JumpDrive isn't working

[phytocube]

I have a Beta edition PinePhone which had the default Manjaro OS installed, but things started breaking after I pacman -Sy && pacman -Su-ed it. The first warning sign was the on-screen keyboard not showing up on the SDDM lock screen, and after a reboot, SDDM outright failed to start. sshd was still working, so I installed and started LXDM (after stopping and disabling SDDM), and although it started succesfully, the on-screen keyboard still failed to show up. 

Next, I tried replacing the contents of /etc, /usr, /var, and /opt on the eMMC with a fresh copy from Manjaro's PinePhone image by copying them over without flashing the entire drive (which was a horrible idea in retrospect and wouldn't have saved any time vs. reflashing from microSD), but something went horribly wrong because sshd went down almost immediately, and I can't tell if the phone is on any more.

Just now, I dd-ed JumpDrive onto a microSD card and booted my phone, but the only difference seems to be that a green LED in the upper left corner of the front of the phone turns on; the screen itself is off, and I don't see any new block devices from my PC. I think my immediate questions boil down to these:

1. Is my host PC missing a driver? dmesg doesn't seem to have picked up any plugging/unplugging events while the phone is on and ostensibly booted into JumpDrive. lsusb likewise doesn't change with the phone connected or disconnected. If the kernel driver needed to detect a PinePhone running JumpDrive isn't installed/loaded by default on a typical Arch system, this could be a quick and easy fix.
   
2. Is it normal for JumpDrive to start with a blank screen? If not, how should I troubleshoot it? I've already downloaded the image twice with cache cleared, and the checksums match.
   
3. If all else fails, is there a way to have the eMMC reflashed more "manually?" I don't have much in the way of appropriate tools/equipment, though...
   

Thanks!

[zetabeta]

1. Is my host PC missing a driver? dmesg doesn't seem to have picked up any plugging/unplugging events while the phone is on and ostensibly booted into JumpDrive. lsusb likewise doesn't change with the phone connected or disconnected. If the kernel driver needed to detect a PinePhone running JumpDrive isn't installed/loaded by default on a typical Arch system, this could be a quick and easy fix.
   
2. Is it normal for JumpDrive to start with a blank screen? If not, how should I troubleshoot it? I've already downloaded the image twice with cache cleared, and the checksums match.
   
3. If all else fails, is there a way to have the eMMC reflashed more "manually?" I don't have much in the way of appropriate tools/equipment, though...
   

Thanks!

1:
no, jumpdrive should work by default drivers in both linux pc and windows pc. and lsusb should show something. although i found some kind of bug in linux pc, that shows sizes wrong, probably related to eject command, reboot fixes it.
2:
no. screen should display something. basically jumpdrive logo/picture.
3:
you could install o.s. into sdcard and maybe after that using this installed o.s. yet again install into emmc. if the images are same, uuid's might bring some confusion, be careful (hint blkid).

one serious hint though, use "sync" command after dd command, because linux system usually do not write data immediately to the mass media.

[phytocube]

1. Is my host PC missing a driver? dmesg doesn't seem to have picked up any plugging/unplugging events while the phone is on and ostensibly booted into JumpDrive. lsusb likewise doesn't change with the phone connected or disconnected. If the kernel driver needed to detect a PinePhone running JumpDrive isn't installed/loaded by default on a typical Arch system, this could be a quick and easy fix.
   
2. Is it normal for JumpDrive to start with a blank screen? If not, how should I troubleshoot it? I've already downloaded the image twice with cache cleared, and the checksums match.
   
3. If all else fails, is there a way to have the eMMC reflashed more "manually?" I don't have much in the way of appropriate tools/equipment, though...
   

Thanks!

1:
no, jumpdrive should work by default drivers in both linux pc and windows pc. and lsusb should show something. although i found some kind of bug in linux pc, that shows sizes wrong, probably related to eject command, reboot fixes it.
2:
no. screen should display something. basically jumpdrive logo/picture.
3:
you could install o.s. into sdcard and maybe after that using this installed o.s. yet again install into emmc. if the images are same, uuid's might bring some confusion, be careful (hint blkid).

one serious hint though, use "sync" command after dd command, because linux system usually do not write data immediately to the mass media.

1, 2: I got JumpDrive to work after playing around with the block size on a lark. 64K worked, but I'm not sure if that was before or after I brought /proc/sys/vm/dirty_*_ratio down to 1% from 10% and 20%. Looking back, since it was probably a buffering issue, sync would indeed have worked just as well without possibly introducing host system-wide side-effects, although I watched the progress with atop and only ever ejected the SD card after write activity to /dev/sda dropped off the monitor.
3: Luckily, flashing the eMMC with JumpDrive finally worked, and the phone is now back to normal! Thanks for looking into this.

Addendum: I'll add that I somehow downloaded and flashed the PinePhonePro Manjaro image instead of the PinePhone one at some point, and the former doesn't seem to be bootable on a PinePhone in case this helps someone in the future.