Combined UEFI BIOS & OS image on SD card

Is it possible to combine one of the HoneyComb UEFI BIOS images from SolidRun with an OS image that uses GPT partitions?

I use UEFI on SD to boot NetBSD on a HDD. I would like to create a combined OS + UEFI BIOS installation/recovery image on an SD card. If I shorten the GPT table slightly and reserve some space between the end of the GPT table and the first OS partition, then I think I can overlay the UEFI BIOS image with the OS image.

I am assuming that the large, contiguous all-0 regions in the UEFI BIOS are disused. Not so?

Will the UEFI BIOS write back to the SD card—for example, to start BIOS boot parameters? Are there any particular regions that I need to reserve for writeback?

If anyone has experience producing combined UEFI BIOS + OS images for the HoneyComb board, I’d love to hear about it.

David

In theory this is possible, but not something we support. The design of the edk2 reference is to be tested on uSDHC by itself, or be run from SPI-NOR flash.