Sept 2020 build doesn't work

There seems to be something wrong with the Sept 2020 prebuilt image, TB-96AIoT-images-npu1.3.2-20200923. It doesn’t appear to boot and the CPU uart output shows the following:

DDR Version V1.04 20191121
LPDDR3
933MHz
BW=32 Col=10 Bk=8 CS0 Row=15 CS=1 Die BW=32 Size=1024MB
out
Bootl Release Time: Dec 9 2019 18:18:13, version: 1.05
chip_id:524b186,0
ChipType = 0x15, 10271
sfc nor id: ff ff ff
sfc_nand_id: ff ff ff
NeedKHz=200KHz,clock=12000KHz
NeedKHz=200KHz,clock=12000KHz
NeedKHz=200KHz,clock=12000KHz
NeedKHz=18000KHz,clock=192000KHz
NeedKHz=48000KHz,clock=192000KHz
mmc2:cmd19,100
SdmmcInit=2 0
BootCapSize=2000
UserCapSize=7456MB
FwPartOffset=2000 , 2000
SdmmcInit=0 NOT PRESENT
StorageInit ok = 20602
SecureMode = 0
Secure read PBA: 0x4
Secure read PBA: 0x404
Secure read PBA: 0x804
Secure read PBA: 0xc04
Secure read PBA: 0x1004
1806 loader need rk sign!
SecureInit ret = -1, SecureMode = 0

Can anyone advise? Thanks.

(By the way, is this another Android build? Looking for a more ‘stock’ linux ideally, e.g. debian or something)

If you need a ‘pure’ GNU/Linux distro, you may want to try building your system from source with buildroot: https://www.96boards.org/documentation/som/tb-96aiot/build/buildroot.md.html

Thanks Loic, that probably is the plan eventually, but was hoping to get it working with the prebuilt first to find my feet so to speak. Haven’t built Linux from source before so I can’t imagine it will go well if I can’t even understand why this one isn’t working :).