OSDev.org

Hi all

Soon we're going to start seeing hard disks with the "Advanced Format" which depending on the type, will have 4KiB sectors. Have you people seen any proper documentation on how to interact with these drives, or detect what the drive's sector size is?

There is some developer kit thing, bit i have no idea if it costs lots money, or is this stuff written into the latest ATA spec?

thanks
srg

CDs have non-512-byte sectors, SCSI supports non-512-byte sectors, so if you have a SCSI or ATAPI harddisk then it may technically present itself as a 4k device already.

From the specs I have seen, the 4K sectoring is entirely internal and is completely invisible from outside the disk. Externally, the disk still represents itself as an entirely normal 512b sectored disk.

bewing wrote:From the specs I have seen, the 4K sectoring is entirely internal and is completely invisible from outside the disk. Externally, the disk still represents itself as an entirely normal 512b sectored disk.

Ahh that's the 512e (e for emulation version). I was thinking more along the lines of 4kn, which is native 4KB sectors.

http://en.wikipedia.org/wiki/Advanced_Format

Hi,

srg4096 wrote:Soon we're going to start seeing hard disks with the "Advanced Format" which depending on the type, will have 4KiB sectors. Have you people seen any proper documentation on how to interact with these drives, or detect what the drive's sector size is?

There is some developer kit thing, bit i have no idea if it costs lots money, or is this stuff written into the latest ATA spec?

It's in "Information technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)". For the IDENTIFY DEVICE command, see word 106 (Physical sector size / logical sector size), words 117 and 118 (Logical sector size) and word 209 (Alignment of logical blocks within a physical block).


Cheers,

Brendan

Brendan wrote:Hi,

It's in "Information technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)". For the IDENTIFY DEVICE command, see word 106 (Physical sector size / logical sector size), words 117 and 118 (Logical sector size) and word 209 (Alignment of logical blocks within a physical block).


Cheers,

Brendan

Thanks, so it's really not a big issue, just need to ask the drive using already provided commands rather than just assuming 512k sectors. I didn't know if this meant changes to specs, it appears it doesn't.

Thanks!

You shouldn't be assuming 512 byte sectors to begin with, then your code would just keep working as normal... .

srg4096 wrote:Thanks, so it's really not a big issue, just need to ask the drive using already provided commands rather than just assuming 512k sectors.

512 kilobytes?