README: the modemst wipe is 'fastboot flash boot', precisely

Isolated by experiment (2026-08-09, journal/modem): flash boot alone
zeroes modem NV; erase dtbo and idle fastboot visits are safe; on-device
boot-deploy (incl. apk kernel upgrades) never trips it. Likely ABL
anti-tamper on boot-image overwrite under an unlocked bootloader.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
Jorijn van der Graaf 2026-08-09 01:10:16 +02:00
commit 42d28305ca

View file

@ -41,15 +41,20 @@ Default login: `user` / `147147` (same as official postmarketOS images —
change it). **Never re-lock the bootloader** with a custom image installed. change it). **Never re-lock the bootloader** with a custom image installed.
> [!WARNING] > [!WARNING]
> **Back up your modem's NV partitions before flashing.** Flash sessions have > **`fastboot flash boot` zeroes the modem's NV storage on this device**
> been observed to zero `modemst1`/`modemst2` on this device, after which the > (`modemst1`/`modemst2`) — verified by isolation experiment; `fastboot erase
> modem reports no IMEI and neither SIM slot answers (`no-atr-received`) — > dtbo` and idle fastboot sessions are safe. Afterwards the modem reports no
> including the eSIM. The profiles themselves are safe in the eUICC, but only > IMEI and neither SIM slot answers (`no-atr-received`), eSIM included. The
> a restore of working `modemst` images brings access back; stock Android > eSIM profiles themselves are safe in the eUICC; stock Android silently
> re-provisions them on boot, postmarketOS cannot. Before your first flash: > re-provisions the NV from `fsg` on boot, postmarketOS cannot.
> `dd` both partitions to files from a rooted stock system (or from a running >
> pmOS: `/dev/disk/by-partlabel/modemst1` and `modemst2`) and keep them > Practical rules:
> forever. Restore with `dd` in the other direction, then reboot. > - **Back up first**: from a running postmarketOS (or rooted stock), `dd`
> `/dev/disk/by-partlabel/modemst1` and `modemst2` to files, keep forever.
> - **After install, restore them**: `dd` back and reboot — cellular returns.
> - **Never update the kernel via fastboot** — installed systems update boot
> through on-device `boot-deploy` (which apk kernel upgrades run
> automatically), never tripping the wipe.
## VoLTE configuration ## VoLTE configuration