HPA and DCO on eMMC disk?

Question

I bought a used Tablet (Pokini Tab A8, should be identical with: Aavamobile Inari 8, Fujitsu Stylistic V535, Wortmann TERRA PAD 885 INDUSTRY, Bressner TOUCAN Mobile 8.3", TETRATAB Casepad 8 and TAROX Craftab 8.3") which runs Windows 10 on an Atom CPU. Now I want to ensure that there are no remains of the former user left on the Disk (64 GB eMMC). Usually (regarding PCs) I use UBCD to run HDAT2 to check for HPA and DCO, disable them if present and run DBAN afterwards to erase the HDD. This Tablet seems to be UEFI only so I'm not able to start UBCD from a connected USB pen drive.

When looking at the partitions in Windows I get this:

Using GParted Live two additional partitions are shown:

I also tried running hdparm with -N and --dco-identify but only got a HDIO_DRIVE_CMD(identify) failed: Invalid argument

My question (before I spend time investigating how to delete HPA and DCO on an UEFI only device): Is the possible presence of HPA and DCO limited to ATA devices like HDD and SSD? Or rather: Is an eMMC an ATA device?

Answer 1

EMMCs aren't ATA, they are a different interface , and detected differently by linux. In fact these are essentially SD cards connected directly to the system, to the point where you can bodge one into a sd card.

While I'm not sure what driver they use in linux, they clearly don't use the universal ata drivers, and I don't think hdparm will work.

PATA and SATA devices are /dev/sdX, while emmcs are /dev/mmcblk0

the 128mb partition looks like an MSR and is essential for windows. The one mb partition may be a backup GPT table.

Considering that DCO is there for legacy compatibility, and EMMCs have no 'legacy' version, its doubtful. Not sure about HBA, but I doubt it.

Interestingly a quick look through NIST's guidelines for media sanitation treats hard drives and embedded memory differently and simply recommends factory resetting such devices to clear it.

So, no, they're unlikely to have either of them.