Actually with PCI chipsets, implementing a generic BusMaster DMA driver
is not too hard, assuming you already have interrupts handled (and you don't want 64bit DMA support)... You just load the parameters for the disk read into the PCI registers, and wait for the completed interrupt. I wrote a diver in assembly language for my own OS project a few years ago.


   Keean.

Iavor Diatchki wrote:

Hello,
There are no storage drivers at the moment.  Actually part of the
motivation for implementing the networking stuff was so that we can
avoid doing that at least for the time being.
-Iavor


On Mon, 21 Mar 2005 01:32:19 -0500 (Eastern Standard Time), S.
Alexander Jacobson <[EMAIL PROTECTED]> wrote:


Very very cool.
Has anyone written any storage drivers?
If there is already TCP, has someone written an iscsi (RFC3720)
driver?

-Alex-


On Mon, 21 Mar 2005, Donald Bruce Stewart wrote:



dons:


alex:


Wow! Did you also implement tcp in Haskell?


On this topic, the following House code looks relevant:
  http://cvs.haskell.org/cgi-bin/cvsweb.cgi/programatica/hOp/kernel/Net/

There's something satsifying about seeing 'instance Functor Packet' in
IPv4.hs ;)



Does hOp or House also have the ability to write to disk?

(With HAppS, I've gotten rid of the AMP part of LAMP, it would be
really cool to get rid of the L as well!)


Sorry! By "We've got a few drivers written in Haskell", I meant
"the Haskell community", not me personally :} You have the hOp and House
developers to thank for this stuff.



On Mon, 21 Mar 2005, Donald Bruce Stewart wrote:



mark:


I was wondering about the possibility of using Haskell for developing
device drivers that would be kernel modules for Linux. If nothing else,
it would be quite an educational experience for me, as I've not yet
experimented with either the Linux kernel or Haskell FFI, nor have I
had to learn how to squeeze much performance out of my Haskell code.

Clearly, this application demands special things from the compiler and
the runtime. But, I'm not exactly sure what, nor how to achieve such
given current compilers. Does anyone have any thoughts?


Well, it would be tricky, but fun!

We've got a few drivers written in Haskell already (but not for Linux,
as far as I know). For example check out the House network stack and
drivers:
 http://cvs.haskell.org/cgi-bin/cvsweb.cgi/programatica/hOp/
and
 
http://cvs.haskell.org/cgi-bin/cvsweb.cgi/programatica/hOp/kernel/Kernel/Driver/NE2000/

So there's heavy use of Data.Bits and Word# types - but nothing that
isn't fairly well established in GHC Haskell, anyway.

Then (for GHC, anyway) you'd have to link the kernel against libHSrts.a,
much
as we do when calling Haskell from other kinds of C apps, which involves
compiling the C app with all the magic flags ghc normally sets up (ghc -v9
main.c is helpful).  Something like: ;)

egcc -v -o a.out -DDONT_WANT_WIN32_DLL_SUPPORT main.o
-L/home/dons/lib/ghc-6.4 -lHStemplate-haskell -lHSCabal -lHSposix
-lHSposix_cbits -lHSlang -lHSmtl -lHShaskell-src -lHSunix -lHSunix_cbits
-lHShi -lHShaskell98 -lHSaltdata -lHSbase -lHSbase_cbits -lHSrts -lm -lgmp
-u GHCziBase_Izh_static_info -u GHCziBase_Czh_static_info -u
GHCziFloat_Fzh_static_info ...

Then, having the kernel start up the Haskell rts (at boot would be
good):
   hs_init(&argc, &argv);
     .. do something in Haskell or C land ...
   hs_exit();

Then you'd could dyn load (via GHC's rts) your Haskell driver into the C
app, and use it, as long as you've got a nice ffi interface to pass
values back and forward.

I'm sure the fun part is in the details ;)

Cheers,
Don
_______________________________________________
Haskell-Cafe mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/haskell-cafe



_______________________________________________
Haskell-Cafe mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/haskell-cafe


______________________________________________________________
S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com
_______________________________________________
Haskell-Cafe mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/haskell-cafe



_______________________________________________
Haskell-Cafe mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/haskell-cafe



_______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe

Reply via email to