Adding a new syscall to gnumach

[Joan Lledó]

Hi Hurd,

In my work to extend the memory proxies implementation, I'm considering 
adding a new syscall which receives a memory object and returns whether 
is it a proxy or not. I need something like that from the arbiter to 
properly set ranges when creating a new proxy.

What are the steps to add a new syscall?, is there any docs? I wrote the 
function and declared its prototype in mach4.defs, but it's not enough.

Thanks