DFU is implemented in the ROM; it is morally if not technically a subset of the open standard by the same name. Recovery mode is implemented in iBoot; it provi

DFU is implemented in the ROM; it is morally if not technically a subset of the open standard by the same name. Recovery mode is implemented in iBoot; it provides mediated access to the command interpreter and some file-ish transfer capabilities. Both are still in use; whilst the implementations have obviously evolved the fundamental interactions have not changed since the original Apple (not Samsung) ROMs.