TODO

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| TODO |
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Orcus:
	* LCD functions - yuv
	* F200 touchscreen
	* Interrupts - could be handy for timer, also for audio buffers running low? what about DMA transfers finishing?
	
remove orcus_delay entirely

Order to work on:
* Interrupts:
   > Need a way of setting the master swi/irq/fiq functions, as well as exception handlers
   > Provide a default IRQ and FIQ implementation where user can register a callback for a specific type of interrupt
   > Configure whether something is an IRQ or FIQ interrupt
   > Function for triggering SWI - EABI calls SWI 0 with the number in R7 due to caching
   > Would like the ability to interrupt on...
      - v/hsync
      - DMA transfer complete
      - timer
      - buttons
      - 2d accelerator finished
      - the 920/940 interchange registers
* I2C (looks very simple to implement so a quick win before getting into something involved)
* Touchscreen