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OS_Memory 9
Programmer's Reference Manuals
» Part 15 – SWI Calls
» OS
» OS_Memory
» OS_Memory 9
OS_Memory 9
(SWI &68)
| Entry | |
|---|---|
| R0 | 9, all flag bits reserved |
| R1 | Controller number |
| Exit | |
|---|---|
| R0 | Preserved |
| R1 | Controller base logical address, or 0 if not present |
Use
The purpose of this call is to check for the presence of a given controller and return its base logical address if present. The behaviour of this SWI differs slightly between RISC OS 5 and RISC OS Select/Adjust. Under RISC OS 5 the SWI will return an error if the controller number is unrecognised, or 0 if the controller isn’t present. Under RISC OS Select/Adjust the SWI will return an error under both situations. Also under RISC OS Select/Adjust, even if the controller exists there is no guarantee that the memory will have been mapped in by the kernel. Therefore programs should also use OS_Memory 25 where appropriate, in order to allow them to map in the memory themselves.