How to Write an Image to the eMMC Module Tutorial

[z4v4l]

BUT since then I do have a message

blk_update_request: I/O error, dev mmcblk0rpmb, sector 0

in syslog which I'm a little bit scared of.

mmcblk0rpmb is a linux designation for "Replay Protected Memory Block", a special eMMC  partition (4MB here) for "dat security". Writes and reads there are signed, encrypted, all that thing. I think linux should not touch it without the specific reason. And I am not sure the support for this works (and works as needed) in the current linux build. It's a pretty capricious feature. I guess everything OK with it. linux just touches what it shouldn't. and gets rejected.

PS. Btw, see, the eMMC module has two boot areas, 4MB each

mmcblk0boot0 179:32 0 4M 1 disk
mmcblk0boot1 179:64 0 4M 1 disk

for firmware storage and booting. this is exactly what i was talking about when said about two SPI NOR chips for redundancy and robustness. It's safer. eMMC standard incorporates this and we have a duplicated (backed up) special firmware booting device inside an eMMC card. without touching a User Area, so that the user could use all of the bytes there for their needs. But vendors aren't bothered with such things like efficient and proper technology application. Instead they have produced 7 (!) partitions in the user area! For nothing. well.