Thursday, 4 February 2010

Oops

Ok, so my MMU code was all broken. First I was just using the wrong number of bits in the L2 pages - x86 uses 4K pages with 1K entries, but ARM is only 1K pages with 256 entries, and I can't add up simple 2 digit numbers ... But even that didn't help ... many iterations and hours later ... ahh, I forgot to map the serial port - I was only mapping 16MB of i/o and there's another 1MB to map. Grr. Added that to the Haiku code and suddenly turning on the MMU 'works'.

Well it wasn't all wasted effort, I have a better understanding of the various permission and cache bits now. Better than nothing at least.

So ... ta-da ...



Actually it's nothing to be too excited about - that's all it does, and it's been hacked in very messily.

1 comment:

Alex said...

ha, at least ARM can get the boot screen. PowerPC just gets a Kernel with the air bags deployed :/

good work!