UpCall Handler (changes)
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OS SWI Calls
» OS_ChangeEnvironment
» UpCall Handler
UpCall Handler
| Entry | |
|---|---|
| R0 | Reason code |
| R12 | Workspace pointer |
| All other registers dependent on reason code | |
| SVC mode, IRQ+FIQ state undefined | |
Use
Called by the kernel to warn an applications of particular situations.
If the UpCall handler is called and R0 = UpCall_NewApplication (256), all handlers should be restored to their previous values and you should then return to the caller preserving all registers, letting the new application start.
See also
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