Considering the original ARM use case was a desktop-computer shaped thing with some degree of expandability, they had to solve the same problems that the PC did in bringup/enumeration/device abstraction. These should be solved problems.
At some point between Archimedes and iPhone, they lost this functionality. I assume there was a moment where they assumed that they were only doing SoCs with fixed peripherals and jettisoned all their knowledge and tooling in the space.
> ...jettisoned all their knowledge and tooling in the space.
ARM made a smart decision not to compete against Intel/AMD at the cutting edge, and instead completely dominated the low-power CPU market.
> These should be solved problems.
They are. The solutions have nothing to do with the ISA. The device discovery functionality you're talking about (ACPI/BIOS/etc) is provided by the motherboard, and (in the case of ACPI) made available to the OS by the bootloader. SoC's don't need sophisticated device discovery.
Considering the original ARM use case was a desktop-computer shaped thing with some degree of expandability, they had to solve the same problems that the PC did in bringup/enumeration/device abstraction. These should be solved problems.
At some point between Archimedes and iPhone, they lost this functionality. I assume there was a moment where they assumed that they were only doing SoCs with fixed peripherals and jettisoned all their knowledge and tooling in the space.