Jmp8, Jmp8 syntax, Description – Intel Extensible Firmware Interface User Manual

Page 805: Operation, Behaviors and restrictions

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EFI Byte Code Virtual Machine

Version 1.10

12/01/02

19-31

JMP8

SYNTAX:

JMP8{cs|cc} Immed8

DESCRIPTION:

Conditionally or unconditionally jump to a relative offset and continue execution. The offset is a
signed one-byte offset specified in the number of words. The offset is relative to the start of the
following instruction.

OPERATION:

IP = IP + SizeOfThisInstruction + (Immed8 * 2)

Table 19-22 JMP8 Instruction Encoding

BYTE DESCRIPTION

Bit Description

0 = Unconditional jump

1 = Conditional jump

0 = Jump if

Flags.C

is clear (cc)

1 = Jump if

Flags.C

is set (cs)

0..5

Opcode = 0x02

Immediate data (signed word offset)

BEHAVIORS AND RESTRICTIONS:

• If the jump is unconditional, then Byte0:Bit6 (condition) is ignored