[Oberon] Creating SD card image - RISC.img and ORG/ORP

Paul Onyschuk ptmelville at gmail.com
Tue Apr 15 11:59:04 CEST 2014

On Mon, 14 Apr 2014 18:37:23 +0100
"Paul Reed" <paulreed at paddedcell.com> wrote:

> Yes, self-hosting would be much better than the ugly cross-tools I'm
> using at the moment; as time permits...  One of the more important
> aspects of self-hosting is being able to test the new configuration
> before committing to it.  And bear in mind, we are using the real
> hardware.

I used wrong wording, but same method should apply to real hardware and
emulator.  About testing new configuration (which I guess is rebooting
system) beside shuffling SD cards I can think of only one method of
recovery, when something goes wrong: multiboot.  Choosing which
bootloader to user (new/old) seems like only solution... or I'm wrong
and missing something? 

> Notice that the image doesn't have to be big, see the patch to the
> emulator I included in the Windows package on projectoberon.com - if
> it recognises the image file as an Oberon filesystem (beginning with
> FileDir.DirMark) then it virtualises the first 80002H 512-byte
> sectors, which as you quite rightly say don't need to be accessed if
> you're just going to be in emulation.

That is nice feature.  I have seen commit in upstream repository (patch
was pulled by Peter), but I didn't know what it does and how you can
use it.  Now you can get very small image using dd (since I know exact

$ dd if=RISC.img of=SMALL.img bs=512 skip=524290
$ du -ah SMALL.img
496K    SMALL.img

And new image works just fine under emulator.

Paul Onyschuk

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