AMD Geode™ LX Processors Data Book
653
Instruction Set
33234H
Notes
The RSM instruction does not check the values that it reads from the SMM header for validity.
The RSM instruction set the current privilege level to the SS DPL value read from the SMM header.
If a RSM restores the processor to real mode, the VM bit of the EFlags register is cleared regardless of the state of the VM
bit in the EFlags value of the SMM header.
If RSM restores the processor to a privilege level that is not 3, then the VM bit of the EFlags register is cleared, regardless
of the contents of the VM bit in the EFlags value of the SMM header.
8.3.4.8
RSTS - Restore Task Register and Descriptor
Operation
Description
Restore the Task register and descriptor from memory. Below is the format of the descriptor contents in memory.
Flags Affected
None.
Exceptions
#UD
If current privilege level is not 0, or the SMM_INST_EN = 0 and if the processor is not in SMM and if the processor
is not in DMM.
Notes
The
reg
field within the
mod r/m
byte must be zero for the RSTS instruction to be recognized.
The RSTS instruction does not check its memory operand for validity. Care should be taken to always load valid data into
the TS.
8.3.4.9
SETALC - Set AL to CF
Operation
AL <= {8{CF}};
Description
IF the EFlags CF is set, then the SETALC instruction sets AL to FFh. Otherwise, SETALC sets AL to FFh.
Flags Affected
None.
Opcode
Instruction
Clocks
Description
0F 7D
RSTS m80
12
Restore TS from memory
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
SELECTOR[15:3]
TI
RPL
+8
BASE[31:24]
G
B
0
V
LIMIT[19:16]
1
DPL
1
0
E
W
A
BASE[23:16]
+4
BASE[15:0]
LIMIT[15:0]
+0
Opcode
Instruction
Clocks
Description
d6
SETALC
2
Set AL according to CF.
IF (CPL<>0 OR (SMM_INST_EN=0 AND SMM=0 AND DMM=0))
#UD;
ELSE
TS.DESCR <= MEM80;
Summary of Contents for Geode LX 600
Page 14: ...14 AMD Geode LX Processors Data Book Overview 33234H...
Page 20: ...20 AMD Geode LX Processors Data Book Architecture Overview 33234H...
Page 44: ...44 AMD Geode LX Processors Data Book Signal Definitions 33234H...
Page 88: ...88 AMD Geode LX Processors Data Book GLIU Register Descriptions 33234H...
Page 618: ...618 AMD Geode LX Processors Data Book Electrical Specifications 33234H...