Re: Importing LibC Functionality

[Matthieu Lemerre]

address@hidden writes:

Hi,

> I'm new to GNU/Hurd on L4 (and in general), and I plan to implement a device
> driver framework so that real system usability can start to occur while other
> things are improved by other developers.  I'm considering the deva/fabrica and
> antrik proposals and don't currently have my own proposal or a design plan.
>
> However, I was wondering how difficult it is to import libc functionality into
> GNU/Hurd?  For example, let's say I didn't have "fread(3)", I'd have to import
> that into GNU/Hurd's libc for my use.  Also, I assume porting libc
> functionality from GNU/Hurd on Mach would be the best option?
>
> Thanks so much in advance,
> William (AKA Mike) Grim

This is great. You may want to check out the fabrica module on cvs
(cvs -z3 -d:ext:address@hidden:/cvsroot/hurd co fabrica),
which already implements part of it. In particuliar, there are already
libc functions ported from libc (maybe it's not complete, in which
case you could take the one in the hurd-l4 module).

But I doubt you want to use fread or such high level operations in the
device driver framework; the tasks in the device driver framework
(device drivers, bus drivers, and others) should communicate with
regular RPCs, and tasks outside the device driver framework would
communicate with deva using RPCs like "open", "read", "write"
(replacing the corresponding UNIX system calls). Well, unless you want
to implement antrik's proposal, in which case I can't help you.

So I think most of the libc parts you want are for string operations;
for threading, you have libpthread (I have seen there was a libfthread
in the fabrica module, maybe this is lightweight threads? and so maybe
you should use this instead.)

Thanks,
Matthieu