OS_Hardware 4 (changes)
Showing changes from revision #0 to #1:
Added | Removed | Changed
Hardware Abstraction Layer
» Other documentation
» OS_Hardware
» OS_Hardware 4
OS_Hardware 4
(SWI &7A)
| Entry | |
|---|---|
| R0 | Bits 0-15 = type to match |
| Bits 16-31 = maximum major version number to match | |
| R1 | 0 to start an enumeration, else preserved from last call |
| R8 | 4 |
| Exit | |
|---|---|
| R1 | -1 if there are no (more) devices of this type |
| R2 | Pointer to device descriptor (undefined if R1 = -1) |
| - | Other registers preserved |
Use
Enumerates the device list, searching for devices of a particular type.
Notes
Devices will be returned in the opposite order to the order they were registered. Use OS_Hardware 5 if you want the devices to be returned in the same order as the order they were registered.
Prior to RISC OS 5.19, this SWI has a bug which can lead to a crash if it encounters a HAL device of the correct type but with a version number newer than that indicated in R0.
See also
Social
Follow us on
and
and
ROOL Store
Buy RISC OS Open merchandise here, including SD cards for Raspberry Pi and more.