On 3/16/24 08:52, ofthecentury wrote:
I boot with 'boot -c' and then enter 'disable mei' and then 'quit'. Pcidump still shows Intel MEI, just as it does when booting with default config. I don't think anything changed.
In this case, correct. As was already pointed out -- devices exist or don't -- but that's a hw config that the OS doesn't usually have a lot of control over. All the OS can do is connect a driver or not. config or ukc only disables OS support for something. pcidump will show you what HW the OS knows exists, and on modern machines, that's going to be a pretty complete list.
But UKC doesn't complain when I disable mei, so I know it knows 'mei' and disables it.
this assumption is not correct: ukc> disable nothing # invalid device -- no response ukc> disable ep # valid device -- response! 110 ep* disabled 111 ep* disabled You can easily verify this with a known good device and a bogus name (like my 'nothing' above).
But how would I know it does disable it? Also, 'boot -c' accumulates what changes I do. How does one reset changes to go back to vanilla kernel?
Again, an incorrect assumption. boot -c does NOT retain changes between boots. UKC> is after the kernel is loaded but before the kernel is fully running. While in ukc>, the kernel doesn't really have an ability to write to disk, as it hasn't been fully started yet. IF you want to make changes to disk, use "config -ef" from the booted system, then write your changes to disk. Then you can either use config -ef to re-enable a device, or just copy over an unmodified kernel. Be aware that altering the kernel binary will "break" the Kernal Address Re-Linking (KARL). There are fixes for this, HOWEVER, I'm not sure what your goals are here in tweaking your kernel like this, but I'm guessing breaking KARL isn't your biggest problem you are about to create for yourself. This probably isn't something you want to be doing. Nick.
