I took an image of the entire /dev/mmcblk0 from the "fastboot rescue mode". This way I can view the partition layout with parted or gdisk on my computer without risking any damage by accidental modifications. Not sure if there is anything useful in this, at least some of these have names that may reveal their function. I guess all those "Q*" partitions are something internal from Qualcomm and probably uninteresting. The bootloader chain would be "rpm" -> "sbl1" -> "sbl2" -> "sbl3" -> "aboot" according to some sources on other Qualcomm-based Android phones that turned up on a quick web search (sbl = secondary bootloader). "persist" is mounted on /persist and appears to contain WLAN driver configuration, including MAC addresses. "drm" is mounted on /drm and it's currently empty despite the standard lost+found directory. No idea about "security" and some of the others, though. I don't think these partitions are scary, this is just the way it is set up by Qualcomm as vendor. In defense of Jolla, what would be the purpose of documenting this publicly? I would even expect that the documentation provided by Qualcomm is under a NDA…