Enumerating disks and controllers at a BIOS level

[andyp73]

Hello (michaln),

As part of the BIOS extension I have to enumerate all of the disk controllers in the system (both PATA and SATA) to work out what drives are attached to them.

I thought that enumerating the controllers would be easy using Int 1Ah function B103h (find device by class code) and looking for class codes 0101 (IDE), 010600 (SATA) and 010601 (AHCI). It turns out that this BIOS function needs both the class code, subclass code and programming interface which is problematical on the PATA controllers as it changes depending on whether controllers are in legacy or native mode. Is there a way to get the BIOS function to ignore the PI register without me having to implement a replacement?

With the VirtualBox AHCI controller, how does a disk attached to SATA Port 0 appear to the controller? Is it accessible through the Primary Command Block Base Address (equivalent to primary master) or do I find the base address for the command block for sending commands to this disk at an alternate location?

Thanks,

Andy.

[mpack]

This is hardly a "Using VirtualBox" question. Moving to "VirtualBox API" forum, for want of anything better.

[michaln]

If you are interested in bootable drives then using EDD might be better. Also, what about bootable USB drives and similar?

With the VBox AHCI emulation, there is no IDE compatibility.

[andyp73]

Thanks for the heads up. Looks like I can get all the information I need from the various int 13h calls and saves me having to poke around finding all of the disks and probing them myself!

Andy.