AMD Geode LX [email protected] User Manual
Page 651
AMD Geode™ LX Processors Data Book
651
Instruction Set
33234H
8.3.4.6
RSLDT - Restore Local Descriptor Table Register and Descriptor
Operation
Description
Restore the Local Descriptor Table 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 RSLDT instruction to be recognized.
The RSLDT instruction does not check its memory operand for validity. Care should be taken to always load valid data into
the LDT.
Opcode
Instruction
Clocks
Description
0F 7B
RSLDT m80
11
Restore LDTR 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
IF (CPL<>0 OR (SMM_INST_EN=0 AND SMM=0 AND DMM=0))
#UD;
ELSE
LDT.DESCR <= MEM80;