[Freemint-list] Falcon + _FPU cookie

[Thorsten Otto]

On Saturday 11 March 2017 15:07:14 Miro Kropáček wrote:

>because 030+ doesn't use the peripheral mode anymore.

Not to access the internal copro. But the memory mapped one is not part of the 
processor, and still accessible even with PAK/3 installed.

> And they are -- I think you've misinterpreted the meaning of "SFP+6888x"

I dont think so:

* The full definition of this cookie (as of now, 5/90) is as follows:
*
* The high word of the _FPU cookie value contains a description of the
* hardware FP support present in the machine.  

* The low bit of the high word is set if and only if there is an SFP004-
* equivalent floating-point peripheral installed.
*
* In addition, the next three bits (at least) describe the presence of
* a 6888x coprocessor: a value of %001 means either 68881 or 68882,
* %010 means 68881 explicitly, %011 means 68882 explicitly, and
* %100 means the 68040's built-in floating-point hardware.
*
* The reason for this scheme is that you may actually have both an
* SFP004-equivalent peripheral installed AND a 6888x coprocessor,
* if (for example) you have upgraded a Mega STe with a 68020 + 68881.
*

>You simply can't have both 030+ style FPU and SFP FPU in the same time.

See above. I think you actually can.