Intel Extensible Firmware Interface - Manual (Page 792)

Extensible Firmware Interface Specification
19-18 12/01/02 Version 1.10
OPERATION:
R0 <= R0 – 16
[R0] <= IP + SizeOfThisInstruction
IP <= IP + SizeOfThisInstruction + Operand 1 (relative CALL)
IP <= Operand 1 (absolute CALL)
Table 19-13 CALL Instruction Encoding
BYTE DESCRIPTION
Bit Description
7 0 = Immediate/index data absent
1 = Immediate/index data present
6 0 = CALL32 with 32-bit immediate data/index if present
1 = CALL64 with 64-bit immediate data
0
0..5 Opcode = 0x03
Bit Description
6..7 Reserved = 0
5 0 = Call to EBC
1 = Call to native code
4 0 = Absolute address
1 = Relative address
3 0 = Operand 1 direct
1 = Operand 1 indirect
1
0..2 Operand 1
2..5 Optional 32-bit index/immediate for CALL32
2..9 Required 64-bit immediate data for CALL64