Dsp56k.xdd
From SpareMiNT Wiki
The device is for Falcon030, obviously, references to the F030 DSP host interface (I mean absolute addresses) are hard-compiled, the driver actually only checks the Cookie Jar to see if it is running on a Falcon (strictly speaking: if the Cookie _SND indicates DSP). I have no clue, whether the DSP cards for Milan/Hades are compatible at the hardware registers level with the Falcon.
There are some cosmetic changes relative to Linux version. Perhaps the most important one is changed definition for the (user program visible) struct dsp56k_host_flags. The members of this struct were orginally defined as type int, which probably means they are 32-bit integers. Since MiNT device drivers have to be compiled with -mshort flag, this changes the definition of type int into a 16-bit integer.
So I explicitly casted the struct members to ushort (not ulong, coz I think they're in fact 16 bits or even 8). Please let me know, if you think it would cause problems - I'll cast them to ulongs then.
Also all other variables have now explicit sizes (there is not a single int left). Since the device driver vector table is defined as array of pointers to functions, which can have int arguments, casting all ints to shorts generates some spurious warnings about "initialization from incompatible pointer type". Ignore them.
Hints
- when the DSP is locked by TOS, Fopen() to the /dev/dsp56k returns EBUSY (-2 or so)
- Fopen(), when succeeds, automatically does Dsp_Lock()
- Fclose() automatically does Dsp_Unlock()
- calling Pterm() with having an open file descriptor on the /dev/dsp56k causes DSP reset
