@reostat @daveshah1 multiboot on ECP5 is possible, my "tinyfpgasp" fork uses it, makefile script generates such image using ddtcmd.exe As far as I only this lattice diamond ddt tool can generate multiboot image and prjtrellis has not reverse engineered multiboot format to have ecppack support it. Lattice datasheet about multiboot is missing. There is something on golden image boot but completely wrong (doc full of typos at important HEX numbers and basically same wrong shit copy pasted from ECP3)