Dieses Jahr fand das Easterhegg wieder in Hamburg statt.

Die Slides zu dem von mir gehaltenen Talk/Workshop gibts nun hier für alle, die es interessiert

Slides

Chaos, Easterhegg, OSDev, presentation, slides

I needed a virtualized Mac OS. I want to know how a special EFI extension works which permanently changes the harddisk. I don’t want to do this on my real machine. I would have to reboot it several times and perhaps loose all my data on my HDD if something goes wrong while I’m experimenting which this extension. Also live debugging would be next to impossible.

Luckily, VMware and VirtualBox are able to virtualize Apple’s Mac OS X Server. His holy Steveness decided to allow virtualization only for the Server version of Mac OS. But there is help, so I “fixed” the DVD to be able to boot a Mac OS X 10.6.3 retail DVD in VMware.

Unfortunately VMware then told me that the CPU was halted by the guest operating system. This happens if a kernel issues a “hlt” statement on all currently active cores without interrupts enabled to wake up the CPU later. This is bad because the whole operating system is trapped in this state. But why did this happen with OS X? (weiterlesen…)

10.6.3, 10.6.6, assembler, cpu, gdb, instruction, intel, Mac OS, patch, patching, x86, x86_64

A while ago, I wrote some demo code to demonstrate various things you need to do to write your own operating system.
In May 2010 I held a lecture and workshop about this code and the concepts at SigInt conference in Cologne, Germany.

I just thought that this code may be interesting to other people who did not attend this conference. (weiterlesen…)

code, demo, Development, interrupts, low level, OSDev, pic, pit, sigint, x86

Sometimes, even if you don’t want to install a pirated Windows version, you may want to dump and modify the BIOS of a computer.
Especially if you are developing some kind of an ACPI subsystem for your own small operating system kernel.

Doing this with real hardware is kinda risky and complex.
But what about virtual machines like VMware? They have a BIOS, but how can we get our hands on it? (weiterlesen…)

BIOS, custom, dumping, extracting, MacOS, OS, OSDev, VMware

Mein momentanes Interessenfeld bezieht sich ja sehr stark auf alles, was mit System- und Hardwarenaher Programmierung zu tun hat.
Da ich auf der Zugfahrt zum 26c3 nicht besonders viel zu tun hatte und die AMD und Intel Dokumentationen auf meinem Rechner hatte, habe ich mal angefangen mich um die Virtualisierungsfunktionen, die diese beiden Hersteller da so in ihre Prozessoren verpflanzen, zu kümmern. (weiterlesen…)

Development, OS, OSDev, Virtualisierung