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IBM Personel Corn.puter MACRO Ass.rn.bler
Version 2.00
1-12
BIOSI
----
0&/10/85
INTERRUPT ISH BIOS ROUTINES
06-10-8S
135
PAGE
13.
137
THE FOLLOWING DIAGRAM DEPICTS THE ORGANIZATION
13.
OF GOT.
13'
;-----------------------------------------------------------------------------
,.0
;
GOT
;
,.2 '"
I
"3
I ••
IES,SII--»
.00
"5
i
j
DUMMY
,.7
".
.0.
1------
----------1
"6
I
GOT
I
I ••
1----------------1
150
• I 0
151
I
lOT
I
153
152
1----------------1
15.
I
os
I
155
1
1
15.
1----------------1
"7
I
ES
1
15.
15.
'.0
.2.
,.,
,.2
.30
I
~~~~~~~~~~~~~~~-
i
,.3
I.'
'.5
.3.
I---~~~;~~;~~----I
I ••
,.7
1
C5
1
I ••
1----------------1
I ••
;
170
I - - - ----- - ------ ---- - - - - - - - - - - - - - - ------------ - ---- - - - - - ---- -- -- - - - - - - - - ----- -
171
172
;
---- ---
-------- - - -
----------------
------ -
-
- - - -
-------------------
- ---
173
;
THE GL08AL DESCRIPTOR TABLE (ACTUAL LOCATION POINTED TO BY ES:S])
17.
1----- - - - - -------------------------- - ------- - - - - - ------------------ - - - - - - - - - --
175
17.
VIRTUAL ENABLE GOT DEF
STRUC
177 0000
-
-
DQ-
?
; FIRST DESCRIPTOR NOT ACCESSIBLE
178 oooe
GDTPTR
DO
;
GOT DESCRIPTOR
1790010
IDTPTR
DQ
;
lOT DESCR I PTOR
180 0018
USER
os
DO
, USER DATA SEGMENT DESCRIPTOR
lei
0020
USER-ES
DO
USER EXTRA SEGMENT OEseR I PTOR
182 0028
USER-55
DQ
USER STACK SEGMENT DESCRIPTOR
183 0030
USER-CS
DO
I USER CODE SEGMENT DESCR I PTOR
184 0038
BID CS
DQ
7
I
TEMPORARY 8105 DESCRIPTOR
1185 0040
V I RTUAL_ENABLE_GOT_DEF
ENDS
118&
ASSUME
OSIDATA
1188
118903FA
X VIRTUAL
PROC
FAR
1190 03FA
SET_VMOOE:
1191
1192
;-----
ENA8LE ADDRESS LATCH BIT 20
1193
119403FAFA
CLI
NO
I NTERRUPTS ALLOWED
1195 03FB 84 OF
"OV
AH,ENABLE B1T20
ENA8LE 81T 20 FOR ADDRESS GATE
1 19& 03FD E8 03CC R
CALL
GATE A20
1197 0400 3C 00
COP
AL,O-
WAS THE COMMAND ACCEPTED?
1198 0402 74 04
JZ
81T20 ON
GO IF YES
1199 040484 FF
MOV
AH,OFFH
SET THE ERROR FLAG
1200 0406 F9
5TC
SET CARRY
1201 0407 CF
IRET
EARLY EXIT
1202
" 87
1203
.0.
1204 0408
8IT20 ON:
1205 0408 06
-
PUSH
E5
; MOVE SEGMENT PO INTER
1206 0409 IF
05
i
TO THE OAT A SEGMENT
1207
1208
I
~---~~~~--
------------------------ - -
------------- - ----------- ------- - --
1209
; REINITIALIZE THE 8259 INTERRUPT CONTROLLER #1
TO THE USER SPECIFIED OFFSET
1210
;
-- - - - - - - - -
--
- - - - - -
-
-------- - - - - -
--
- -- - - - - - - - - - - - -
- --
- - -- - -
----
-
---
- - - - - - - - - - - -
1211
1212 040A 80 II
"OV
AL, I IH
START INITIALIZATION SEQUENCE-ICWI
1213 040C E6 20
OUT
INTAOO,AL
EDGE, INTERVAL-8.MASTER,ICW4 NEEDED
1214 040E E8 00
J"P
'.2
1215 0410 8A Cl
"OV
AL,8H
HARDWARE INT'S START AT
INT #
(8H]
1216 0412 E6 21
OUT
INTAOI,AL
SEND ICW2
1217 0414 E8 00
JMP
'.2
1218 041& 80 04
MOV
AL.04H
SEND ICW3 - MASTER LEVEL 2
1219 0418 E6 21
OUT
INTAOI,AL
1220 041A EB 00
.....
1·2
1221 041C BO 01
NOV
AL,OIH
SEND ICW4 - MASTER, 8086 MODE
1222 041E E& 21
OUT
iNTAOI,AL
1223 0420 EB 00
JMf'
1·2
1224 0422 BO FF
MOV
AL.OFFH
I MASK OFF ALL INTERRUPTS
1225 0424 E&
21
OUT
INTAOI.AL
122&
1227
;----------
- - - ------
---------------
- - -- ------- -- --
----------------
--- - -- -
----
1228
; RE I NIT
I
AL I ZE THE 8259
I
NTERRUPT CONTROLLER #2 TO THE USER SPEC I F I ED OFFSET
:
1229
;----------------------------------------------------------------------------
1230
1231 0426 80
I 1
"OV
AL, I IH
I N I TI AL I ZE SEQUENCE- I CW 1 FOR SLAVE
1232 0428 E6 AO
OUT
INTBOO.AL
EDGE,INTERVAL-8.MASTER,lCW4 NEEDED
1233 042A E8 00
JMP
1·2
1234 042C 8A C3
"OV
AL,BL
HARDWARE INT'S START AT
INT #
{8LI
1235 042E E6 AI
OUT
INT80l,AL
SEND ICW2
1236 0430 BO 02
MOV
AL.02H
1237 0432 EB 00
JMP
1·2
1238 0434 E6 A I
OUT
INTSO I ,AL
SEND ICW3 -
SLAVE LEVEL 2
1239 0436 EB 00
.-
1·2
1240 0438 BO 01
MOV
AL,OIH
1241 043A E6 AI
OUT
INTBOI,AL
I
SEND lCW4 -
SLAVE,8086 MODE
1242 043C EB 00
"M.
1·2
1243 043E BO FF
MOV
AL.OFFH
1244 0440 E& AI
OUT
INTBOI,AL
I MASK OFF ALL
INTERRUPTS
1245
1246
1---- --- ---- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1247
;
SETUP 810S CODE SEGMENT OESCR I PlOR
1248
5-174
BIOS1
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