Intel Extensible Firmware Interface - Manual (Page 839)

EFI Byte Code Virtual Machine
Version 1.10 12/01/02 19-65
EFI_EBC_PROTOCOL.CreateThunk()
Summary
Creates a thunk for an EBC entry point, returning the address of the thunk.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_EBC_CREATE_THUNK) (
IN EFI_EBC_PROTOCOL
*This,
IN EFI_HANDLE ImageHandle,
IN VOID *EbcEntryPoint,
OUT VOID **Thunk
);
Parameters
This A pointer to the EFI_EBC_PROTOCOL instance. This protocol is
defined in Section 19.11.
ImageHandle Handle of image for which the thunk is being created.
EbcEntryPoint Address of the actual EBC entry point or protocol service the
thunk should call.
Thunk Returned pointer to a thunk created.
Description
A PE32+ EBC image, like any other PE32+ image, contains an optional header that specifies the
entry point for image execution. However for EBC images this is the entry point of EBC
instructions, so is not directly executable by the native processor. Therefore when an EBC image is
loaded, the loader must call this service to get a pointer to native code (thunk) that can be executed
which will invoke the interpreter to begin execution at the original EBC entry point.
Status Codes Returned
EFI_SUCCESS The function completed successfully.
EFI_INVALID_PARAMETER Image entry point is not 2-byte aligned.
EFI_OUT_OF_RESOURCES Memory could not be allocated for the thunk.