[Rpcemu] RISC OS 5.15 and RPCemu

Peter Howkins rpcemu.howkins at marutan.net
Wed Apr 29 02:37:15 PDT 2009

On Tue, Apr 28, 2009 at 09:07:20PM +0000, Tom Walker wrote:
> The undefined instructions that pop up in at least !Help and !Draw, look to
> be CLZ - an instruction that's in the XScale but not ARM7500. This 
> doesn't appear to be emulated (I haven't poured through the ROS source 
> code to see) so I suspect this would have happened on the A7000 at 
> Wakefield. Did anyone who went happen to notice this?


"The sources have acquired a light sprinkling of ARMv4 instructions like 
UMULL, in SpriteExtend for one, which means they won’t work properly as-is 
on pre-StrongARM machines."

It looks like there's also some ARMv5 in there too as you found. Which is 
something ROOL will have to fix for real hardware.


"Known issues include: CMOS appears to be reset on every boot"

There's the mouse reconfiguration.

It also looks from the commit messages that this has very much been 
developed on an A7000, as such I also wouldn't expect Quadrature mouse 
yet. And it looks to have a fairly hard-coded memory map, which could be 
the 8MB only you found? 

Hope this helps, it seems there's a bit of work on the ROM side to make 
this support more variations of the a7k/riscpc hardware, and to tidy up 
any unsupported instructions.


Peter Howkins
peter.howkins at marutan.net

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