Bug 273705

Summary: Archaic aspects of device.hints cause boot failure with some modern hardware
Product: Base System Reporter: Vincent Milum Jr <freebsd>
Component: confAssignee: Warner Losh <imp>
Status: Open ---    
Severity: Affects Some People CC: grahamperrin, imp, lwhsu, michael.osipov
Priority: ---    
Version: 14.0-STABLE   
Hardware: amd64   
OS: Any   
See Also: https://reviews.freebsd.org/D41549

Description Vincent Milum Jr 2023-09-10 16:24:10 UTC 
/boot/device.hints by default contains information for scanning very old legacy hardware, such as floppy disk controllers and the ISA bus. One of these items is also the old AT keyboard interface via the ISA bus.

On modern hardware such as the Steam Deck, these legacy interfaces no longer exist, preventing FreeBSD from booting properly. Commenting the lines out in the file allows it to boot properly.

However, it is only a matter of time until more and more systems drop these legacy interfaces, the Steam Deck is just one of, if not the first device that we've seen this on.

At least on AMD64, I think it may be time to remove these references to ISA bus scanning, as its causing real issues with the boot process.

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And before anyone jumps in with some harsh comment about testing FreeBSD on the Steam Deck because it is a "game console" - the hardware inside is essentially an AMD APU based laptop. It acts and functions almost identically to any other laptop device. The only major difference is the physical form factor. The changes seen on this device to remove legacy interfaces from the APU most likely will also hit mainline APUs before long, so in my opinion it is better to tackle this now rather than later.

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Reference:
https://wiki.freebsd.org/Laptops/Steam_Deck
Comment 1 Graham Perrin 2023-09-16 15:55:18 UTC 
(In reply to Vincent Milum Jr from comment #0)

> ⋯ such as floppy disk controllers and ⋯

Partly related: 

⚙ D41549 Deprecate fdc and fdformat for 15
Comment 2 Warner Losh freebsd_committer freebsd_triage 2023-09-16 16:30:12 UTC 
What specifically would you remove?
And what, specifically, causes what kinds of problems?
These are effectively all unused, so this bug surprises me a lot.
Comment 3 Warner Losh freebsd_committer freebsd_triage 2023-09-16 16:31:24 UTC 
This ISA bus is still in all amd64 machines. It's bedrock to the platform and cannot be disabled, ever. The ISA BUS slots are long gone, but the things that make up the ISA bus are still there...
Comment 4 Mark Linimon freebsd_committer freebsd_triage 2024-01-13 23:58:02 UTC 
^Triage: bugmeister guesses this problem is still in 14-STABLE.  (14-CURRENT is now out of support).

To submitter: can you provide more details about which specific things prevent booting?
Comment 5 Warner Losh freebsd_committer freebsd_triage 2024-01-14 00:01:49 UTC 
Oh. I know this issue. 
I need to look at some assumptions that ive made to date and at what we support. Vincent and i have tLked offline