[Qemu-devel] Modding an Arch

["William Pearson" <wil.pearson@gmail.com>]

I'm hoping to do some research on a slightly odd form of resource
allocation in an arch. Not sure which yet, hoping for some advise. My
only real world assembler practice has been 68K (a while ago), but I
have coded in my own assembler before on another homebrew very limited
odd VM.

I'm going to be changing these things, whilst keeping the rest constant,

 - how IRQs are assigned to handlers
 - how memory is protected
 - boot sequence
 - security levels
 - what the bios does when it finds devices
 - possibly adding a few instructions to the arch to facillitate the above
 - Paging in some fashion (might be removed)

These will be added

 - security in interactions with a special persistant memory (hard
disk alike) which will be what is booted
 - a device handled by the arch (rather than software)

My goal is to get a demo that works up quickly-ish (a year or two
while learning the arch, doing research and writing a very minimal
demo OS probably in asm), but can also be extended nicely into a
proper working system sometime down the line. I don't care about
backwards compatibility. But easy porting tools across would be nice.

So my questions are,

1) Is qemu a sensible thing to do this in.
2) If so which arch should I mod
3) What should I look at apart from stuff referenced in this thread

http://lists.gnu.org/archive/html/qemu-devel/2005-12/msg00157.html

Feel free to message me off-list if you want details of the arch, they
are a bit raw still though, as I'm still in the process of figuring
them out.

 Will Pearson