В PCI Local Bus Specification пишут:
One major difference in the usage model between PCI expansion ROMs and standart ISA, EISA, and MC ROMs is that the ROM code is never executed in place. It is always copied from the ROM device to RAM and executed from RAM.
Вроде только в этом и Expansion ROM Base Address Register отличие.
В PCI Local Bus Specification пишут:
One major difference in the usage model between PCI expansion ROMs and standart ISA, EISA, and MC ROMs is that the ROM code is never executed in place. It is always copied from the ROM device to RAM and executed from RAM.
Вроде только в этом и Expansion ROM Base Address Register отличие.