Monthly Archives: March 2020

Running EAGLE 9.6 on Debian 10 (buster)

For some side project I wanted to look at the schematics of the Adafruit PowerBoost 500C, which happened to be made with Autodesk EAGLE.

Having run EAGLE on Debian 9 (stretch) for a while now without great hassle, I did not expect much difficulties, I was wrong. First I downloaded the tarball from their download site. Don’t worry, there’s still the “free” version for hobbyists, however it’s not Free Software, but precompiled binaries for amd64 architecture, better than nothing.

After extracting, I tried to start it like this and got the first error:

There’s no verbose or debug option. And according to the comments on the blog post “How to Install Autodesk EAGLE On Windows, Mac and Linux” the problem also affects other users. I vaguely remembered somewhere deep in the back of my head, I already had this problem some time ago on another machine, and tried something not obvious at all. My system locale is German, looked like this before:

As you can see, no English locale, so I added one. On Debian you do it like this. Result below:

This seems like a typical “works on my machine” problem from an US developer, huh? Next try starting eagle, you’ll see the locale problem is gone, the next error appears:

That’s the problem if you don’t build from source against the libraries of the system. In that case EAGLE ships a shared object libxcb-dri3.so.0, which itself is linked against the libxcb.so.1 from my host system, and those don’t play well together. I found a solution to that in a forum thread “Can’t run EAGLE on Debian 10 (testing)” and it is using the ld_preload trick:

This works. Hallelujah.

Performance Analysis on Embedded Linux with perf and hotspot

This is about profiling your applications on your embedded Linux target or let’s say finding the spots of high CPU usage, which is a common concern in practice. For an extensive overview see Linux Performance by Brendan Gregg. We will focus on viewing flame graphs with a tool called hotspot here, based on performance data recorded with perf. This proved to be helpful enough to solve most of the performance issues I had lately.

Installing the Tools

We have two sides here: the embedded Linux target and your Linux workstation host. For your computer you need to install hotspot. In Debian it is available from version 10 (buster). You can build from source of course, I did that with Debian 9 (stretch) a while ago. IIRC there are instructions for that upstream. Or you build it from the deb-src package from Debian unstable (sid) by following this BuildingTutorial.1

The embedded target part needs basically two parts. You have to set some options in the kernel config and you need the userland tool perf. For ptxdist here’s what I did:

  • Add -fno-omit-frame-pointer to global CFLAGS and CXXFLAGS
  • Enable PTXCONF_KERNEL_TOOL_PERF

Note: I had to update my kernel from v4.9 to v4.14, otherwise I got build errors when building perf.

Configuring the Kernel

I won’t quote the whole kernel config here, but I have a diff on what I had to set to make perf record useful things. These options are probably important, at least I had those on in my debug sessions (others might also be needed):

  • CONFIG_KALLSYMS
  • CONFIG_PERF_EVENTS
  • CONFIG_UPROBES
  • CONFIG_STACKTRACE
  • CONFIG_FTRACE

Using it

For embedded use, I basically followed the instructions of upstream hotspot. You might however want to dive a little into the options of perf, because it is a very powerful tool. What I did to record on the target was basically this to get samples from my daemon application mydaemon for 30 seconds:

This can produce quite a lot of data, so use it with short times first to not fill your filesystem. Luckily I had enough space on the flash memory of the embedded target available. Then just follow what the hotspot README says: copy the file and your kernel symbols to your host and call hotspot with the right options to your sysroot. This was the call I used (from a subfolder of my ptxdist BSP, where I copied those files to):

Happy performance analysing!

  1. I did not test that with hotspot []