Apply latest firmware to a Dell/Brocade M8428-k converged Ethernet/FC switch via TFTPBOOT

there is a M8428-k ethernet switch with old firmware. Somehow firmware upgrade did work for a while but after powercycling the system hangs at boot. We can still get into the rom monitor and network boot via tftp. However we do not have a matching tftp boot image for that hardware. The upgrade file was basically a patch to a linux os with install files and RPMs. However netbooting would require a kernel and initrd for this platform. Your job is to a) find the absoute latest firmware for this hardware. b) find a proper way to tftpboot and install this firmware on to the dead switch. c) document the procedure (theres a second one we have to do). Alternatively, a 1:1 disk image which can be flashed on to the flash (if its somehow removable) or a boot from USB stick could also be a solution.