Firmware Updates

Firmware Updates

🐱 Custom — built for this fork (not in the original firmware).

Once you're on this firmware you never need a computer to update again — the device can pull a new build over WiFi or flash one from the SD card. Both use a dual-OTA flash layout so a failed/interrupted write rolls back to the current firmware instead of bricking.

Open the Firmware app (or Settings ▸ System ▸ Firmware ▸ Open). It offers three options:

Update over WiFi (from GitHub)

Firmware → Update over WiFi → A. It reconnects to the WiFi saved in Settings ▸ WiFi, reads this repo's latest release tag via GitHub's releases/latest redirect (no API token, no rate limit), and if it differs from the running build, downloads firmware.bin to the SD card and offers to flash it.

• The download lands in firmware.bin.part and is only promoted to firmware.bin after a complete, size-checked transfer — a dropped download never leaves a half-file for the flasher.
• TLS uses setInsecure() (no cert pinning); the OTA layer still verifies the image on flash and rolls back a bad write.
• A device must already be running a build that has this feature, so the first hop is a manual SD/USB flash; after that it self-updates.

Update from SD

Copy firmware.bin to the SD-card root, then Firmware → Update from SD → A. It streams the image into the spare OTA slot, sets it as the boot partition, and reboots. Use firmware.bin (the app image) — not the …-merged-0x0.bin.

USB Download Mode

Firmware → USB Download Mode → A reboots into the ROM serial bootloader (usb_persist_restart(RESTART_BOOTLOADER)) — no BOOT button needed — so you can flash from a computer. See Flashing and Recovery.

Flash layout (dual-OTA)

nvs       0x009000  20 KB
otadata   0x00e000   8 KB   ← records which slot to boot
app0      0x010000  7.94 MB ← runs from here
app1      0x800000  7.94 MB ← an update is written here, then booted
coredump  0xFF0000  64 KB

The two app slots are why the app has ~7.94 MB (not 16 MB) to live in — the spare copy is what makes self-update safe. A one-time USB flash of feralcat-OTA-merged-0x0.bin at 0x0 installs this layout when coming from stock.