Ret syntax, Description, Operation – Intel Extensible Firmware Interface User Manual

Page 829: Behaviors and restrictions

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EFI Byte Code Virtual Machine

Version 1.10

12/01/02

19-55

RET

SYNTAX:

RET

DESCRIPTION:

This instruction fetches the return address from the stack, sets the IP to the value, adjusts the stack
pointer register R0, and continues execution at the return address. If the RET is a final return from
the EBC driver, then execution control returns to the caller, which may be EBC or native code.

OPERATION:

IP <= [R0]

R0 <= R0 + 16

Table 19-41. RET Instruction Encoding

BYTE DESCRIPTION

Bit Description

6..7

Reserved = 0

0

0..5

Opcode = 0x04

1

Reserved = 0

BEHAVIORS AND RESTRICTIONS:

• An alignment exception will be generated if the return address is not aligned on a 16-bit

boundary.

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