[ASUS Zenfone 5 (2018)] Unable to boot v300.f/g

[AndyCGYan]

Device: ASUS Zenfone 5 (2018)
Treble status: Yes, non-SaR A-only, native
Stock Android version: 8 (VNDK 26) or 9 (VNDK 28)

Neither versions of stock base would boot v300.f/g. Stock 8 base does a splash loop, while 9 base reboots after splash into the bootloader.
In both cases, after rebooting into TWRP to check, pstore and last_kmsg are absent.
Tried changing fstab to use EXT4 data (ASUS likes F2FS), no change.
Android 10 GSIs boot normally.

[AndyCGYan]

After some difficulty in building kernel, I finally enabled pstore and got some ramoops - see if it's of any use?
pstore.zip

[phhusson]

I attach here for the reference the logs of a device that succeeds to boot a-only (Moto E5, vndk 26, arm32)

logs.txt

What I see as difference is:

[    6.118942] (CPU:5-pid:1:init)audit: type=1400 audit(9876167.109:9): avc:  denied  { create } for  pid=1 comm="init" name="system_ext" scontext=u:r:init:s0 tcontext=u:object_r:system_file:s0 tclass=lnk_file permissive=0
[    6.118988] (CPU:5-pid:1:init)init: Command 'symlink /system/system_ext /system_ext' action=early-fs (/system/etc/init/apex-setup.rc:18) took 0ms and failed: symlink() failed: Permission denied

so add a allow init system_file:lnk_file create_file_perms; in device/phh/treble/sepolicy/init.te and try again

[AndyCGYan]

@phhusson I don't have an AOSP workspace though, and according to others' reports, only AOSP boots on A-only so far. Can I modify this on-device myself, or get a test build from you?

[phhusson]

https://treble.phh.me/s-zf5.img.xz

[AndyCGYan]

Yes that's it, booted! It lags compared to Q, but that's not the concern here.
Please push the fix (if it doesn't impact other devices that is); I'll close this issue now.