Last update for today... I compiled a kernel with earlyprintk (not set by default, and I think I lost it somehow when I messed around with kernelconfigs...) So it panics quite early with:   bootargs: earlyprintk initcall_debug console=ttyS0,115200n1 root=/dev/mmcblk0p1 rw rootfstype=ext4 rootwait coherent_pool=4M audit=0 Uncompressing Linux... done, booting the kernel. [ 0.000000] Booting Linux on physical CPU 0x0 [ 0.000000] Linux version 4.14.43-mt7623n (root@Buildmach