HAL_IRQProperties (changes)

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Hardware Abstraction Layer

HAL entry points from RISC OS

» HAL_IRQProperties

HAL_IRQProperties

(HAL entry #53)

__value_in_regs struct { int irq, fiq; } HAL_IRQProperties(int device)

Use

This is an internal call for OS use only and should not be used by user software.

Returns information about the behaviour of the given interrupt.

The low 16 bits of irq and fiq are bit masks, indicating which core(s) the interrupt can be routed to, and whether it can be routed as an IRQ or FIQ. E.g. a binary value of 11 for irq indicates that the interrupt can be routed as an IRQ to either core 0 or core 1.

The high 16 bits of irq and fiq provide extra flags:

• Bit 31 is set if the interrupt can be assigned to multiple cores at once, clear if it can be assigned to (a maximum of) one core at a time.
• Bit 30 is set if HAL_IRQEnable/HAL_IRQDisable (or FIQ equivalents) will only operate correctly if they are called from a core which the interrupt is currently routed to (e.g. private peripheral interrupts in a GIC). If the bit is clear, the calls will operate from any core, and the interrupt enable state is shared between all cores (e.g. shared peripheral interrupts in a GIC).
• Bits 16-29 are reserved and should be zero.

See also

• HAL_IRQSetCores
• HAL_IRQGetCores

Information source: Kernel.Docs.SMP.IRQ in git