bootstraped Gentoo userspace, upstreamed patches to kernel.org and elsewhere. Ran training sessions.


• 2009  Position: Co-owner of Impact Linux LLC.
• Project: Rockwell Collins contract. Diagnose causes of memory exhaustion in an embedded ARM entertainment system. Create diagnostic tools, create documentation about Linux VM subsystem, deliver tutorial session.
• Project: Cisco/Linksys contract. Prototyped new embedded build system for Cisco/Linksys (based on Aboriginal Linux and Gentoo From Scratch). Performed competitive analysis of OpenWRT. Upgraded existing build systems (Bruschetta/Prosciutto, derived from Broadcom BSP) for WRT610n (mips router) and MediaHub (ARM NAS, replaced with PPC version during development). Ported uClibc++ to Crosstool-NG, debugged a home automation server, proposed transcoding strategy, diagnosed RAID/partitioning race condition, etc.


• 2008  Position: Linux Consultant for Oxford Consulting.
• Project: "Scorpion" Embedded Linux C++ programmer for Ion Geophysical Services. Maintenance and upgrades on SMP Linux server software controlling seismic data acquisition network, consisting of thousands of sensors connected via a proprietary bus. This server software collated and processed shockwave (dynamite) data in real-time to visualize underground geology and find oil.
• Project: ARM fax machine Embedded Linux C programmer for Silicon Labs, working on a new fax machine running ARM Linux. Optimized build environment, converted Python prototype to C, attended lots of design meetings.


• 2007  Position: Fellowship from the Linux Foundation
  • Project: Linux Kernel Documentation. Six month fellowship to create and maintain a central kernel documentation website, improve and maintain existing documentation and related tools, and write new documentation. Started "http://kernel.org/doc" directory (see source control repository at "http://landley.net/hg/kdocs", and May-Oct 2007 in the mailing list archive at "http://marc.info/?l=linux-doc").
  
  
• 2006-2007  Position: Embedded Linux Developer for TimeSys
  • Project: "BusyBox" 50% of work week spent maintaining BusyBox.
  • Project: "TimeSys LinuxLink" General embedded Linux development. Acted as domain expert in uClibc and initramfs, worked on cross-compilers and system integration, wrote test software, helped design new build system, spoke at CELF and OLS, answered customer questions, wrote documentation, added Mercurial support to source control system, did Linux kernel development, created a minicom replacement to improve boardfarm automation, etc.
  
  
• 2005  Position: Programmer for Giganews
  • Project: "GCF support". Implemented (in Perl) a dozen test cases for GCF (usenet NNTP forwarding software). Wrote (in C) a statistical usenet spam filtering plugin for GCF.
  
  
• 2004-2005  Position: Consultant at Dell
  • Project: "Rogers" Hardware diagnostic software for SCSI/SAS RAID. Implemented a C++ plugin library according to Dell's existing design, for marshalling data between device firmware (third party binary) and various user interfaces (web based, command line, and standalone Java application).
  
  
• 2003-2004  (Consulting work still under NDA).
  
  
• 2001-2002  Position: Head programmer for WebOffice
  • Project: "iLand gateway" A single box firewall and fileserver for small offices. Web-GUI administration (through Apache with Python CGI), Virtual Private Network (DNAT+SSH+netcat), Network Attached Storage (Samba and custom file transfer CGI), DHCP, Bind, PostgreSQL, root partition on loopback mounted zisofs allowing "firmware upgrade" (whole OS upgraded by replacing GPG signed file). Based on a custom "Linux from Scratch" system with the 2.4 kernel. Designed, implemented, documented, and created manufacturing process for this project.
  
  
• 2000  Position: Head of Linux Development for BOXX Technologies, a high-end graphics/video hardware start-up.
  • Responsibilities: Supervised two people, system configuration/tuning/testing, some software development (C and Java), design of new release management process, customer support/firefighting. Convinced Boxx to reconsider exclusive relationship with Intel and try AMD Athlon, resulting in Boxx and Tyan co-designing the first dual Athlon motherboard (OEMed as Tyan Thunder).
  
  
• 1999  Position: Consultant with Enscicon at Trilogy for IBM.
  • Project: "Order Processing and Forwarding", Java based client/server project connecting IBM's sales and shipping SQL/MQSeries databases. Deployed on AIX and NT.
  
  
• 1998  Position: Contract programmer for Alternative Resources Corporation.
  • Project: 6 month contract at IBM to resume work on "Feature Install" (see 1995) to support several new OS/2 products.
  
  
• 1998  Position: Head programmer for Quest Math & Science Multimedia.
  • Project: "Interactive Diagrams", a series of 45 Java applets for a Pre-calculus tutorial on a CD bundled with a McGraw-Hill textbook.
  
  
• 1995-1997  Position: Full-time development programmer at IBM.
  
  • Project: "JavaOS Application Bringup", debugging JavaOS on Power PC and Intel clients, ensuring compatability with multiple third party java applications.
  • Project: "IBM Software Choice", for purchasing and installing IBM's OS/2 software via the World Wide Web (using Feature Install engine controlled via Netscape plugins).
  • Project: "Feature Install", 32 bit Corba compliant OS/2 install, uninstall, and system inventory software used to install "Falcon" (OS/2 for Power PC) and "Merlin" (OS/2 Warp 4.0).

OPEN SOURCE PROGRAMMING PROJECTS:

• toybox - Created and maintaind Posix/Linux command line implementation which replaced Android's Toolbox in Marshmallow. Toybox now provides most Android command line utilities. See "http://landley.net/toybox/about.html" for details. Registered toybox's "Zero Clause BSD" license (SPDX: 0BSD) and defended it from proposed OSI changes (including securing permission from original BSD maintainer Kirk McKusick to call it a BSD license), then helped get 0BSD recognized by Github's "choose a license".

• mkroot - Created a cross-compiling build system (in less than 500 lines of bash) to bootstrap a reproducible/hermetic target build environment which can natively build and regression test target packages under an emulator (QEMU) on x86, arm, mips, powerpc, sh4, m68k, etc. See "https://github.com/landley/mkroot" for details.

• busybox - Inherited from Erik Andersen, maintained versions 1.01 to 1.2.2. Starting in 2003, extended busybox to fully replace the corresponding GNU tools in a development environment (Aboriginal Linux), and for SUSv3 compliance. Wrote new versions of sort, sed, dmesg, halt, count, losetup, mdev, mkswap, mount, netcat, poweroff, reboot, seq, switch_root, umount... Re-implemented Julian Seward's bunzip2 algorithm to compile to less than 7k and run 10% faster. Wrote new test suite, documented standards compliance with SUSv3. Handed off to Denys Vlasenko in 2007 but continued to contribute for years afterwards (new patch, nbd-client, vi serial fixes, etc).

• Aboriginal Linux - Tiny self-hosting Linux system built from just 7 packages (busybox, uClibc, linux, gcc, binutils, make, and bash) and capable of rebuilding itself under itself from source code. Supported x86, x86_64, arm, mips, powerpc, sh4, and sparc targets (providing QEMU packaging and launch scripts for each). See "http://landley.net/aboriginal/about.html" for details. Replaced by mkroot (above) in 2017.

NON-PROGRAMMING WORK EXPERIENCE:

• Adjunct faculty member at Austin Community College (1998-2000), teaching "Intro to Java", "Unix Operating System I", and "Multiuser Operating Systems".
• Stock market investment columnist for The Motley Fool at www.fool.com from 1998-2000.
• Convention Organizer: Penguicon and Linucon. Co-founded Penguicon in Michigan in 2003 (still going, see www.penguicon.org), founded and chaired Linucon (a 501c3 non-profit) in October, 2004.
• Technical Editor for the "The Art of Unix Programming", by Eric Raymond, published 2003.
• Linux kernel Documentation maintainer (2012-2014). Wrote the standard documentation on several topics (most notably initramfs). See also "http://landley.net/writing/".
• Ran tutorial sessions ("Populating Initramfs with BusyBox and uClibc" and "Introduction to cross-compiling") at Ottawa Linux Symposium in 2006 and 2007. Presented paper "Where Linux Kernel Documentation Hides" and hosted Linux Compiler BOF in 2008.
• Ohio LinuxFest presentation: Developing for non-x86 targets using QEMU.
• Additional presentations at Flourish 2010/2016, CELF/ELC 2010/2013/2015/2017, Ohio Linuxfest 2008/2013, Tokyo Linuxcon 2015, linuxconf.au 2016, and so on.

FORMAL EDUCATION:

• 1997-1998, 2003-2004 - Enrolled at the University of Texas at Austin, as a graduate student in Computer Science. (Withdrew due to work commitments both times.)
• 1992-1995 - Bachelor's degree from Rutgers University (Camden, NJ). GPA 3.419, Majors in Computer Science and General Science, minors in Math & English.