Re: misc/60956: ramdisk-cgdroot.fs seems to check for /libdata/firmware/ in the ram disk rather than the mounted cgdroot

["Taylor R Campbell via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR misc/60956; it has been noted by GNATS.

From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
To: "David H. Gutteridge" <david%gutteridge.ca@localhost>
Cc: Ellie <el%horse64.org@localhost>, Martin Husemann <martin%duskware.de@localhost>,
	gnats-bugs%NetBSD.org@localhost, netbsd-bugs%NetBSD.org@localhost
Subject: Re: misc/60956: ramdisk-cgdroot.fs seems to check for /libdata/firmware/ in the ram disk rather than the mounted cgdroot
Date: Tue, 3 Nov 2026 14:26:54 +0000

 > Date: Mon, 02 Nov 2026 17:07:06 -0500
 > From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
 > 
 > I haven't tried this myself (I don't use this particular setup), but I
 > believe it may be possible instead to add the /altroot path to the
 > firmware loading path, e.g.:
 > 
 > hw.firmware.path=/altroot/libdata/firmware:/altroot/usr/libdata/firmware
 > 
 > ... or such in your sysctl.conf.
 
 This helps with drivers that load firmware at time of first use by
 userland, but not with drivers that load firmware at config_mountroot
 time.
 
 For those drivers, we need to either:
 
 (a) bake the firmware images into cgdroot.fs;
 
 (b) teach the bootloader to gather firmware images from another source
     than the root file system like it does for the kernel, modules,
     and cgdroot.fs itself; or
 
 (c) find a way to defer the firmware loading in these drivers until
     the `real' root has been mounted -- which the kernel doesn't have
     a concept of.
 
 And, if there are any drivers that only load firmware at time of first
 use (not sure offhand which, if any, do this), it would be nice for
 them to not get out of sync between the boot medium, cgdroot.fs, and
 the `real' root.
 
 It should not be a matter of asking users to manually assemble their
 own custom cgdroot.fs from sets or a custom build -- we should have a
 systematic way to handle this.