DS115j Debian install kit

Bring a Synology DS115j (Marvell Armada 370, 256 MiB RAM) to the same Debian 13 (trixie) armhf daily-ready state as the live box on this LAN, or reinstall this one.

This is a self-contained UART + TFTP + HDD kit. A fresh clone contains the known-good boot artifacts and the complete Debian rootfs payload.

For a complete helper-free daily-ready install or reinstall, follow only docs/install-uart.md.

Daily-ready scope (2026-09-16)

HDD boot from ide 0:2, SSH, DHCP + permanent .233, RGMII Ethernet, MCU LEDs/beep, temperature fan, SMART → bay amber only on failure, 10-minute HDD spin-down, zram, chrony, qnap_poweroff_ds115j PSU cut. Samba/backups/nftables are out of scope.

Live probe: docs/current-state.md. Cold-boot checklist: docs/cold-boot-verify.md.

Access (trusted LAN only)

Full notes: docs/access.md.

Current good boot files

Verify after copy:

cd boot && shasum -a 256 -c SHA256SUMS

Kernel / ramdisk / modules/qnap-poweroff-ds115j.ko are one set. Vermagic: 6.12.107+deb13-armmp. Do not apt upgrade the kernel as a routine update.

Board DTS (good): dts/ds115j.dts SHA 89bc51c8…. The file dts/ds115j.dts.stale-with-alarm-gpios is labelled do not build.

Layout

docs/install-uart.md   NEW DEVICE + REINSTALL (manual UART)
docs/landmines.md      never ide 0:1, never casual saveenv, …
docs/recovery.md       TFTP / sda2 rollback
docs/led-behaviour.md
docs/smart-amber-led.md
docs/disk-idle.md
docs/current-state.md
scripts/               MCU, fan, SMART amber, deploy-boot, bootstrap
dts/                   good DTS/DTB
boot/                  uImage + ramdisks
firmware/spi/          8 MiB SPI dump (unbrick reference; do not rewrite SPI)
modules/               qnap_poweroff_ds115j.ko + source
rootfs/                split Debian rootfs archive (<95 MB per Git object)
config/                interfaces, smartd, systemd examples from the live NAS
HANDOFF/               historical bring-up notes

Landmines (read before any U-Boot)

• Never ide 0:1 (hangs). Boot files live on ide 0:2 (sda2).
• Never casual saveenv / sf write / bubt / fw_setenv (env sits inside stock zImage in SPI).
• Do not run scripts/extract-hdd.sh on the live NAS — it wipes /dev/sda and is a stale single-partition recipe.
• Do not attach disk-activity to the bay amber LED.

Full list: docs/landmines.md.

Rootfs included in git

GitHub rejects individual files over 100 MB, so the 134,385,614-byte archive is committed as two ordinary Git files:

Reconstruct and verify the original archive:

scripts/reconstruct-rootfs.sh
# rootfs-trixie-armhf.tar.gz SHA-256:
# 9d869bf8f45f6f3908097aece847bb2d1bde4a6213801cb8460cdb83f9a30eb6

No Git LFS client or helper host is required. To rebuild from Debian mirrors instead, a Linux machine with mmdebstrap can run sudo scripts/bootstrap-rootfs.sh.

First-boot dpkg --configure -a and apt-get need Internet on the NAS.

Laptop serving

Give the laptop a LAN address such as 192.168.68.251/22, then run:

scripts/serve-tftp.sh

The script stages and serves the three files in boot/. The former Raspberry Pi helper is historical and optional; installation and recovery do not use it.