User`s guide

ROM Partitioning

B.1 Firmware EPROM Layout

Figure B–4 Boot Information Pointers

Def Boot Dev Dscr Ptr

Def Boot Flags Ptr

ASCIZ Dev Name String

Boot Flags (Longword)

Boot Device String Ptr

Class

Type

Desc Length

20040018

2004001c

MLO-007701

The following macro deﬁnes the boot device descriptor format.

;-------------------------------------------------------------

; Default Boot Device Descriptor

;

boot_device_descriptor::

base = .

. = base + dsc$w_length

.word nvr$s_boot_device

. = base + dsc$b_dtype

.byte dsc$k_dtype_z

. = base + dsc$b_class

.byte dsc$k_class_z

. = base + dsc$a_pointer

.long nvr_base + nvr$b_boot_device

. = base + dsc$s_dscdef1

;-------------------------------------------------------------

B–8 ROM Partitioning