FreeBSD

These are untested builds of FreeBSD-10, created with Crochet Raspberry-Pi BeagleBoard Soekris

If you happen to have had an Apple][, you might be interested in retrieving your data from old DOS 3.3 floppies.  Or maybe you’re just interested in retrocomputing and downloaded some floppies at Apple2Online.  In my case, I had an ulterior motive.  I’ve been learning about FreeBSD device drivers and was wondering how difficult it…

Crochet-BSD is a github project which supports building FreeBSD disk images for various platforms such a RaspberryPi, BeagleBoard and others.  I had a Soekris 4501 laying around, so I decided to extend Crochet to build images for it. So, firstly, I needed a kernel.  Building the kernel config for Soekris is explained pretty well here….

I’ve been learning about FreeBSD kernel development, and discovering that, not surprisingly, it’s very, very slow to compile on a Raspberry Pi.  So, I decided to figure out how to compile the Pi kernel on a nice fast AMD-64. Firstly, get the kernel sources to a subdirectory under a non-root user profile: mkdir fbsd cd…

How the FDT works In specific, I’m looking at this file bcm2835.dtsi which contains the hardware definitions for the BCM2835, the SOC which powers a Raspberry Pi. Primarily, i’m interested in how to read it.   To really make sense of this, you should have this pdf at hand; it’s the hardware manual for BCM2835.  If…

It’s been a goal of mine for a while to understand how FreeBSD device drivers work.  So, firstly I wrote a simple module; it’s here.  The next step is to write the skeleton of a device driver.  That is, a device driver that does nothing.  The resulting source code is here. The Makefile is very…

In preparation for writing a device driver, I thought I would firstly write a module.  The resulting source code is here.   Firstly the Makefile: SRCS+=bus_if.h device_if.h examplemodule.c KMOD=examplemodule .include <bsd.kmod.mk> The first line defines the sources.   examplemodule.c is my module source.  I needed to include bus_if.h and device_if.h since I’m writing my module…

Building a FreeBSD kernel for Beaglebone is not terribly difficult.  Firstly, you need the FreeBSD-Current sources: svn co http://svn0.us-east.freebsd.org/base/head /src/FreeBSD/ Next, build the cross-development tools for FreeBSD: cd /src/FreeBSD/head make XDEV=arm XDEV_ARCH=armv6 xdev Then get Crochet-FreeBSD.  This is by far the easiest way to build a FreeBSD kernel for Beaglebone git clone git://github.com/kientzle/crochet-freebsd.git Once you…

I recently got a Beaglebone Black.   I was very excited; it’s similar to a Pi, but has 60 GPIO ports! Getting a serial console up on it was not quite a simple as I thought, since the BeagleBone uses FTDI.  Following the instructions here I installed the OS X serial driver for FTDI.   After plugging…

The FDT file for Raspberry Pi, declares UART.  I’ve had quite a bit of trouble understanding how declaring a uart in the FDT results in /dev/tty0 and /dev/cuau0 appearing in /dev/ Here are the relevant lines from the FDT: uart0: uart0 { compatible = “broadcom,bcm2835-uart”, “broadcom,bcm2708-uart”, “arm,pl011”, “arm,primecell”; reg = <0x201000 0x1000>; interrupts = <65>;…