[openbeos-midi] Re: mpu401 module

  • From: "Philippe Houdoin" <philippe.houdoin@xxxxxxx>
  • To: openbeos-midi@xxxxxxxxxxxxx
  • Date: Fri, 10 Jan 2003 10:09:09 +0100 (added by postmaster@wanadoo.fr)

> > Oh, BTW, somewhere on the road, OBOS midi
> > team will have to rewrite this MPU401 kernel
> > module too. Glup. ;-)
> 
> Why is that=3F It is part of the Sonic Vibes sample code, is it not=3F
> So we can simply use that, or at least work from there. Unless I am
> missing something...

No, it's not part of Sonic Vibes sample code. the midi=5Fdriver.h file 
that 
come with this sample driver is the public API of this kernel module 
called 
"generic/mpu401/v1", which live in the ELF file /boot/beos/system/add-
ons/kernel/generic/mpu401.
This kernel add-on offer generic MPU401 support, thru the API published 
by 
the generic=5Fmpu401=5Fmodule struct in midi=5Fdriver.h.

There is also a second, small, kernel module related to midi, called 
"media/midiparser/v1", which live in /boot/beos/system/add-ons-kernel/
media/midiparser, exporting the midi event parsing API published by the 
midi=5Fparser=5Fmodule=5Finfo struct in midi=5Fdriver.h.
This kernel module seem to be usefull for midi device driver to split 
each midi event from their rx fifo buffers and return only the first 
one in their read() hook (or maybe their B=5FMIDI=5FTIMED=5FREAD support, if 
any).

The source code for both these kernel modules is NOT available, only 
their public API (see midi=5Fdriver.h, thanks sample-code!). So, they 
would have to be rewritten for OBOS R1 too.
The first one is hardware related, and required a good knowledge on how 
MPU401 and compatible chips 
works. If someone could find some official MPU401 spec, or at least a 
well-known open source MPU401 driver, it will help greatly before 
starting to write this mpu401 kernel module.

The second one involve only parsing code, and seems far easer to 
rewrite, based on comment & sample code on how to use it in 
midi=5Fdriver.h.

-Philippe


--
Fortune Cookie Says:

Your fault: core dumped


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