Option Rom Allocation; Enable Or Disable Option Rom Settings - Oracle Sun Netra X4270 Service Manual

Option ROM Allocation

Option ROM Allocation
The system BIOS allocates 128 Kbytes of address space for Option ROMs. This address
space is shared between on-board devices and PCIe2 plug-in cards. This fixed address space
limitation is imposed by the PC architecture and not by the BIOS itself. It is possible to exhaust
the available address space when installing PCIe2 plug-in cards. When the address space is
exhausted, the BIOS displays an Option ROM Space Exhausted message, which means that
one or more devices cannot load Option ROMs.
By default, all on-board Options ROMs are enabled in the BIOS. However, you can disable
most of these Option ROMs, unless they are required to support booting from the associated
device or to provide some other boot time function (such as a video controller or the hardware
RAID supported through the SAS controller HBA installed in PCIe2 slot 3). For example, it
is not necessary to load the Option ROM for the on-board network ports unless you mean to
boot from one or more network ports (even then, you can disable the Options ROMs for the
remaining ports).
To enable or disable Option ROMs, see
Settings" on page
For example, if you install a SCSI PCIe2 card and you encounter the Option ROM Space
Exhausted message, you can either:
Disable the Option ROM for the PCIe2 slot you installed the SCSI card in if you will not be
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booting from that device.
Disable one or more Option ROMs for on-board devices (or slots populated with other plug-
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in cards) to ensure there is room to boot from the desired device.
Related Information
"Access the BIOS Setup Utility Menus" on page 46
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"Enable or Disable Option ROM Settings" on page 60
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"Install PCIe2 Cards Into Slots 4 and 5" on page 117
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"Install the SAS Controller HBA" on page 120
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"Install the Lower PCIe2 Cards" on page 125
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Enable or Disable Option ROM Settings

The BIOS Option ROM is 128 Kbytes. Of these 128 Kbytes, approximately 80 Kbytes are used
by the VGA controller, the disk controller, and the network interface card. Approximately 48
Kbytes remain to be shared by the Option ROMs on all bootable PCIe2 plug-in cards.
60 Sun Netra X4270 Server • September 2015
"Enable or Disable Option ROM
60.