The Pointer to PCI Data Structure is supposed to be two bytes. It is described in the PCI Firmware Specification Revision 3.0, section 5.1.1. PCI Expansion ROM Header Format. The pointer is two bytes at 0x18. The pointer is supposed to be a multiple of 4 which means there's always at least two bytes of padding after the pointer. Some BIOS firmware images may use the 2 bytes following the pointer for other purposes (plus additional bytes before the PCI Data Structure) so we cannot assume the bytes will be zero. Some PCI expansion ROMs may include both BIOS and Open Firmware images.
The Pointer to PCI Data Structure is supposed to be two bytes. It is described in the PCI Firmware Specification Revision 3.0, section 5.1.1. PCI Expansion ROM Header Format. The pointer is two bytes at 0x18. The pointer is supposed to be a multiple of 4 which means there's always at least two bytes of padding after the pointer. Some BIOS firmware images may use the 2 bytes following the pointer for other purposes (plus additional bytes before the PCI Data Structure) so we cannot assume the bytes will be zero. Some PCI expansion ROMs may include both BIOS and Open Firmware images.