On 28.06.2014 20:37, Bruno Wolff III wrote:
If netconsole is built as a module, you can't use it to capture
before the module gets loaded. Rebuilding Fedora srpms (to get Fedora
patches) takes pretty long, which makes testing slow.
I have something particular I am testing now (probably a nouveau related
crash) that crashes for netconsole gets loaded (though I tried to add
it to the initramfs to get it loaded fairly early). I am not sure if it
will be early enough even if it is built in. I won't know until sometime
tomorrow. But if it does get loaded early enough to handle video card
related stuff, it seems like it be worth having built into debug kernels.
This is how it can be done;
When the boot reaches any of the multi-user.target or graphical.target
probably network is already set up so you just have to:
- check whether [tgt-port] is opened.
# modprobe [-v] netconsole
# modprobe [-v] nouveau
At the "tgt" with:
# nc -l -u [tgt-port]
after '4.' you'll see something like:
[ monotonic timestamps] [drm] Initialized drm 1.1.0 20060810
[ monotonic timestamps] fb: switching to nouveaufb from VESA VGA
[ monotonic timestamps] Console: switching to colour dummy device 80x25
[ monotonic timestamps] nouveau [ DEVICE][0000:02:00.0] BOOT0 : ...
There may be additional steps related to the specific set up, however it is more or less