Terminating the device / fdconfig.sys process crashes the system

[ecm-pushbx]

By loading lDebug as a device driver I inspected the system state during device init. It turns out that the kernel sets up an init PSP at segment 60h. This process is self-owned, but its Parent Return Address / int 22h vector appears to be uninitialised:

 &; Welcome to dev mode lDebug
 -r psp .
 PSP 0060
 -r parent .
 PARENT 0060
 -r pra .
 PRA 00D91289
 -u ptr pra l 1
 00D9:1289 CF                iret
 -

The same iret is used as the handler for eg int 2Dh. When the kernel returns from a termination, it will branch to the PRA with the parent's last int 21h stack, which generally will not contain a valid far return address for this iret to use.

I fixed my application to not try to terminate the init process in https://hg.pushbx.org/ecm/ldebug/rev/5740dcb40620 However, I think the kernel should handle its init process being terminated. Control-C and Critical Error Abort could possibly terminate the init process, too.