written firmware successful to boot1…also found a nice guide from daniel here just used usb to transfer the files and used original files without concatenating before
usb start
mmc partconf 0 1 2 2
mmc erase 0x0 0x120
load usb 0:1 $loadaddr EthMD32.dm.bin
mmc write $loadaddr 0x0 0x20
load usb 0:1 $loadaddr EthMD32.DSP.bin
mmc write $loadaddr 0x20 0x100
mmc partconf 0 1 1 0
but have not tested it as i need to patch out my builtin-firmware before