ARM Instruction Set: SWI Instruction

Assembler input:

SWI <SWI number>

Assembler output:

High byte as standard
Bottom three bytes are SWI number (24-bit cardinal)

SWI numbers (24-bit cardinal) are partitioned as follows:

Top nybble  Operating system ID
    	      0  RISC OS
    	      8  RISC iX
Bits 18-19  System software section ID
     	      0  OS
     	      1	 OS extension
     	      2	 Applications
     	      3	 User
Bit 17	    Error action
    	      0  Error generating
    	      1	 Error returning
Bits 6-16   Chunk ID
Bits 0-5    SWI ID within Chunk