Specifications

46
EFI_LEGACY_BIOS_PROTOCOL.PrepareToBootEfi()
Summary
This function is called when booting an EFI-aware OS with legacy hard disks. The legacy
hard disks may or may not be the boot device but will be accessed by the EFI-aware OS.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_LEGACY_BIOS_PREPARE_TO_BOOT) (
IN EFI_LEGACY_BIOS_PROTOCOL *This
OUT UINT16 *BbsCount,
OUT BBS_TABLE **BbsTable
)
Parameters
This
Indicates the EFI_LEGACY_BIOS_PROTOCOL instance.
BbsCount
Number of BBS_TABLE structures.
BbsTable
BBS entry. Type BBS_TABLE is defined in "Related Definitions" in
Compatibility16PrepareToBoot().
Description
This function is called when booting an EFI-aware OS with legacy hard disks. The
Compatibility16 code needs to assign drive numbers for BBS entries. The
AssignedDriveNumber field in the BBS Table reports back the drive number assigned by
the 16-bit CSM. Use
EFI_LEGACY_BIOS_PROTOCOL.LegacyBoot() for booting a
legacy OS.
Status Codes Returned
EFI_SUCCESS Tables returned successfully.