jk: blog

I often have folks asking how the text & video consoles work on OpenPOWER machines. Here's a bit of a rundown on how it's implemented, and what may seem a little different from x86 platforms that you may already be used to.

Last week, Michael and I were discussing long-term Linux support for OpenPOWER platforms, particularly the concern about testing for non-IBM hardware. We'd like to ensure that the increasing range of OpenPOWER platforms, from different manufacturers, don't lose compatibility with the upstream Linux kernel.

Since we're using buildroot for the OpenPower firmware build infrastructure, it's relatively straightforward to generate a standalone toolchain to build add-ons to the petitboot environment. This toolchain will allow you to cross-compile from your build host to an OpenPower host running the petitboot environment.

As of commit 2aff5ba6 in the op-build tree, we're able to easily replace the kernel in an OpenPower firmware image.

Now that the OpenPower sources are available, it's possible to build custom firmware images for OpenPower machines. Here's a little guide to show how that's done.

I've been working on petitboot's netboot code recently. Here's the lowdown on how it all works.

Want to do a test boot of a powerpc machine, but don't have one handy? The qemu ppc64-softmmu emulator is currently working well with the pseries target, and it's fairly simple to get an emulated machine booting.

Quite a few of the codebases I've worked on have some form of linked list implementation; generally a list node type:

The Ubuntu Developer Summit was held in Copenhagen last week, to discuss plans for the next six-month cycle of Ubuntu. This was the most productive UDS that I've been to — maybe it was the shorter four-day schedule, or the overlap with Linaro Connect, but it sure felt like a whirlwind of activity.

Cross-compile-o-naut wookey has recently posted a set of Debian & Ubuntu packages for an aarch64 (ie, 64-bit ARMv8) cross compiler: