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Multiboot and Multiconfig

Starting with v6.0.0, compatible editions can keep several F4HWN firmware images in the radio’s external Flash and restore one from a selector at startup. Each firmware slot has its own configuration bank by default, so trying another edition does not overwrite the channels and settings used by the other slots.

Multiboot is included in the four official v6.0.0 editions: Fusion, FieldOps, Transfer, and Labs. Firmware slots are managed with UV Studio while the radio is running normally.

[!IMPORTANT] Only put a v6.0.0 or newer F4HWN image with Multiboot support in a firmware slot. A v5.x, stock, or other non-Multiboot firmware may run after being restored, but it cannot open the startup selector to return to another slot.

Firmware slots

The radio keeps five Multiboot entries:

Radio label Purpose Managed by
M Main, an automatic backup of the firmware installed through the normal flashing procedure firmware
1 to 4 additional F4HWN firmware images UV Studio

Main is protected from host writes. On the first boot of a Multiboot-capable firmware installed through the normal Flash Firmware procedure, the radio displays Init Main and copies the running firmware into M. Do not switch the radio off during this initialization.

The four user slots live only in external Flash until selected. Installing or erasing one in UV Studio does not immediately replace the firmware currently running from internal Flash.

Installing a firmware in a slot

  1. Start the radio normally with a Multiboot-enabled firmware.
  2. Connect it to a desktop browser with a supported USB data connection.
  3. Open UV Studio and select Firmware Slots.
  4. Select a compatible stable v6.x F4HWN build from the catalog, or choose a compatible local .bin file.
  5. Choose slot 1, 2, 3, or 4 and optionally edit its display name.
  6. Select Write to slot, confirm, and wait for the erase, write, and verification steps to finish.

Each slot accepts an application image up to 118 KiB. UV Studio writes the image to external Flash, stores its size and CRC, then asks the radio to verify the complete image.

Erase FW removes the external firmware image from that user slot. It does not erase the slot’s configuration bank and does not affect a copy of that firmware already running in internal Flash.

Selecting a firmware at startup

  1. Switch the radio off.
  2. Hold M (MENU) by itself while switching the radio on. Do not hold PTT.
  3. Release the key when the F4HWN MULTIBOOT screen appears.
  4. Wait while the radio scans and validates the slots.
  5. Use UP / DOWN on UV-K5, or LEFT / RIGHT on UV-K1, to select M or slot 1 to 4. The active layout follows SetNav.
  6. Press M to select it, then press M again on Restore ...? to confirm.
  7. Do not switch the radio off during Writing / Verify. The radio restarts automatically with the selected firmware.

Press EXIT from the slot list to cancel and continue starting the firmware already installed. Invalid, incomplete, oversized, or CRC-failing slots are displayed but cannot be restored.

The selector initially highlights the slot from which the running firmware came. It is also mirrored in UV Studio when that support is available.

Multiconfig: one configuration bank per slot

By default, selecting firmware slot N also selects configuration bank N:

Firmware Default configuration Contents kept in that bank
Main (M) CFG M memory channels, names, VFOs, scan lists, and radio settings
slot 1 CFG 1 its own copy of the same configuration areas
slot 2 CFG 2 its own copy of the same configuration areas
slot 3 CFG 3 its own copy of the same configuration areas
slot 4 CFG 4 its own copy of the same configuration areas

Calibration data, the boot logo, Multiboot metadata, firmware/app slots, and the RF log are shared rather than duplicated in each bank.

An unused configuration bank starts with factory defaults the first time it is used. This separation is useful when editions have different settings or when you want to test a firmware without modifying the normal Main configuration.

Using SetCfg

The SetCfg menu lets the running firmware use a different configuration bank without changing firmware. For example, SLOT 2 / CFG 4 means that the firmware restored from slot 2 is currently using the channels and settings stored in bank 4.

  1. Open the normal menu and select SetCfg.
  2. Choose CFG M, CFG 1, CFG 2, CFG 3, or CFG 4.
  3. Press M, then press M again at SURE?.
  4. The radio restarts and maps the selected bank.

Confirming the bank already in use is a no-op and does not restart the radio. The SysInf identity page shows separate SLOT and CFG badges so you can always check the current combination.

[!CAUTION] SetCfg deliberately allows configurations to be shared across firmware editions and versions. Compatibility is your responsibility. Back up important channel/settings data before opening a bank with firmware that may use a different data layout.

In UV Studio, Reset config erases the configuration bank associated with user slot 1 to 4 without erasing its firmware. The next boot using that bank recreates default settings. CFG M is protected from this command; use the firmware’s normal factory-reset procedure for the Main configuration.

Recovery and safety notes