I just had a look at the HFI paper, and I want to say that I have been waiting for this for a long time (both for ARM and RISCV), so I hope this becomes successful !
One question : in your mind, the device tree blob could/would be embedded in the same package as this HFI firmware (so that there is no longer a need to install the DTB separately on the emmc, and even a 10-year old board with a fresh SSD/flash could boot with a generic Linux kernel) ? Will you also consider to have an UI for the user to manage secure boot keys (similar to mokutil) in this firmware ?
Another question for silicon experts : on PCs, there is usually a NOR flash that hosts the BIOS/UEFI. On ARM/RISCV boards, u-boot and DTB are often stored on the same media as the OS, which means that a fresh install requires to have access to the proper board-specific u-boot and DTB (which may be difficult when reviving an old board) => is there technically a way to colocate some kind of flash memory on the same die as the CPU to store this HFI+DTB rom, that would persist even if the main NAND/emmc/SSD hosting the OS is wiped out, and would also avoid the cost of an external NOR flash ?
Another question for silicon experts : on PCs, there is usually a NOR flash that hosts the BIOS/UEFI. On ARM/RISCV boards, u-boot and DTB are often stored on the same media as the OS, which means that a fresh install requires to have access to the proper board-specific u-boot and DTB (which may be difficult when reviving an old board) => is there technically a way to colocate some kind of flash memory on the same die as the CPU to store this HFI+DTB rom, that would persist even if the main NAND/emmc/SSD hosting the OS is wiped out, and would also avoid the cost of an external NOR flash ?