Charlie Jacobsen authored Sep 01, 2015 and Vikram Narayanan committed Oct 26, 2016

Example is in virt/lcd-domains/test-mods/glue-example. It consists
of a fake minix and fake vfs. The original "unmodified" code is
in minix/original/main.c, vfs/original/main.c, and include/vfs.h.
The glue code (written by hand) is in minix/glue and vfs/glue. The
IDL is in idl/.

You can build the fake minix and vfs for isolation or as regular
modules. To build for isolation, run `make menuconfig' and under
Test Modules --> Example Exercising IDL and Glue.

To run minix and vfs in isolation, install the "boot" module,
lcd-test-mod-glue-example-boot.ko. (Its code is under isol-boot/main.c.)

The example will print status messages to the kernel logs so you
can see a trace of the interaction.

A few hacks were necessary to fully exercise all of the code. For example,
the fake vfs is the one that invokes new_file and rm_file, in the middle
of its dispatch loop.

The code for the trampolines in vfs/glue/vfs_caller.{c,lds} is probably
the ugliest part. That required a little bit of trickery and low-level
hacking.