Xiaomi Redmi Note 9S → postmarketOS

Pre-built postmarketOS v25.12 + Phosh flash bundle for the Xiaomi Redmi Note 9S (pmaports codename xiaomi-miatoll, SKU curtana). Likely also works on the Redmi Note 9 Pro (joyeuse) and Note 9 Pro Max (excalibur) — same miatoll family, untested by me. ~10 minutes to lockscreen. Ships with the Plymouth workaround you'll otherwise hit at the pmOS logo + "Loading…" forever. The same hardware also runs classic GNOME on edge (see second row).

Phosh (this bundle):

Lockscreen	App drawer	Console + fastfetch

Classic GNOME on edge (pmbootstrap config ui gnome + is_default_channel True):

Activities overview	VSCode (dark)	Firefox	Files + Editor

Download

git clone https://github.com/asidko/redmi-note-9s-postmarketos
cd redmi-note-9s-postmarketos
./download.sh                  # grabs binaries from the latest release, decompresses, verifies

download.sh fetches the four files below from GitHub Releases (they don't live in git — GitHub's hard limit is 100 MB per file).

File	Size	Compressed	Goes to
xiaomi-miatoll-boot.img	256 MiB	.img.zst ~25 MB	cache (kernel partition on miatoll)
xiaomi-miatoll-root.img	2.5 GiB	.img.zst ~800 MB	userdata
u-boot-sm7125.img	1008 KiB	not compressed	boot (mainline U-Boot for SM7125)
SHA256SUMS	—	—	integrity check

⚠️ Read first

• Destructive. Wipes cache, userdata, boot. Modem, persist, keymaster, devcfg, super survive — radio works, revert to MIUI possible.
• Tested on Redmi Note 9S (curtana). The same images may work on joyeuse / excalibur (Note 9 Pro / Pro Max — miatoll family) but are untested there.
• Never flash *-boot.img to boot — on miatoll, cache = kernel, boot = U-Boot. Swap = brick.
• Battery ≥ 30 %. No power-cycle mid-flash.

Prerequisites

Laptop: Linux + fastboot (apt install android-tools-fastboot android-sdk-platform-tools-common, or your distro's equivalent) + zstd. Optional but recommended: gh (GitHub CLI) — download.sh uses it for faster, resumable transfers if present, otherwise falls back to curl. USB data cable. Run fastboot with sudo if udev rules aren't installed.

Phone — bootloader must be unlocked. Three steps, 5–7 days total:

0. Sign in to https://account.xiaomi.com/ — confirm the Mi account is active, signed in on the phone, with a verified email (Xiaomi rejects unlock requests without one).
1. Submit the unlock request (cross-platform): https://github.com/offici5l/MiUnlockTool
2. Wait 5–7 days (Xiaomi-account-age gated, no skip).
3. Do the unlock (Windows-only, official): https://en.miui.com/unlock/download_en.html

Verify: fastboot oem device-info shows Device unlocked: true.

Flash

You're already in the cloned repo folder from the Download step above — the next commands run from there. download.sh already verified checksums; re-run sha256sum -c SHA256SUMS only if you suspect corruption.

Power phone off → hold Volume DOWN + Power to fastboot → plug USB.

fastboot devices                                       # one line expected
fastboot getvar product                                # must say: product: curtana

Stop if product is anything other than curtana (joyeuse / excalibur are Note 9 Pro / Pro Max — likely OK but untested).

fastboot flash cache    xiaomi-miatoll-boot.img        # ~10 s
fastboot flash userdata xiaomi-miatoll-root.img        # ~60–120 s, 3 sparse chunks
fastboot erase dtbo                                    # mainline kernel ignores it; clearing stock dtbo avoids stale data
fastboot flash boot     u-boot-sm7125.img              # ~1 s
fastboot reboot

USB drops — that's normal. On the phone you'll see U-Boot text (~5 s) → pmOS logo → scrolling boot logs (intentional, see build notes) → Phosh lockscreen in 1–5 min on first boot.

Login

User	user
Password	1234 (also sudo)
Hostname	redmi

SSH is enabled by default. On the phone connect Wi-Fi, find the IP via Terminal: hostname -I. Then from your PC:

ssh user@<phone-ip>       # password: 1234
ssh user@redmi.local      # mDNS — macOS and most Linux work out of the box

🔒 Change the password immediately — passwd over SSH, or Settings → Users in Phosh. 1234 is unsafe.

Hardware support

xiaomi-miatoll is testing tier in pmaports. Works: Wi-Fi, cellular voice + data, audio, GPU, sensors. Broken/missing: fingerprint, NFC, HW video decode. Camera is fixable — see Camera fix below. Wiki: https://wiki.postmarketos.org/wiki/Xiaomi_Redmi_Note_9S_(xiaomi-miatoll).

Battery readings (UI-dependent)

The mainline qcom_qg fuel-gauge driver reports nonsense for the first few seconds after boot (capacity=0, status=Unknown) before it settles. The three pmOS UIs handle this differently:

• Phosh ✅ — ignores transient readings, works correctly.
• Plasma Mobile / GNOME Mobile ⚠️ — their power daemons (PowerDevil / gnome-settings-daemon) act on the first reading and trigger critical-battery-action, which by default shuts the phone off seconds after boot.

If you flash this bundle and pick anything other than Phosh, override the critical-battery action over SSH:

# GNOME Mobile
gsettings set org.gnome.settings-daemon.plugins.power critical-battery-action 'nothing'

# Plasma Mobile
kwriteconfig5 --file powerdevilrc --group BatteryManagement --key BatteryCriticalAction 0

The setting persists across reboots. The on-screen indicator may still briefly show 0% at boot, but the phone won't shut down on you.

Charging fix (mainline PM6150 SMB5)

Separate problem from the boot-transient one above: on this kernel, mainline has no charger driver bound to PM6150's SMB5 peripherals, so the bootloader-default input current limit (≈ 500 mA SDP fallback) leaves the phone losing charge while plugged in with the screen on. The fuel gauge's STATUS is also stuck on Unknown, so GNOME shows battery-missing-symbolic.

Both are fixed by a companion repo: https://github.com/asidko/pm6150-charger-mainline — two out-of-tree modules and a 4-line qcom_qg patch. Precompiled .ko files for this exact bundle's kernel are attached to the latest release. After install, charging draws ~700–750 mA at 5 V, the bolt icon shows, and termination at 100 % SoC is enforced.

Camera fix (mainline qcom-camss CSIPHY v1.2.2)

Upstream qcom-camss ships a malformed CSIPHY v1.2.2 lane register table for the Atoll family — sensors stream, but no frames reach /dev/video0. The companion repo https://github.com/asidko/qcom-camss-mainline replaces the table and adds the two missing PHY-enable writes (CTRL0 = 0x02, CTRLn(33) = 0x01) v1.2.2 silicon requires. A drop-in qcom-camss.ko for linux-postmarketos-qcom-sm7125 6.14.7-r0 is attached to the latest release.

curl -fL https://github.com/asidko/qcom-camss-mainline/releases/latest/download/install.sh | sudo bash
sudo reboot

After reboot, GNOME's Snapshot app shows live preview from the 16 MP front (OV16A1Q) and 5 MP macro (S5K5E9). Photo capture and video recording work. Verified on joyeuse; curtana and excalibur should behave identically (same SoC, same DT inheritance) but are untested.

Troubleshooting

• fastboot devices empty / "no permissions": bad/charge-only cable, missing udev, or run with sudo.
• "Volume Full" on flash: image corrupted — re-run sha256sum -c and re-download.
• Black screen > 7 min: hold Power 10 s. If dead, Vol-Down + Power → restart from the verify step. Vol-Up + Power is MIUI recovery, NOT EDL on this device.
• Stuck on pmOS logo + "Loading…": you're on a build without the Plymouth fix. This bundle has it baked in — re-flash cache from this release.
• No Wi-Fi: firmware-xiaomi-miatoll is included; reboot once. Check dmesg | grep firmware over SSH.

Build notes (for rebuilders)

pmbootstrap v3.10.1, pmaports v25.12, channel systemd-v25.12, Alpine aarch64 cross-build. Two non-default changes are required:

1. Smaller boot_size — miatoll's cache is only ~384 MiB, but pmbootstrap defaults to 512 MiB and refuses smaller. Patch sanity_check_boot_size() in pmb/install/_install.py to allow < 512 with a warning, then pmbootstrap config boot_size 256.
2. Plymouth disabled in kernel cmdline — mainline Plymouth hangs on miatoll's DRM driver (boot stalls at the pmOS logo forever). Mount the generated xiaomi-miatoll-boot.img and edit /loader/entries/pmos.conf: replace quiet loglevel=2 with plymouth.enable=0 console=tty0 systemd.show_status=true (verbose flags are optional but useful — this bundle keeps loglevel=7 and the systemd info logging so on-screen debugging is possible).