Power Debugging with JTAG - Patrick Titiano & Alexandre Bailon, BAYLIBRE
Channel: The Linux Foundation
Date: 2018-10-25

Power Debugging with JTAG - Patrick Titiano & Alexandre Bailon, BAYLIBRE

Debugging power management issues is traditionally done via the serial console, Android USB/ADB, or SSH eventually. Besides being tedious, it is also intrusive debugging (CPU “regular” execution flow periodically interrupted to log traces over the UART, a rather slow interface with blind windows during CPU power transitions). But there is another option: the JTAG port. Well known for deep kernel debugging, it used to be less popular for power debugging. Well, until now! JTAG port offers the only non-intrusive solution to monitor system activities. Leveraging already-available python libraries, it is now possible to monitor key power indicators (clock rates/states, power states, voltages, bus stats, etc) without altering the use-case power profile, from your host PC.

Motivations, challenges, benefits, and results will be further exposed, including a demo of a “power dashboard” application. 

About Alexandre Bailon
Alexandre Bailon is a co-founder of BayLibre, an embedded Linux consultancy, where he developed USB gadget support for Google’s Project Ara modular phone, and currently implementing power optimization for iMX7ULP SoC. Before co-founding BayLibre, Alex worked at Texas Instruments hacking on the Linux kernel scheduler, memory management and GPU drivers for the OMAP application processor. 

About Patrick Titiano
Patrick Titiano has 18 years of engineering experience in embedded technologies. Patrick spent 9 years at Texas Instruments as an OMAP Power Management Expert (from architecture to use-case power optimization). Patrick also developed embedded diagnostic open source tools (“omapconf”, “cpuloadgen”, “pyacmecapture”) related to power optimization. In 2012, Patrick co-founded Baylibre with ex-TI Linux experts, an Embedded Linux Consulting Firm, to continue sharing its expertise with the Community. More recently, BayLibre was contracted by customers like Google (Patrick leading ProjectAra SW Power Management Team), NXP (Patrick doing iMX8 power optimization), and joined AGL project (focusing on Continuous Integration). Patrick is used to train a wide range of audiences: engineers, customers, sales, marketing.