Cannot add services to vndservicemanager

[aleasto]

On a HALIUM device i'm unable to register services to /dev/vndbinder.
My device is a Volla Phone 22, HALIUM 11, running either SailfishOS or Ubuntu Touch

Using the python bindings i can reproduce with this snippet:

import gbinder
serviceManager = gbinder.ServiceManager("/dev/vndbinder")
response = serviceManager.new_local_object("org.foo.bar", lambda x,y,z: print(x,y,z))
serviceManager.add_service_sync("foobar", response)

On my desktop running the vndservicemanager from Waydroid I can register services just fine. But on the Volla Phone 22 using vndservicemanager from Waydroid doesn't help.

[aleasto]

This appears to come down to VNDK vs VNDK-lite.
With full VNDK it expects 'VNDR' in the header

libgbinder/src/gbinder_rpc_protocol.c

Line 191 in 885d27c

gbinder_writer_append_int32(writer, BINDER_SYS_HEADER);

It works with Waydroid on my desktop because Waydroid runs as vndk-lite except on HALIUM