I own a CM3588 NAS board from FriendlyElec. The eMMC drive was factory-installed with the FriendlyElec version of OpenMediaVault, and any other FriendlyElec or Armbian image could be booted from an SD card. After installing the current version of Armbian OpenMediaVault (Debian 12 Bookworm - Armbian Linux v6.1 Build Date: Mar 6, 2025) on eMMC and updating bootloader via armbian-config (option Boot from eMMC + system on eMMC), nothing else can be booted from the SD card except Armbian images.
Please, is there a simple way to fix bootloader back to original option of booting FriendlyElec images from SD card without having to erase entire eMMC drive? Boot from SD card does not work even for FriendlyElec automatic eflasher (SD to eMMC) images.
I have Windows 11 and RKDevTool 3.30 is quite confusing and too complex software for me.
PS. Does the CM3588 NAS board have SPI NOR flash? And how can I upload UEFI 1.1 boot (https://github.com/edk2-porting/edk2-rk3588) to eMMC or to SPI NOR?