Intel Extensible Firmware Interface - Manual (Page 718)

Extensible Firmware Interface Specification
16-4 12/01/02 Version 1.10
InvalidateInstructionCache
Invalidate the instruction cache of the processor. This is required by
processor architectures where instruction and data caches are not
coherent when instructions in the code under debug has been modified
by the debug agent. See the
InvalidateInstructionCache() function description.
Related Definitions
Refer to the Microsoft PE/COFF Specification revision 6.2 or later for IMAGE_FILE_MACHINE
definitions.
NOTE
At the time of publication of this specification, the latest revision of the PE/COFF specification
was 6.2. The definition of IMAGE_FILE_MACHINE_EBC is not included in revision 6.2 of the
PE/COFF specification. It will be added in a future revision of the PE/COFF specification.
typedef enum {
IsaIa32 = IMAGE_FILE_MACHINE_I386, // 0x014C
IsaIpf = IMAGE_FILE_MACHINE_IA64, // 0x0200
IsaEbc = IMAGE_FILE_MACHINE_EBC // 0x0EBC
} EFI_INSTRUCTION_SET_ARCHITECTURE
Description
The EFI Debug Support protocol provides the interfaces required to register debug agent callback
functions and to manage the processor’s instruction stream as required. Registered callback
functions are invoked in interrupt context when the specified event occurs.
The driver that produces the EFI Debug Support protocol is also responsible for saving the
machine context prior to invoking a registered callback function and restoring it after the callback
function returns prior to returning to the code under debug. If the debug agent has modified the
context record, the modified context must be used in the restore operation.
Furthermore, if the debug agent modifies any of the code under debug (to set a software
breakpoint for example), it must call the
InvalidateInstructionCache() function for
the region of memory that has been modified.