Rocky Linux 9 & HP Elitebook 8470p: Wi-Fi problems reconciled

Annoyingly, the Rocky 9 installer ISO didn't come with the Wi-Fi drivers for my HP Elitebook 8470p. The laptop seems to have a “Intel Corporation Centrino Ultimate-N 6300 (rev 3e)” PCIe Wi-Fi adapter, which worked fine out-of-the-box on Ubuntu and every other distro I tried on it, but not this one.

I diagnosed this via dmesg:

[  108.888963] Intel(R) Wireless WiFi driver for Linux
[  108.889046] iwlwifi 0000:25:00.0: enabling device (0000 -> 0002)
[  108.889135] iwlwifi 0000:25:00.0: can't disable ASPM; OS doesn't have ASPM control
[  108.937577] iwlwifi 0000:25:00.0: Direct firmware load for iwlwifi-6000-6.ucode failed with error -2
[  108.969279] iwlwifi 0000:25:00.0: Direct firmware load for iwlwifi-6000-5.ucode failed with error -2
[  108.969412] iwlwifi 0000:25:00.0: Direct firmware load for iwlwifi-6000-4.ucode failed with error -2
[  108.969462] iwlwifi 0000:25:00.0: no suitable firmware found!
[  108.969495] iwlwifi 0000:25:00.0: minimum version required: iwlwifi-6000-4
[  108.969530] iwlwifi 0000:25:00.0: maximum version supported: iwlwifi-6000-6
[  108.969577] iwlwifi 0000:25:00.0: check git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git

The “solution” was to do this (on a live system which can't persist any changes between reboots and doesn't have easy access to install packages):

1. Mount an existing, functioning Linux installation at /mnt (or download the RPM package at the below link)
2. Copy iwlwifi-6000-4.ucode from $source/lib/firmware to /lib/firmware
3. modprobe -r iwlwifi; modprobe iwlwifi

Disturbingly, this seems to be a regression policy decision. They have the firmware available for RL8—iwl6000-firmware—only it's vanished from the RL9 repos.

If you want to ignore this omen (don't do it!) and continue installing RL9 anyway, you can just save that RPM file somewhere and then install it again on the system after it reboots into the installed RL9. Unlike a live system, you don't need to do the above mumbo-jumbo; you only need to install that package and then reboot.

If you don't have an (additional) flash drive on hand, and just using Ethernet isn't an option, I recommend alt-tabbing out of the installer while it's running to smuggle the file into the in-progress system, specifically /mnt/sysroot/root, so you can access it easily in any event.