Browse Prior Art Database

Method for supporting legacy and EFI 1.1 option ROMs

IP.com Disclosure Number: IPCOM000010049D
Publication Date: 2002-Oct-16
Document File: 2 page(s) / 87K

Publishing Venue

The IP.com Prior Art Database

Abstract

Method for supporting legacy and the extensible firmware interface (EFI 1.1) option read-only memory (ROM) devices. Benefits include improved functionality and improved support for future products.

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Method for supporting legacy and EFI 1.1 option ROMs

Method for supporting legacy and the extensible firmware interface (EFI 1.1) option read-only memory (ROM) devices. Benefits include improved functionality and improved support for future products.

Background

      Conventionally, 64-bit architecture based systems support only 32-bit (legacy) or 64-bit native mode (EFI 1.1) option ROMs but not both. As a result, each platform looses a substantial number of supported add-in cards, resulting in a loss of sales into the particular market associated with those cards.

Description

              The disclosed method supports both legacy 32-bit and EFI 64-bit native-mode option ROMs in a 64-bit architecture-based system (see Figure 1). While in 32-bit emulation mode, all option ROM contents are copied into a hand-off area visible to both 32-bit emulation and 64-bit native mode code. In addition, an option ROM descriptor is created. ROMs that contain legacy 32-bit images and no EFI images are copied into shadow RAM, and the initialization code is executed.

              A flag in the descriptor is set to indicate that the legacy image has been run. Before leaving 32-bit emulation, the address and number descriptors is passed back to the 64-bit processor, which then loads EFI. It examines the option ROM descriptors for EFI 1.1 images. They are started as EFI initializes. It has services available from both the EFI and legacy option cards. In addition , the execution of both 32-bit legacy and 64-bit native mode option ROMs are controlled with system BIOS set-up options.

      The disclosed method provides improved support for future products. They will not be restricted by the set of supported add-in cards. This is particularly important in the area of high performance RAID controllers, which require that the number of excluded cards be minimized.

Advantages

      Some implementations of the disclosed structure and method provide one or more of the follo...