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HAL_KbdScan
Hardware Abstraction Layer
HAL entry points from RISC OS
» HAL_KbdScan
HAL_KbdScan
(HAL entry #102)
unsigned int HAL_KbdScan(void)
| Entry | |
|---|---|
| - |
| Exit | |
|---|---|
| Bit 0 | Ctrl down (indicating hard reset) |
| Bit 1 | Shift down (indicating reversal of *Configure Boot) |
| Bits 2-3 | Reserved, should be 0 |
| Bit 4 | R down (CMOS reset, auto sync) |
| Bit 5 | T down (CMOS reset, seperate sync) |
| Bit 6 | Delete down (full CMOS reset, auto sync) |
| Bit 7 | Copy/End down (full CMOS reset, seperate sync) |
| Bits 8-29 | Reserved, should be 0 |
| Bit 30 | Keyboard presence detected |
| Bit 31 | Keyboard scan complete |
Use
This is an internal call for OS use only and should not be used by user software.
Called when the Kernel wants to check the results of the keyboard scan so far.
The return value indicates which keys have been detected. Bits must never be reported clear when they have been reported set by a previous call.
The “complete” bit indicates that the HAL is confident that sufficient time has elapsed for the keyboard (if present) to have reported all keypresses.
The Kernel will typically make this call repeatedly until the “complete” bit is set, although the HAL should not rely on this – the Kernel may have its own timeout.