thanxx

maybe the reason is some compiler only see /hal/rtl8822b/hal8822b_fw.h but didn't see hal/rtl8822b/hal8822b_fw.c
so , the code like this in hal8822b_fw.h will become empty, that's why firmware load failed
extern u8 array_mp_8822b_fw_ap[106848]; extern u32 array_length_mp_8822b_fw_ap; extern u8 array_mp_8822b_fw_nic[161240]; extern u32 array_length_mp_8822b_fw_nic; extern u8 array_mp_8822b_fw_wowlan[103328]; extern u32 array_length_mp_8822b_fw_wowlan;  
to slove this ,  just copy hex fiirmware part from hal8822b_fw.c to  hal8822b_fw.h, detail in this commit.
https://github.com/ChalesYu/rtl8822bs-aml/commit/27fef585225a52913b2936f91abf36859ec20a43

As is stated here: https://forum.armbian.com/topic/16407-please-read-first
it shouldn't be an expectation that wifi is going to work with armbian on TV boxes.  I have about 8 boxes now and wifi doesn't work on any of them.  While there are exceptions, in general if you limit your expectations to using wired ethernet you can do some amazing things with these boxes.  Since you didn't even mention which box you are interested in, I can't guess if wifi has a remote possibility of working for you, but my guess is not.
 
There are only a couple of people currently engaged in volunteering their time to respond to users in the TV box forums.  So I choose to focus my limited resources on helping users who have a reasonable chance of success (i.e. their expectations are appropriate).  Otherwise I could spend all my time trying to help one user try to get wifi working on one poorly supported TV box type and likely be unsuccessful in the end.
 

blind@TX3X3:~$ free
              total        used        free      shared  buff/cache   available
Mem:        3684488      859436     2103944       24008      721108     2643560
Swap:       1842240           0     1842240
blind@TX3X3:~$
 
This is on a TX3 with s905x3 using meson-sm1-sei610.dtb
 
And on a H96 Max with s905x2 using meson-g12a-u200.dtb:
 
blind@H96MaxX2:~$ free
              total        used        free      shared  buff/cache   available
Mem:        3365644      216796     1203640       21244     1945208     2966404
Swap:       1682820           0     1682820
blind@H96MaxX2:~$

the legacy u-boot in those boxes is usually allocating away quite a bit of memory which you'll have to live with or your can try chainloading a mainline u-boot (which is what the u-boot.ext display hack is doing - on boxes where this is used there should be more memory available on average i guess)
 
best wishes - hexdump