Not sure why I can sometimes edit my previous messages and why sometimes I can't, so I'm just replying to the topic...
I found the answer to #3 in the wiki page for building tcz's so I'm assuming that information is still accurate. I'm able to load my extension now, but I'm running into another issue that I'll need to clean up before I submit the package for inclusion in the repo.
I'd still like answers to my first 2 questions from the previous post. Additionally:
3a) The package I'm building does not include DESTDIR, but it is also an extremely simple Makefile. I just looked at the install target in the Makefile, and used that to figure out where it was putting the files (confusingly, it actually seems to copy the firmware files twice - once explicitly to /lib/firmware and once to ${FIRMWAREDIR}/lib/firmware - but when I manually put them in /usr/local/lib/firmware instead of /lib/firmware it seems to work fine). I manually copied the compiled drivers and firmware into /tmp/wifi-rtw88 (preserving the paths from the install target under that). I'm assuming that should work fine, but I'd like confirmation of that.
3b) submitcq thinks everything is ok other than the license file issue mentioned above. I then test this by copying the tcz file into my tce directory, booting up my USB on my laptop, and then loading the extension. When I do that, though, I get the following output:
tc@box:~$ tce-load -il wifi-rtw88
loading out-of-tree module taints kernel.
rtw88: Unknown symbol ieeee80211_start_tx_ba_cb_irqsafe (err -2)
...
However after that I load wireless-KERNEL.tcz and wifi.tcz, and I'm able to connect to my access point. What do those errors mean, and how do I fix them before submitting?
I'm attaching the makefile from the wireless driver package in case there is anything else in there that I'm missing. The one item from the Makefile that I didn't explicitly handle in my tcz is "depmods -a ${KERNEL}", but since this module doesn't have any dependencies (that I know of) I assumed that step isn't actually necessary. I don't know anything about depmods though, so please correct me if I'm wrong.