Intel 253666-024US User Manual

Page 141

Vol. 2A 3-95

INSTRUCTION SET REFERENCE, A-M

CALL—Call Procedure

Push(IP);
CS ← DEST[31:16]; (* DEST is ptr16:16 or [m16:16] *)

EIP ← DEST[15:0]; (* DEST is ptr16:16 or [m16:16]; clear upper 16 bits *)

FI;

IF far call and (PE

1 and VM

0) (* Protected mode or IA-32e Mode, not virtual-8086 mode*)

THEN

IF segment selector in target operand NULL

THEN #GP(0); FI;

IF segment selector index not within descriptor table limits

THEN #GP(new code segment selector); FI;

Read type and access rights of selected segment descriptor;
IF IA32_EFER.LMA = 0

THEN

IF segment type is not a conforming or nonconforming code segment, call
gate, task gate, or TSS

THEN #GP(segment selector); FI;

ELSE

IF segment type is not a conforming or nonconforming code segment or
64-bit call gate,

THEN #GP(segment selector); FI;

FI;
Depending on type and access rights:

GO TO CONFORMING-CODE-SEGMENT;
GO TO NONCONFORMING-CODE-SEGMENT;
GO TO CALL-GATE;
GO TO TASK-GATE;
GO TO TASK-STATE-SEGMENT;

FI;

CONFORMING-CODE-SEGMENT:

IF L-Bit

1 and D-BIT

1 and IA32_EFER.LMA

THEN GP(new code segment selector); FI;

IF DPL > CPL

THEN #GP(new code segment selector); FI;

IF segment not present

THEN #NP(new code segment selector); FI;

IF stack not large enough for return address

THEN #SS(0); FI;

tempEIP ← DEST(Offset);

IF OperandSize

THEN