Showing posts with label 2.6 kernel. Show all posts
Showing posts with label 2.6 kernel. Show all posts

20080218

MaverickCrunch / EABI Toolchain, Kernel, and Sysroot




Hi everyone,

I just announced a somewhat lengthy HowTo with information on building a fully compliant kernel, root filesystem, and toolchain for use with the ep93xx series of SOC's. This is really mainly addressed at Gentoo Linux users due to the build system in place.

GentooWiki:Gentoo_for_the_TS72xx_SBC_(Full_Distro)

The next few steps are getting a package manager working, a commissioning station, and also a database for storing client/host keys.

20070808

Montréal: Hacking the Kernel

So I've been back in Canada for slightly longer than a week and I'm working full time for Visible Assets until the end of September.

I've decided to postpone my flight back to Hamburg until the end of September so that I can spend a bit more time with friends and also get a bit more done for work.

Right now, I'm sitting in Montréal at Erin's place. It's been nice to be back - actually, I think I'm suffering less culture shock in Montréal than I would be in Toronto. To tell you the truth, I think mon fronçais went straight down the garbage chute since October, as if German had totally displaced it in my brain. I really think that I'm going to have to work hard at it when I get back to Canada full time, and it would be nice to work towards some sort of bilingual certification or something.

A good friend of mine from the undergrad days, Ed Cote, is in Montréal at a conference presenting some of the work he's done at Queen's, in his master's program. He just finished this past semester (I'm jealous!). Today we're going to be meeting up for a 'cinque à sept', which basically means to have a few drinks at the end of the work day. I'm looking forward to getting out on a patio and having a couple of cold ones, especially in this heat!

For the next month and a half I will be porting much of the code that I've done in user space to kernel space - well, as much as possible, i suppose. Things that I won't be able to convert to kernel space are services and so on.

Particularly, one thing that I'm working on at the moment is a virtual block device that represents tracked / timed connections to the blaster device. What's particularly strange about this, is that I'm hijacking a serial device from within kernel space, albeit with a removeable module.

So far, it's going pretty well and I even have my module initializing the uart, but I've encountered a couple of segfaults. Luckily, I'm testing all of this using Qemu ;-)

Update (2007-08-09): I've managed to fix all segfault issues with serial hijacking by exporting a function init_tty_dev, which is just a wrapper for init_dev, in drivers/char/tty_io.c . Now the uart_driver->tty_driver->tty_struct array will contain a non-NULL pointer to a tty_struct which init_dev initializes. This must always be released with release_tty_dev( struct tty_struct * tty, int idx ) when the module unloads in order to return the refcount.

20070517

Things on the To-Do List for work

I have to push a new filesystem and kernel, as well as installation instructions for work.

Currently, we're using the TS-7xxx boards, with a Cirrus EP93xx / ARM 920T processor, for our embedded devices. The trouble is, that the boards ship with a non-standard 2.4 kernel and the bloated glibc library. I've successfully compiled and installed the 2.6.20.6 linux kernel as well as a uClibc userland for the boards, but now I'm in the process of working out bugs and installing other software that is necessary for the basic functionality of our boards.

To-Do:
  • Make nfs-mounting work on the boards (recompile uClibc with full RPC, and then busybox)
  • Build OpenVPN
  • Build an FTP service
  • Build JamVM
  • Copy over the GNU Classpath that we have
  • Build Avahi
  • (etc, etc)
You may have guessed that this isn't such a small job. Anyway, I'm going to try to do quite a bit of it today.

Ciao!