HAL TODO (changes)

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Hardware Abstraction Layer

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List of broken functionality

This list contains functionality that is 100% broken or may break at a future date due to hidden limitations.

• RISCOS_AccessPhysicalAddress(nothing) and RISCOS_ReleasePhysicalAddress, despite being specified in documentation and implemented, are not exported by the kernel source code in Kernel.hdr.OSEntries.

List of nonsensical functionality

This list contains functionality that doesn’t make sense, from the perspective of creating a clean API.

• RISCOS_AddDevice can theoretically fail (if a device with that address is already registered and something prevents it from being removed), but no return value is given to indicate this failure. However this may be a non-issue since you’re just trying to add a device which is already added, so the device will be there whatever the outcome.
• HAL_IRQClear has a dual role of servicing devices and servicing the interrupt controller (main problem being that the extra overhead that will slow down interrupt handling a bit).
• The HALDeviceAudio_AudC’s CustomDMAEnable() function returns a RISC OS error block rather than an enumerated value which gets mapped to a RISC OS error, like the IIC return values.

List of ambiguous functionality

This list contains functionality that is ambiguous in specification or implementation.

• HAL_VideoSetPowerSave and HAL_VideoVetMode are ambiguous in specification.
• HAL_VideoOutputFormat has ambiguous return codes.
• HAL_IRQEnable/HAL_FIQEnable have ambiguous behaviour if an attempt is made to enable both IRQ and FIQ interrupts for the same device.
• HALDeviceVideo_VDU, HALDeviceSysPeri_IntC and HALDeviceComms_UART have no information available about their specification.

List of documentation shortfalls

This list contains HAL topics yet to be described.

• Update source code to point to wiki as source for documentation
• Scan source code and determine actual implemented functionality of all HAL functions
• Update wiki with documentation from external sources
  • Iyonix website
  • StrongHelp manuals
• Document other HAL related areas
  • HALLib
  • HALTester