Ok, now I seemed to got somewhere about the BDF files. The header of BDF files QCA-ATH10K-BOARD is added by qca-swiss-army-knife. And looks like we have to create a json file -- board.json to repack the BDF files to the one usable for OpenWRT [1].
And according to a partial boot log of the stock firmware [2], to make the 5GHz WiFi work, the stock firmware loaded the file QCA9888/hw.2/boardData_2_0_QCA9888_5G_Y9690.bin as its BDF file. For the 2.4GHz part, we know that it is working so far through the log so we will choose to ignore it
for now. Maybe more investigations could be made in the future.
So maybe just repack the BDF file and place it somewhere correct [3], and it will work like a charm? But unfortunately, I don't have a RBR40 for a test now, and my mental status don't allowed me to work on more deeply in it nowadays.
More things to do in the near future:
- Get a full boot log from the stock firmware (use
dmesg > dmesg.logthrough telnet and tftp to transfer it to local) to investigate what was loaded during the boot of the stock firmware. - Build a working BDF file and give it a try.
- See if there is anything changed and if anything not working as expected.
- Maybe we will add the BDF data for the IPQ4019 module of RBR40. The 2.4GHz part is working now, but it is likely that IPQ4019 also plays a role in RBR40's radio, and a BDF file is also needed as the LBR20 [4].
Maybe those references mentioned about will help someone of us:
- How to create a working BDF file: HowTo create ipq40xx BDF files - For Developers - OpenWrt Forum
- Partial boot log of RBR40, BBS is in Chinese but auto translation works well: ath10k驱动的问题 求解惑-OPENWRT专版-恩山无线论坛
- Instructions about how to test a custom BDF file without recompiling the whole firmware: openwrt/package/firmware/ipq-wifi/Makefile at main · openwrt/openwrt · GitHub
- The commited BDF data of LBR20, also see the commit log for the example json file: firmware_qca-wireless/board-netgear_lbr20.qca4019 at main · openwrt/firmware_qca-wireless · GitHub