Specifications

Code Definitions
41
• Reconfigure SIO devices from EFI mode (polled) into traditional mode
(interrupt driven).
• Shadow all PCI ROMs.
• Set up BDA and EBDA standard areas before the legacy boot.
• Construct the Compatibility16 boot memory map and pass it to the
Compatibility16 code.
• Invoke the Compatibility16 table function
Compatibility16PrepareToBoot(). This invocation causes a thunk
into the Compatibility16 code, which sets all appropriate internal data
structures. The boot device list is a parameter.
• Invoke the Compatibility16 Table function Compatibility16Boot().
This invocation causes a thunk into the Compatibility16 code, which does an
INT19.
• If the
Compatibility16Boot() function returns, then the boot failed in
a graceful manner—i.e., EFI code is still valid. An ungraceful boot failure
causes a reset because the state of EFI code is unknown.
Related Definitions
//****************************************************
// BBS_BBS_DEVICE_PATH
//****************************************************
#define BBS_DEVICE_PATH 0x05
#define BBS_BBS_DP 0x01
typedef struct _BBS_BBS_DEVICE_PATH {
EFI_DEVICE_PATH_PROTOCOL Header;
UINT16 DeviceType;
UINT16 StatusFlag;
CHAR8 String[1];
} BBS_BBS_DEVICE_PATH;
Header
The device path header. Type EFI_DEVICE_PATH is defined in
LocateDevicePath() in the EFI 1.10 Specification.
DeviceType
Device type as defined by the BBS Specification. Defined device types are listed in
"Related Definitions" in
Compatibility16PrepareToBoot().
StatusFlag