pmb: allow embedding multiple firmware binaries into SD images
@ollieparanoid @MartijnBraam (and others?): I would like a review of the contents of this MR before I convert exiting devices that use u-boot (mainly, the binary/firmware path used and deviceinfo parameter names). Once those are settled, I'll submit another commit to include those changes (if any)
This has been tested on the librem5 devkit.
This allows embedding multiple firmware binaries into SD images. Firmware images for most devices that require this functionality consist mainly of u-boot, but some devices (e.g. librem5) have multiple firmware images that need to be embedded in the SD image created by pmbootstrap.
This functionality uses two new deviceinfo parameters:
deviceinfo_sd_embed_firmware: a comma-separated list of binary:offset (where binary is under /usr/share/firmware)
deviceinfo_sd_embed_firmware_step_size: The number of bytes for each increment of the offset specified in the deviceinfo_sd_embed_firmware (typically 1024 or 2048)