OS_CallASWIR12 (changes)

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Programmer's OS Reference SWI Manuals Calls

» OS_CallASWIR12Part 15 – SWI Calls

OS_CallASWIR12

(SWI &71)

Use

The purpose of this call, is to call a run-time determined SWI.

Notes

This call is identical to OS_CallASWI, except that it uses R12 to specify the target SWI. This may be more convenient in some environments. In particular under APCS-R, R10 is the stack limit pointer, which must be preserved at all times.

If a SWI called using OS_CallASWI were to abort or generate an error the run-time library would usually examine R10 and decide that it had no stack to handle the abort or error. Therefore APCS-R libraries must use OS_CallASWIR12 (R12 being a scratch register under APCS-R).

The CallASWI module provides this functionality for versions of RISC OS 3.70 or earlier.

See also

• OS_BreakPt
• OS_CallASWI
• OS_CallAVector