With the recent support for uefi I’ve been testing on more hardware (small sbc w/ emmc storage) I can install to a flash drive easily enough, but it looks like a required kernel module isn’t available to list emmc module devices:
# modprobe mmc_block
modprobe: FATAL: Module mmc_block not found.
Should I open a feature request?
edit: looks like it would also need sdhci and sdhci_acpi