Category: Software Debug and Trace

In Episode 41, Hacking the Linux Kernel, Part 2, I successfully hacked the Linux kernel, both on a native Linux partition, and within a Ubuntu VM on VirtualBox, by using the general directions within the Linux Newbies First Kernel Patch tutorial. This week, I worked towards hacking the Linux kernel using a Yocto-based qemux86 on VirtualBox, as a final step towards actually hacking the kernel on my MinnowBoard.
Rejoice, Linux kernel newbies. Last week, I hacked an Ethernet driver in the Linux kernel, but the hack didn’t work; it turns out that the driver I chose isn’t used in my native Linux image on my PC. This week, I tackled the problem again, with success! And if I can do it, you can, too.
It’s been a few months since I did any work with my MinnowBoard; time seems to fly by during the summer. In this episode, I pick up where I left off, doing various Yocto builds as I worked towards source-level debug of the Linux kernel. But, I’m having mysterious build failures, with some of the segmentation fault symptoms I had months ago before I RMA’ed my AMD CPU. Could this be raising its ugly head again?
You can always count on Larry Traylor to crank out useful new content for engineers. This time, he’s updated our Application Note on UEFI Debugging using SourcePoint on Intel Platforms.
In my last article, I outlined a short embedded JTAG-based ‘C’ routine to dump machine check errors in the event of a system crash or hang. In today’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.
System Management Mode (SMM) is an x86 operating mode in which all normal execution, including the operating system, is suspended. SMM is of interest to cybersecurity specialists (black hat and white hat) because it can also be abused to run high-privileged rootkits. This week, I decided to use SourcePoint to explore some of its mysteries.