Operating System on NVMe (without SD Card)

lykso · October 9, 2022, 2:37pm

For what it’s worth, the battery boards with under and over voltage protection are on sale in the store now, though they won’t ship for three months.

gavron · October 14, 2022, 2:28pm

Thank you both for very useful comments that will probably save me that stomach sinking feeling of “oh no I fried something.” I’m also on the waitlist for the new bat holders.

So my question is still twofold:

The schematic shows one common (-/gnd) and 8 cells (+) except that one is duplicated on both harnesses and I don’t physically see EITHER that cable OR a -/gnd crossing left-right. Do I need to DMM this, or given this is “open source HW” is there a current schematic that ACTUALLY DOES DOCUMENT how they are hooked up?
I’m not going to put in a MOSFET for a bat disco switch. I’m also not going to wire 2x 4PST switches. This isn’t rocket science. There is a solution and if I have to DMM it to find it… sigh… well whatever documentation I come up with can only help. I just wish it was in with the schematics (which see above #1) that make no sense.

On the good side, the software build stuff is nearly done, so one script to go from SD to USB/fde … next step is to add NVMe to that mix (NVMe/fde as well) and test all combinations of back and forth SD, USB, USB/fde, NVMe, NVMe/enc.

Ehud
Tucson, Arizona, US

hardcoreufo · October 14, 2022, 7:10pm

There are full schematics and KiCAD files here.

https://mntre.com/reform2/handbook/schematics.html

J2 pin 1 and J13 pin 5 are connected by a trace on the mother board. I blew this up and had to jumper them together. They are the two center pins of the battery connectors.

Hope that helps some!

lykso · October 14, 2022, 7:16pm

Looking at the PCB layouts for the battery board and the motherboard in KiCad, it seems like your “common ground” is the leftmost pin of the left battery connector. However, each negative pole of each battery also forks off through the other pins, probably to battery monitoring circuitry. To cut off the flow of power completely, you’ll probably need to install your switch between J13 and F2. (F2 is a fuse, according to the BOM, so that makes sense to me.)

So, going by the cables, that looks like the rightmost pin on the right battery connector. That seems to me to be “choke point” for the whole battery assembly.

Please verify for yourself, if you can. I’ve done this while also tending to my fussy 6-month-old son, so it’s possible I’ve missed something. I’d hate to be the cause of someone destroying their machine! I checked this by looking at the KiCad projects in this Git repository: Reform / reform · GitLab

gavron · October 14, 2022, 8:26pm

Thank you! Now that I have my new multimeter I can’t wait to get back on this. Of course there’s always the tried and true method of “cut the wire and see who screams…”

Will get on it once I finish the software project. Pics will follow. Hopefully it is that pin and now I can test it because.

E

tomicdesu · April 11, 2024, 9:38pm

This worked for me except for reform-boot-migrate nvme which complains

lsblk: /dev/nvme0n1p1: not a block device reform-boot-config FAILED to run

I made only one partition, so nvme0n1p1 does of course not exist. So what is a/the recommended partitioning? swap, /boot, …?

minute · April 11, 2024, 9:53pm

Yep, the setup needs at least two partitions, the first one usually being /boot and the second one root (/).

josch · April 11, 2024, 10:18pm

There are two main reasons why the Reform setup requires /boot to be on its own partition:

To boot encrypted NVMe
If we boot a system that is not on the SD-Card (even unencrypted) then we need to mount the partition containing kernel, initrd and dtb. If /boot is not in its own partition, then mounting that partition to /boot will result in the files being in /boot/boot. So we need to create a partition where kernel, initrd and dtb are at the root of the partition. Otherwise we cannot upgrade the kernel from the booted system.

tomicdesu · April 12, 2024, 12:51am

Ahh. OK I repartitioned/formatted, reform-migrate to the nvme worked except reform-boot-config, which complained about /boot still mounted from the SD card. So I manually unmounted it, reform-boot-config completed. And I can boot the machine and pop out the SD card so it’s working correctly…ish.

Now, /boot is on the SD card, / is on nvme0n1p1. This is acceptable to me for now until I migrate to the internal memory; will it cause me future trouble?

Any idea where SD card images are to be found? Tried the manual, which refers to https://mnt.re/system-image which 404’s. No other refernce to boot media image found in Documentation.

johkra · April 12, 2024, 4:24am

You should be able to find images at Artifacts · build (#3903) · Jobs · Reform / reform-system-image · GitLab

(linked from Documentation: MNT Reform—MNT Research GmbH; I had the same issue with the https://mnt.re/system-image link and lykso pointed me at this link)