A fast and easily customised operating system for ARM devices

OS_Word

Entry
R0	Reason code
All other registers dependent on reason code

Exit
R0	Preserved
All other registers dependent on reason code

The purpose of this call is to provide a number of general operations.

The action performed depends on the reason code value in R0.

#	Hex #	Action
0	&00	Read line from input stream
1	&01	Read system clock
2	&02	Write system clock
3	&03	Read interval timer
4	&04	Write interval timer
9	&09	Read pixel logical colour
10	&0A	Read a character definition
11	&0B	Read palette
12	&0C	Write palette
13	&0D	Read current and last graphics cursors
14	&0E	Read CMOS clock
15	&0F	Write CMOS clock
21	&15	Define pointer and mouse parameters
22	&16	Write screen base address

Revised on November 13, 2017 00:38:41 by Alan Robertson (52) (49.192.18.196)

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