So the with the 21.02.release the table of hardware has gotten a lot shorter because of the ar71xx -> ath79 transition. Is it the case that the "missing" targets simply have not yet been tested with the ath79 firmware, or are they known not to work? Should I try to build custom images (for i.e. my Mikrotik routers which were ar71xx) and test them? Is some percentage of the missing hardware expected to "just work" and/or is some percentage expected to definitely not work?
I think especially the mikrotik subtarget hasn't been ported because of some serious outstanding issues.
For the existing subtargets, a port from ar71xx should be easier, but it still needs to be done on a per-device basis.
Before you can test, there needs to be ath79 firmware for ex-ar71xx devices.
If there is not ath79 image available, the device needs to be ported from ar71xx to ath79.
See Porting guide ar71xx to ath79? as a starter.
For the Mikrotik devices I think the biggest problem is the NAND driver. Something like it doesn't support BAD blocks. Then there is the fact that the older units use YAFFS to boot from and YAFFS isn't mainlined and probably never will be, even after several attempts. I own several Mikrotik devices and I am not happy support was dropped. I tried getting a developer to help, but they backed out. I am willing to pay a openwrt developer to port these devices. No one is interested.
if you want contract work you probably need to ask third party consultants that have OpenWrt experience.
OpenWrt core developers are mostly volunteers.
Also be prepared to pay handsomely, as developer time is expensive and if your fix requires more than a few days it may easily become unaffordable.
also I think @pprindeville might be interested
I have to hand:
1 cap lite
3 map lite
7 hap lite tc
2 hap ac lite
1 ltap mini
2 sxt lite
1 sxt ac lite
I'm happy to test with any of the above if anyone needs me to
These topics might be of interest:
I am willing to send them to the person who does the porting.
The problem with Mikrotik ath79 devices is YAFFS, as mentioned above, and the fix is not trivial.
Most recent discussion is available in my pull request for RB2011: https://github.com/openwrt/openwrt/pull/3729
In short, we have several options: restore YAFFS support in kernel (breaks with each kernel update and requires active maintenance), implement YAFFS support in userspace (requires coding a program that would detect bad blocks and write to NAND correctly) or porting U-Boot bootloader (needs to be adapted for each model separately).
Getting YAFFS into the mainline kernel has been tried and failed. The last attempt I could find was 2010. I think this is the best option personally.
A userspace version, I can't comment on this one. I don't have the necessary knowledge.
Replacing uboot is also an option that would work. This was done for the RB750gr3, https://openwrt.org/toh/mikrotik/mikrotik_rb750gr3_obsolete. The problem would come from how to do the update without a chip programmer. If an update can be done without a chip programmer then I think this becomes the best option. A one time upgrade and done. No active maintenance needed.