Category: Software Debug and Trace – Intel

You can always count on Larry Traylor to crank out useful new content for engineers. This time, heโ€™s updated our Application Note on UEFI Debugging using SourcePoint on Intel Platforms.
In my last article, I outlined a short embedded JTAG-based โ€˜Cโ€™ routine to dump machine check errors in the event of a system crash or hang. In todayโ€™s blog, I look at this in the larger context of diagnosing the root cause of system wedges, and what embedded ITP techniques can be used to gather as much forensics data as possible.
ASSET implements in-situ diagnostics via direct support of the x86 JTAG-based run-control API down on the target. The run-control API are synonymous with lower-level Intel In-Target Probe (ITP) procedures. What follows is a sample โ€˜Cโ€™ routine written to dump the contents of the machine check registers, in the event of a system wedge (for example, a three-strike event).
System Management Mode (SMM) is an x86 operating mode in which all normal execution, including the operatingย system, is suspended. SMM is of interest to cybersecurity specialists (black hat and white hat) because it can also be abused to run high-privilegedย rootkits. This week, I decided to use SourcePoint to explore some of its mysteries.
Moving run-control (Intel In-Target Probe, or ITP) down into the service processor on an x86 design results in a screamingly fast, scalable implementation of at-scale debug. This article contains some timing benchmarks of our embedded solution versus alternatives. The results are nothing short of astonishing.
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