When to use Emulation when to use Hardware, when to use Virtual devices.Re: Software Emulator

Ian Stirling openmoko at mauve.plus.com
Mon Mar 5 02:26:35 CET 2007


John Carter wrote:
> If you are working at the Application level, it is _way_ _way_ nicer
> just to work in a Bog Standard Linux Desktop Native
> environment. Everything is _way_ faster, your tools are _way_ better &
> smarter (valgrind, gcov, gprof, gdb, compile,link,d/load,run
> cycle....)

The neo has some really rather odd CPU properties, compared to your 
average PC.
This makes performance optimisation for those who are not utterly 
familiar with the datasheet tricky.
AIUI, there is no emulator that will accurately do timings, so a number 
of things where it would be really nice to minimise CPU - and hence 
battery use in compute intensive apps, are much easier with hardware.
For example, playing with array sizes, memory bandwidth tradeoffs, 
optimiser flags, ...
Some of this can be done with a batch program running service.

Along with the obvious hardware questions which you raise is the most 
fundamental and difficult to solve.
Fake (or real) GPS and GSM are much easier to add to PCs than a 280dpi 
480*640 touchscreen.

I suppose one method of helping this would be something that displays a 
240*320 downscaled image - not quite right sized, but close, and lets 
you select between an image of a stylus, and of a finger as a pointer.
These have configurable random placement errors.






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