Intel Extensible Firmware Interface - Manual (Page 721)

Protocols — Debugger Support
Version 1.10 12/01/02 16-7
NOTE
When the context record field is larger than the register being stored in it, the upper bits of the
context record field are unused and ignored.
// System context for IA-32 processors
typedef struct {
UINT32
ExceptionData; // ExceptionData is
// additional data pushed
// on the stack by some
// types of IA-32
// exceptions
EFI_FXSAVE_STATE FxSaveState;
UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
UINT32 Cr0, Cr1 /* Reserved */, Cr2, Cr3, Cr4;
UINT32 Eflags;
UINT32 Ldtr, Tr;
UINT32 Gdtr[2], Idtr[2];
UINT32 Eip;
UINT32 Gs, Fs, Es, Ds, Cs, Ss;
UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
} EFI_SYSTEM_CONTEXT_IA32;
// FXSAVE_STATE - FP / MMX / XMM registers
typedef struct {
UINT16
Fcw;
UINT16 Fsw;
UINT16 Ftw;
UINT16 Opcode;
UINT32 Eip;
UINT16 Cs;
UINT16 Reserved1;
UINT32 DataOffset;
UINT16 Ds;
UINT8 Reserved2[10];
UINT8 St0Mm0[10], Reserved3[6];
UINT8 St0Mm1[10], Reserved4[6];
UINT8 St0Mm2[10], Reserved5[6];
UINT8 St0Mm3[10], Reserved6[6];
UINT8 St0Mm4[10], Reserved7[6];
UINT8 St0Mm5[10], Reserved8[6];
UINT8 St0Mm6[10], Reserved9[6];
UINT8 St0Mm7[10], Reserved10[6];
UINT8 Reserved11[22 * 16];
} EFI_FXSAVE_STATE;