[GTALUG] UEFI + ACPI on Raspberry Pi: thoughts for a Lightning talk

[D. Hugh Redelmeier]

Note: I'm winging this.  I'd welcome contributions and comments from 
other.

Nice news I heard at BSDCan (thanks Chris!):
UEFI + ACPI for Raspberry Pi 4
<https://rpi4-uefi.dev/>

Why is this important?

The ARM ecosystem needs a universal environment to make OS distros
universal.

Almost every ARM system ("platform") is different, and this means that
every Linux distro that supports it must be customized for that platform.
(Contrast that with Linux Distros for the PC.)

This works for the Raspberry Pi since that Platform is common enough.

It works for Android (a Linux distro) because each SoC maker does the
first half of the work and each phone maker finishes the job.  That's
just the cost of entry to the game.

This is also why Android Phones lose software support so quickly: the
SoC maker has no interest in long life, and neither do most phone
makers.

What is the solution?

- the SoC maker has to want to do this (only they have specs for the
  device)  (perhaps forced by Google?)

- we need a consensus of the ABI for what ABI all firmware will provide
  OSes.

Examples from previous platforms:

- "BIOS" in CP/M (late 1970s)

- "BIOS" in IBM PC

- eventually: UEFI, APM, ACPI in successors to PC

In ARM:

- uboot [not really standardized]

- "Device Tree" [not really standardized]

- UEFI + ACPI [fat!]

Unfortunately, consensus forming is messy and doesn't always happen.