Selectively making ACHI ports ejectable on MacPro?

[Kuruma]

I have a bit of an interesting challenge... it looks technically feasible, but I have no clue how to begin.

 

Scenario: MacPro systems have an extra two SATA ports underneath their fan casing. NewerTechnology even makes an extender cable that attaches to the motherboard and uses one of the PCI external plates to turn this into an eSATA connection.

 

Problem: Any devices that are connected to this drive port will NOT be ejectable. You canNOT remove the drive or swap it with another unless you want to reboot. Sleeping the system will NOT work around the problem. The system seems to scan the ports only once on startup and after that, they are assumed to be static and unchanging.

 

I've seen that on OSx86 boxes people are having some difficulty occasionally in making their internal SATA drives register as non-ejectable, instead being ejectable.

 

So I want to do that with only two of the ports.

 

XLR8YourMac.com has an article on this:

<http://www.xlr8yourmac.com/feedback/Mac_Pro_Ext_SATA_Case_Kit.html>

 

Specific section of interest:

 

Intel mentions in their developer documentation that:

 

" this may be of some interest for your readers.

From the Intel 631xESB/632xESB I/O Controller Hub data sheet:

"Hot-Plug Operation

Dynamic Hot-Plug (for example, surprise removal) is not supported by the SATA host controller. However, using the PCS register configuration bits and power management flows, a device can be powered down by software, and the port can then be powered off, allowing removal and insertion of a new device. "

 

(I asked if he knew of any way to do that in OS X.)

the SATA controller does support AHCI mode, which enables hot plugging (same as with the raid southbridges ICH6R - ICH8R which support hot plugging with raid drivers from Intel without Intel assuring this).

 

But it does not support AHCI if the PATA port is used as in the Mac Pro. And without AHCI there is no way to do hot plugging.

 

Using a SATA DVD drive may not mean AHCI is used automatically. The controller has to be switched from IDE to AHCI mode. Maybe the Mac Pro does it on startup or some EFI specialist can finds out how to do that.

 

BTW Tiger can handle an ICH8R in AHCI mode on all SATA ports without a problem.

Kind regards,

Martin S. "

 

So, does anybody have a suggestion on how to do this?

[aeonach]

 

 

Would also like to see the answer to this one.