Qs about building new kernel

[Osman Eralp]

I'm having difficulties building a kernel that works on the
PandaBoard. Has anyone built a new kernel for the PandaBoard
successfully? If so, can you please answer the following questions?
1. From where did you get the source?
2. Did you build on the PB or cross compile? If you cross compiled,
what tool chain did you use?
3. To get the files onto the SD card, did you use flash-kernel, or did
you just copy uImage to the first partition and the modules to the
second partition?

Thanks!
Osman

[Dave Curtis]

I haven't played with my Panda much, and it's been a while since I was working with the BeagleBoard, but back then I was compiling drivers (not a whole kernel) so have a few somewhat stale bits of input for you.

TI does patches that are in their git repos, and may not yet be upstream, although they do get there eventually. RCN -- Robert Nelson www.rcn-ee.com seems to be a good source for reliable and up to date kernel sources/patches/images. I would start by poking around there to make sure you have the latest TI patches. Replicating RCN's build environment might be a reasonable place to start -- although I don't know what that is or how much effort that is.

Warning: Everything I said is stale information.

-dave

[Osman Eralp]

Thanks for the info. I meant to follow up on my original post. I did
figure out how to compile from scratch a new kernel for the
PandaBoard. I used the ti-omap branch of the Ubuntu tree. I also
managed to apply the real time patches from kernel.org. Using
cyclictest, latentcies are in the 25 us range. I'll post my
instructions on building a real time kernel on the wiki. --Osman

[Dave Curtis]

That's very cool. Having a real-time kernel in the robot will enable lots of good stuff.

-dave

[Wayne C. Gramlich]

All:

I spent a chunk of time with my nephew today working on some
electronics meant to interface with my CNC mill. The mill is
controlled by the EMC2 motion control software. This software
runs under Linux with the RTAI extensions. The EMC2 developers
have really done an excellent job of interfacing to the real
time Linux extensions. If you want to get an idea of how it
all works, I recommend get an EMC2 Live CD and working through
the HAL (Hardware Abstraction Layer) Users Guide. By the time
you are done, you will have a software signal generator and
oscilloscope hooked together. Really cool. I mention this
as to reinforce Osman's efforts to get RT Linux running on
a PandaBoard.

-Wayne