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2288 clevermous 1
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
2
;;                                                              ;;
5363 yogev_ezra 3
;; Copyright (C) KolibriOS team 2004-2015. All rights reserved. ;;
2288 clevermous 4
;; Copyright (C) MenuetOS 2000-2004 Ville Mikael Turjanmaa      ;;
5
;; Distributed under terms of the GNU General Public License    ;;
6
;;                                                              ;;
7
;;  BOOTCODE.INC                                                ;;
8
;;                                                              ;;
9
;;  KolibriOS 16-bit loader,                                    ;;
10
;;                        based on bootcode for MenuetOS        ;;
11
;;                                                              ;;
12
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
13
 
14
$Revision: 7129 $
15
 
16
 
17
;==========================================================================
18
;
19
;                           16 BIT FUNCTIONS
20
;
21
;==========================================================================
22
 
23
 
24
putchar:
25
; in: al=character
26
        mov     ah, 0Eh
27
        mov     bh, 0
28
        int     10h
29
        ret
30
 
31
print:
32
; in: si->string
33
        mov     al, 186
34
        call    putchar
35
        mov     al, ' '
36
        call    putchar
37
 
38
printplain:
39
; in: si->string
40
        pusha
41
        lodsb
42
@@:
43
        call    putchar
44
        lodsb
45
        test    al, al
46
        jnz     @b
47
        popa
48
        ret
49
 
3796 yogev_ezra 50
getkey:                         ; Use BIOS INT 16h to read a key from the keyboard
2288 clevermous 51
; get number in range [bl,bh] (bl,bh in ['0'..'9'])
52
; in: bx=range
53
; out: ax=digit (1..9, 10 for 0)
3989 yogev_ezra 54
        mov     ah, 0       ; If 'int 16h' is called with 'ah' equal to zero, the BIOS will not return control to the caller
55
        int     16h         ; until a key is available in the system type ahead buffer. On return, 'al' contains the ASCII
56
        cmp     al, 27      ; code for the key read from the buffer and 'ah' contains the keyboard scan code. (27=>ESC)
57
        jz      @f          ; If ESC is pressed, return (user doesn't want to change any value).
58
        cmp     al, bl      ; Compare 'al' (ASCII code of key pressed) with 'bl' (lowest accepted char from the range).
59
        jb      getkey      ; ASCII code is below lowest accepted value => continue waiting for another key.
60
        cmp     al, bh      ; Compare 'al' (ASCII code of key pressed) with 'bh' (highest accepted char from the range).
61
        ja      getkey      ; ASCII code is above highest accepted value => continue waiting for another key.
62
        push    ax          ; If the pressed key is in the accepted range, save it on the stack and echo to screen.
2288 clevermous 63
        call    putchar
64
        pop     ax
3989 yogev_ezra 65
        and     ax, 0Fh     ; Convert ASCII code to number: '1'->1, '2'->2, etc. 0Fh=1111b.
66
        jnz     @f          ; ASCII code for '0' is 48 (110000b). (110000b AND 1111b) = 0
67
        mov     al, 10      ; So if key '0' was entered, return 10 in 'ax'
2288 clevermous 68
@@:
69
        ret
70
 
71
setcursor:
72
; in: dl=column, dh=row
73
        mov     ah, 2
74
        mov     bh, 0
75
        int     10h
76
        ret
77
 
78
macro _setcursor row,column
79
{
80
        mov     dx, row*256 + column
81
        call    setcursor
82
}
83
 
3989 yogev_ezra 84
macro _ask_question question,range,variable_to_set
85
{
86
        _setcursor 16,0
87
        mov     si, question    ; Print the question
88
        call    print
89
        mov     bx, range       ; range accepted for answer
90
        call    getkey
91
        cmp     al, 27          ; If ESC was pressed, do not change the value
92
        jz      .esc_pressed
93
        mov     [variable_to_set], al
94
}
95
 
2288 clevermous 96
boot_read_floppy:
97
        push    si
98
        xor     si, si
99
        mov     ah, 2   ; read
100
@@:
101
        push    ax
102
        int     0x13
103
        pop     ax
104
        jnc     @f
105
        inc     si
106
        cmp     si, 10
107
        jb      @b
108
sayerr_badsect:
109
        mov     si, badsect
110
sayerr_plain:
111
        call    printplain
112
        jmp     $
113
@@:
114
        pop     si
115
        ret
116
 
117
; convert abs. sector number (AX) to BIOS T:H:S
118
; sector number = (abs.sector%BPB_SecPerTrk)+1
119
; pre.track number = (abs.sector/BPB_SecPerTrk)
120
; head number = pre.track number%BPB_NumHeads
121
; track number = pre.track number/BPB_NumHeads
122
; Return: cl - sector number
123
;         ch - track number
124
;         dl - drive number (0 = a:)
125
;         dh - head number
126
conv_abs_to_THS:
127
        push    bx
128
        mov     bx, word [BPB_SecPerTrk]
129
        xor     dx, dx
130
        div     bx
131
        inc     dx
132
        mov     cl, dl                          ; cl = sector number
133
        mov     bx, word [BPB_NumHeads]
134
        xor     dx, dx
135
        div     bx
136
        ; !!!!!!! ax = track number, dx = head number
137
        mov     ch, al                          ; ch=track number
138
        xchg    dh, dl                          ; dh=head number
139
        mov     dl, 0                           ; dl=0 (drive 0 (a:))
140
        pop     bx
141
        retn
142
; needed variables
143
BPB_SecPerTrk   dw      0                       ; sectors per track
144
BPB_NumHeads    dw      0                       ; number of heads
145
BPB_FATSz16     dw      0                       ; size of FAT
146
BPB_RootEntCnt  dw      0                       ; count of root dir. entries
147
BPB_BytsPerSec  dw      0                       ; bytes per sector
148
BPB_RsvdSecCnt  dw      0                       ; number of reserved sectors
149
BPB_TotSec16    dw      0                       ; count of the sectors on the volume
150
BPB_SecPerClus  db      0                       ; number of sectors per cluster
151
BPB_NumFATs     db      0                       ; number of FAT tables
152
abs_sector_adj  dw      0                       ; adjustment to make abs. sector number
153
end_of_FAT      dw      0                       ; end of FAT table
154
FirstDataSector dw      0                       ; begin of data
155
 
156
;=========================================================================
157
;
158
;                           16 BIT CODE
159
;
160
;=========================================================================
161
 
5786 serge 162
include 'bootvesa.inc'                 ;Include source for boot vesa
2288 clevermous 163
if defined extended_primary_loader
164
include 'parsers.inc'
165
end if
166
 
167
start_of_code:
168
 
169
if defined extended_primary_loader
170
; save data from primary loader
171
        mov     word [cs:bootcallback], si
172
        mov     word [cs:bootcallback+2], ds
173
        push    cs
174
        pop     ds
175
        mov     [bootdevice], ax
176
        mov     [bootfs], bx
177
 
178
; set up stack
5790 serge 179
        mov     ax, (TMP_STACK_TOP and 0xF0000) shr 4
2288 clevermous 180
        mov     ss, ax
5786 serge 181
        mov     sp, TMP_STACK_TOP and 0xFFFF
2288 clevermous 182
 
183
; try to load configuration file
184
        mov     ax, 1
185
        mov     di, config_file_struct
186
        call    [bootcallback]
187
        cld
188
        push    cs
189
        pop     es
190
; bx=0 - ok, bx=1 - part of file loaded, assume this is ok
191
        cmp     bx, 1
192
        ja      .config_bad
193
; configuration file was loaded, parse
194
; if length is too big, use first 0FFFFh bytes
195
        test    dx, dx
196
        jz      @f
197
        mov     ax, 0FFFFh
198
@@:
199
; ds:si will be pointer to current data, dx = limit
200
        xchg    ax, dx
201
        push    4000h
202
        pop     ds
203
        xor     si, si
204
.parse_loop:
205
; skip spaces
206
        cmp     si, dx
207
        jae     .parse_done
208
        lodsb
209
        cmp     al, ' '
210
        jbe     .parse_loop
211
        dec     si
212
; loop over all possible configuration values
213
        mov     bx, config_file_variables
214
.find_variant:
215
; get length
216
        mov     cx, [es:bx]
217
; zero length = end of list
218
        jecxz   .find_newline
219
; skip over length
220
        inc     bx
221
        inc     bx
222
        mov     di, bx
223
; skip over string
224
        add     bx, cx
225
; test whether we have at least cx symbols left
226
        mov     ax, cx
227
        add     ax, si
228
        jc      .next_variant1
229
        cmp     ax, dx
230
        jae     .next_variant1
231
; save current position
232
        push    si
233
; compare strings
234
        repz cmpsb
235
        jnz     .next_variant2
236
; strings are equal; look for "=" with possible spaces before and after
237
@@:
238
        cmp     si, dx
239
        jae     .next_variant2
240
        lodsb
241
        cmp     al, ' '
242
        jbe     @b
243
        cmp     al, '='
244
        jnz     .next_variant2
245
; ok, we found the true variant
246
; ignore saved position on the stack
247
        pop     ax
248
; call the parser
249
        call    word [es:bx]
250
; line parsed, find next
251
.find_newline:
252
        cmp     si, dx
253
        jae     .parse_done
254
        lodsb
255
        cmp     al, 13
256
        jz      .parse_loop
257
        cmp     al, 10
258
        jz      .parse_loop
259
        jmp     .find_newline
260
.next_variant2:
261
; continue to the next variant, restoring current position
262
        pop     si
263
.next_variant1:
264
; continue to the next variant
265
; skip over the parser
266
        inc     bx
267
        inc     bx
268
        jmp     .find_variant
269
.parse_done:
270
.config_bad:
271
 
272
; set up segment registers
273
        push    cs
274
        pop     ds
275
else
276
        cld
7129 dunkaist 277
        push    0
278
        pop     es
2288 clevermous 279
; \begin{diamond}[02.12.2005]
280
; if bootloader sets ax = 'KL', then ds:si points to loader block
281
        cmp     ax, 'KL'
282
        jnz     @f
283
        mov     word [cs:cfgmanager.loader_block], si
284
        mov     word [cs:cfgmanager.loader_block+2], ds
7129 dunkaist 285
        mov     word [es:BOOT_KERNEL_RESTART], kernel_restart_bootblock
2288 clevermous 286
@@:
287
; \end{diamond}[02.12.2005]
288
 
7129 dunkaist 289
; if bootloader sets cx = 'HA' and dx = 'RD', then bx contains identifier of source disk
290
; (see comment to BOOT_BX_FROM_LOAD and loader_doc.txt)
291
        mov     word [es:BOOT_BX_FROM_LOAD], 'r1'  ; default value: /rd/1
2288 clevermous 292
        cmp     cx, 'HA'
293
        jnz     no_hd_load
294
        cmp     dx, 'RD'
295
        jnz     no_hd_load
7129 dunkaist 296
        mov     [es:BOOT_BX_FROM_LOAD], bx
2288 clevermous 297
no_hd_load:
298
 
299
; set up stack
5790 serge 300
        mov     ax, (TMP_STACK_TOP and 0xF0000) shr 4
2288 clevermous 301
        mov     ss, ax
5786 serge 302
        mov     sp, TMP_STACK_TOP and 0xFFFF
2288 clevermous 303
; set up segment registers
304
        push    cs
305
        pop     ds
306
        push    cs
307
        pop     es
308
end if
309
 
310
; set videomode
311
        mov     ax, 3
312
        int     0x10
313
 
314
if lang eq ru
315
 ; Load & set russian VGA font (RU.INC)
316
        mov     bp, RU_FNT1             ; RU_FNT1 - First part
317
        mov     bx, 1000h               ; 768 bytes
318
        mov     cx, 30h                 ; 48 symbols
319
        mov     dx, 80h                 ; 128 - position of first symbol
320
        mov     ax, 1100h
321
        int     10h
322
 
323
        mov     bp, RU_FNT2             ; RU_FNT2 -Second part
324
        mov     bx, 1000h               ; 512 bytes
325
        mov     cx, 20h                 ; 32 symbols
326
        mov     dx, 0E0h                ; 224 - position of first symbol
327
        mov     ax, 1100h
328
        int     10h
329
 ; End set VGA russian font
330
else if lang eq et
331
        mov     bp, ET_FNT              ; ET_FNT1
332
        mov     bx, 1000h               ;
333
        mov     cx, 255                 ; 256 symbols
334
        xor     dx, dx                  ; 0 - position of first symbol
335
        mov     ax, 1100h
336
        int     10h
337
end if
338
 
339
; draw frames
340
        push    0xb800
341
        pop     es
342
        xor     di, di
343
        mov     ah, 1*16+15
344
 
345
; draw top
346
        mov     si, d80x25_top
347
        mov     cx, d80x25_top_num * 80
348
@@:
349
        lodsb
350
        stosw
351
        loop    @b
352
; draw spaces
353
        mov     si, space_msg
354
        mov     dx, 25 - d80x25_top_num - d80x25_bottom_num
355
dfl1:
356
        push    si
357
        mov     cx, 80
358
@@:
359
        lodsb
360
        stosw
361
        loop    @b
362
        pop     si
363
        dec     dx
364
        jnz     dfl1
365
; draw bottom
366
        mov     si, d80x25_bottom
367
        mov     cx, d80x25_bottom_num * 80
368
@@:
369
        lodsb
370
        stosw
371
        loop    @b
372
 
373
        mov     byte [space_msg+80], 0    ; now space_msg is null terminated
374
 
375
        _setcursor d80x25_top_num,0
376
 
377
 
378
; TEST FOR 386+
379
 
380
        mov     bx, 0x4000
381
        pushf
382
        pop     ax
383
        mov     dx, ax
384
        xor     ax, bx
385
        push    ax
386
        popf
387
        pushf
388
        pop     ax
389
        and     ax, bx
390
        and     dx, bx
391
        cmp     ax, dx
392
        jnz     cpugood
393
        mov     si, not386
394
sayerr:
395
        call    print
396
        jmp     $
397
     cpugood:
398
 
399
        push    0
400
        popf
401
 
402
; set up esp
403
        movzx   esp, sp
404
 
405
        push    0
406
        pop     es
3774 mario79 407
 
5012 clevermous 408
        xor     cx, cx
409
@@:
410
        in      al, 64h
411
        test    al, 2
412
        loopnz  @b
413
 
3539 clevermous 414
        mov     al, 0xf6        ; Сброс клавиатуры, разрешить сканирование
2288 clevermous 415
        out     0x60, al
416
        xor     cx, cx
5012 clevermous 417
@@:
2288 clevermous 418
        in      al, 64h
5012 clevermous 419
        test    al, 1
5028 clevermous 420
        loopz   @b
5012 clevermous 421
        in      al, 0x60
2288 clevermous 422
 
423
;;;/diamond today   5.02.2008
424
; set keyboard typematic rate & delay
425
        mov     al, 0xf3
426
        out     0x60, al
427
        xor     cx, cx
428
@@:
429
        in      al, 64h
5012 clevermous 430
        test    al, 1
5028 clevermous 431
        loopz   @b
5012 clevermous 432
        in      al, 0x60
2288 clevermous 433
        mov     al, 0
434
        out     0x60, al
435
        xor     cx, cx
436
@@:
437
        in      al, 64h
5012 clevermous 438
        test    al, 1
5028 clevermous 439
        loopz   @b
5012 clevermous 440
        in      al, 0x60
2288 clevermous 441
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
5012 clevermous 442
        sti
2288 clevermous 443
; --------------- APM ---------------------
2466 Serge 444
        and     word [es:BOOT_APM_VERSION], 0     ; ver = 0.0 (APM not found)
2288 clevermous 445
        mov     ax, 0x5300
446
        xor     bx, bx
447
        int     0x15
448
        jc      apm_end                 ; APM not found
449
        test    cx, 2
450
        jz      apm_end                 ; APM 32-bit protected-mode interface not supported
2466 Serge 451
        mov     [es:BOOT_APM_VERSION], ax         ; Save APM Version
452
        mov     [es:BOOT_APM_FLAGS], cx           ; Save APM flags
2288 clevermous 453
 
454
        ; Write APM ver ----
455
        and     ax, 0xf0f
456
        add     ax, '00'
457
        mov     si, msg_apm
458
        mov     [si + 5], ah
459
        mov     [si + 7], al
460
        _setcursor 0, 3
461
        call    printplain
462
        ; ------------------
463
 
464
        mov     ax, 0x5304              ; Disconnect interface
465
        xor     bx, bx
466
        int     0x15
467
        mov     ax, 0x5303              ; Connect 32 bit mode interface
468
        xor     bx, bx
469
        int     0x15
470
 
2466 Serge 471
        mov     [es:BOOT_APM_ENTRY], ebx
472
        mov     [es:BOOT_APM_CODE_32], ax
473
        mov     [es:BOOT_APM_CODE_16], cx
474
        mov     [es:BOOT_APM_DATA_16], dx
2288 clevermous 475
 
476
apm_end:
477
        _setcursor d80x25_top_num, 0
478
 
479
if ~ defined extended_primary_loader
480
;CHECK current of code
481
        cmp     [cfgmanager.loader_block], -1
482
        jz      noloaderblock
483
        les     bx, [cfgmanager.loader_block]
484
        cmp     byte [es:bx], 1
485
        mov     si, loader_block_error
486
        jnz     sayerr
487
        push    0
488
        pop     es
489
end if
490
 
491
noloaderblock:
492
; DISPLAY VESA INFORMATION
493
        call    print_vesa_info
494
        call    calc_vmodes_table
495
        call    check_first_parm   ;check and enable cursor_pos
496
 
497
; \begin{diamond}[30.11.2005]
498
cfgmanager:
499
; settings:
500
; a) preboot_graph = graphical mode
501
;    preboot_gprobe = probe this mode?
3777 yogev_ezra 502
; b) preboot_biosdisk  = use BIOS disks through V86 emulation? // (earlier was: preboot_dma  = use DMA access?)
7121 dunkaist 503
; c) preboot_debug = duplicates kernel debug output to the screen
3777 yogev_ezra 504
; d) preboot_launcher = start the first app (right now it's LAUNCHER) after kernel is loaded?
505
; e) preboot_device = from where to boot?
2288 clevermous 506
 
507
; determine default settings
508
if ~ defined extended_primary_loader
509
        mov     [.bSettingsChanged], 0
510
end if
511
 
512
;.preboot_gr_end:
513
        mov     di, preboot_device
514
; if image in memory is present and [preboot_device] is uninitialized,
515
; set it to use this preloaded image
516
        cmp     byte [di], 0
517
        jnz     .preboot_device_inited
518
if defined extended_primary_loader
519
        inc     byte [di]
520
        cmp     byte [bootdevice], 'f' ; floppy?
521
        jz      .preboot_device_inited
522
        inc     byte [di]
523
else
524
        cmp     [.loader_block], -1
525
        jz      @f
526
        les     bx, [.loader_block]
527
        test    byte [es:bx+1], 1
528
        jz      @f
529
        mov     byte [di], 3
530
        jmp     .preboot_device_inited
531
@@:
532
; otherwise, set [preboot_device] to 1 (default value - boot from floppy)
533
        mov     byte [di], 1
534
end if
535
.preboot_device_inited:
536
; following 4 lines set variables to 1 if its current value is 0
537
        cmp     byte [di+preboot_dma-preboot_device], 1
538
        adc     byte [di+preboot_dma-preboot_device], 0
3777 yogev_ezra 539
        cmp     byte [di+preboot_launcher-preboot_device], 1        ; Start LAUNCHER by default
5786 serge 540
        adc     byte [di+preboot_launcher-preboot_device], 0
2288 clevermous 541
        _setcursor 5,2
542
 
543
        mov     si, linef
544
        call    printplain
545
        mov     si, start_msg
546
        call    print
547
        mov     si, time_msg
548
        call    print
549
; get start time
550
        call    .gettime
551
        mov     [.starttime], eax
552
        mov     word [.timer], .newtimer
553
        mov     word [.timer+2], cs
554
.printcfg:
555
 
556
        _setcursor 9,0
557
        mov     si, current_cfg_msg
558
        call    print
559
        mov     si, curvideo_msg
560
        call    print
561
 
562
        call    draw_current_vmode
563
 
564
        mov     si, usebd_msg
565
        cmp     [preboot_biosdisk], 1
566
        call    .say_on_off
3777 yogev_ezra 567
        mov     si, debug_mode_msg
568
        cmp     [preboot_debug], 1
569
        call    .say_on_off
570
        mov     si, launcher_msg
571
        cmp     [preboot_launcher], 1
572
        call    .say_on_off
2288 clevermous 573
        mov     si, preboot_device_msg
574
        call    print
575
        mov     al, [preboot_device]
576
if defined extended_primary_loader
577
        and     eax, 3
578
else
579
        and     eax, 7
580
end if
581
        mov     si, [preboot_device_msgs+eax*2]
582
        call    printplain
583
.show_remarks:
584
; show remarks in gray color
585
        mov     di, ((21-num_remarks)*80 + 2)*2
586
        push    0xB800
587
        pop     es
588
        mov     cx, num_remarks
589
        mov     si, remarks
590
.write_remarks:
591
        lodsw
592
        push    si
593
        xchg    ax, si
594
        mov     ah, 1*16+7      ; background: blue (1), foreground: gray (7)
595
        push    di
596
.write_remark:
597
        lodsb
598
        test    al, al
599
        jz      @f
600
        stosw
601
        jmp     .write_remark
602
@@:
603
        pop     di
604
        pop     si
605
        add     di, 80*2
606
        loop    .write_remarks
607
.wait:
608
        _setcursor 25,0         ; out of screen
609
; set timer interrupt handler
610
        cli
611
        push    0
612
        pop     es
613
        push    dword [es:8*4]
614
        pop     dword [.oldtimer]
615
        push    dword [.timer]
616
        pop     dword [es:8*4]
617
;        mov     eax, [es:8*4]
618
;        mov     [.oldtimer], eax
619
;        mov     eax, [.timer]
620
;        mov     [es:8*4], eax
621
        sti
622
; wait for keypressed
623
        xor     ax, ax
624
        int     16h
625
        push    ax
626
; restore timer interrupt
627
;        push    0
628
;        pop     es
629
        mov     eax, [.oldtimer]
630
        mov     [es:8*4], eax
631
        mov     [.timer], eax
632
 
633
        _setcursor 7,0
634
        mov     si, space_msg
635
        call    printplain
636
; clear remarks and restore normal attributes
637
        push    es
638
        mov     di, ((21-num_remarks)*80 + 2)*2
639
        push    0xB800
640
        pop     es
641
        mov     cx, num_remarks
642
        mov     ax, ' ' + (1*16 + 15)*100h
643
@@:
644
        push    cx
645
        mov     cx, 76
646
        rep stosw
647
        pop     cx
648
        add     di, 4*2
649
        loop    @b
650
        pop     es
651
        pop     ax
652
; switch on key
653
        cmp     al, 13
654
        jz      .continue
655
        or      al, 20h
3777 yogev_ezra 656
        cmp     al, 'a'         ; select graphical mode
2288 clevermous 657
        jz      .change_a
3760 hidnplayr 658
        cmp     al, 'q'         ; Trick to make 'A' key on azerty keyboard work
659
        je      .change_a
3777 yogev_ezra 660
        cmp     al, 'b'         ; use BIOS disks? // (selecting YES will make BIOS disks visible as /bd)
2288 clevermous 661
        jz      .change_b
7121 dunkaist 662
        cmp     al, 'c'         ; load kernel in debug mode?
3777 yogev_ezra 663
        jz      .change_c
664
        cmp     al, 'd'         ; start launcher after kernel is loaded?
665
        jz      .change_d
666
        cmp     al, 'e'         ; select boot origin
2288 clevermous 667
        jnz     .show_remarks
3777 yogev_ezra 668
; e) preboot_device = from where to boot?
2288 clevermous 669
if defined extended_primary_loader
3989 yogev_ezra 670
        _ask_question bdev,'12',preboot_device              ; range accepted for answer: 1-2
2288 clevermous 671
else
3989 yogev_ezra 672
        _ask_question bdev,'14',preboot_device              ; range accepted for answer: 1-4
5786 serge 673
end if
3777 yogev_ezra 674
        _setcursor 14,0
3989 yogev_ezra 675
 
2288 clevermous 676
.d:
677
if ~ defined extended_primary_loader
678
        mov     [.bSettingsChanged], 1
679
end if
3989 yogev_ezra 680
.esc_pressed:
2288 clevermous 681
        call    clear_vmodes_table             ;clear vmodes_table
682
        jmp     .printcfg
3989 yogev_ezra 683
 
2288 clevermous 684
.change_a:
3797 mario79 685
        call    clear_vmodes_table             ;clear vmodes_table
3999 mario79 686
 
687
        mov     si, word [cursor_pos]
688
        mov     word [cursor_pos_old], si
2288 clevermous 689
.loops:
690
        call    draw_vmodes_table
691
        _setcursor 25,0         ; out of screen
692
        xor     ax, ax
693
        int     0x16
694
;        call    clear_table_cursor             ;clear current position of cursor
695
 
696
        mov     si, word [cursor_pos]
697
 
3989 yogev_ezra 698
        cmp     al, 27              ; If ESC was pressed, do not change the value
3999 mario79 699
        jnz     @f                   ; Just exit the resolution selection box
700
 
701
        mov     si, word [cursor_pos_old]
702
        mov     word [cursor_pos], si
703
        jmp     .esc_pressed
704
@@:
2288 clevermous 705
        cmp     ah, 0x48;x,0x48E0               ; up
706
        jne     .down
707
        cmp     si, modes_table
708
        jbe     .loops
709
        sub     word [cursor_pos], size_of_step
710
        jmp     .loops
711
 
712
.down:
713
        cmp     ah, 0x50;x,0x50E0               ; down
714
        jne     .pgup
715
        cmp     word[es:si+10], -1
716
        je      .loops
717
        add     word [cursor_pos], size_of_step
718
        jmp     .loops
719
 
720
.pgup:
721
        cmp     ah, 0x49                ; page up
722
        jne     .pgdn
723
        sub     si, size_of_step*long_v_table
724
        cmp     si, modes_table
725
        jae     @f
726
        mov     si, modes_table
727
@@:
728
        mov     word [cursor_pos], si
729
        mov     si, word [home_cursor]
730
        sub     si, size_of_step*long_v_table
731
        cmp     si, modes_table
732
        jae     @f
733
        mov     si, modes_table
734
@@:
735
        mov     word [home_cursor], si
736
        jmp     .loops
737
 
738
.pgdn:
739
        cmp     ah, 0x51                ; page down
740
        jne     .enter
741
        mov     ax, [end_cursor]
742
        add     si, size_of_step*long_v_table
743
        cmp     si, ax
744
        jb      @f
745
        mov     si, ax
746
        sub     si, size_of_step
747
@@:
748
        mov     word [cursor_pos], si
749
        mov     si, word [home_cursor]
750
        sub     ax, size_of_step*long_v_table
751
        add     si, size_of_step*long_v_table
752
        cmp     si, ax
753
        jb      @f
754
        mov     si, ax
755
@@:
756
        mov     word [home_cursor], si
757
        jmp     .loops
758
 
759
.enter:
760
        cmp     al, 0x0D;x,0x1C0D               ; enter
761
        jne     .loops
762
        push    word [cursor_pos]
763
        pop     bp
764
        push    word [es:bp]
765
        pop     word [x_save]
766
        push    word [es:bp+2]
767
        pop     word [y_save]
768
        push    word [es:bp+6]
769
        pop     word [number_vm]
770
        mov     word [preboot_graph], bp          ;save choose
771
 
772
        jmp     .d
773
 
3777 yogev_ezra 774
.change_b:                      ; b) preboot_biosdisk  = use BIOS disks through V86 emulation?
3989 yogev_ezra 775
;        _setcursor 16,0
3777 yogev_ezra 776
;        mov     si, ask_dma    // (earlier was: preboot_dma  = use DMA access?)
2288 clevermous 777
;        call    print
3796 yogev_ezra 778
;        mov     bx, '13'       ; range accepted for answer: 1-3
2288 clevermous 779
;        call    getkey
780
;        mov     [preboot_dma], al
3989 yogev_ezra 781
        _ask_question ask_bd,'12',preboot_biosdisk              ; range accepted for answer: 1-2
2288 clevermous 782
        _setcursor 11,0
783
        jmp     .d
3796 yogev_ezra 784
.change_c:                      ; c) preboot_debug = duplicates kernel debug output to the screen
3989 yogev_ezra 785
        _ask_question ask_debug,'12',preboot_debug              ; range accepted for answer: 1-2
3777 yogev_ezra 786
        _setcursor 12,0
787
        jmp     .d
3796 yogev_ezra 788
.change_d:                      ; d) preboot_launcher = start the first app (right now it's LAUNCHER) after kernel is loaded?
3989 yogev_ezra 789
        _ask_question ask_launcher,'12',preboot_launcher        ; range accepted for answer: 1-2
3777 yogev_ezra 790
        _setcursor 13,0
791
        jmp     .d
2288 clevermous 792
;;;;;;;;;;;;;;;;;;;;;;;;;;;;
793
.say_on_off:
794
        pushf
795
        call    print
796
        mov     si, on_msg
797
        popf
798
        jz      @f
799
        mov     si, off_msg
800
@@:
801
        jmp     printplain
802
; novesa and vervesa strings are not used at the moment of executing this code
803
virtual at novesa
804
.oldtimer dd ?
805
.starttime dd ?
806
if ~ defined extended_primary_loader
807
.bSettingsChanged db ?
808
end if
809
.timer dd ?
810
end virtual
811
if ~ defined extended_primary_loader
812
.loader_block dd -1
813
end if
814
.gettime:
815
        mov     ah, 0
816
        int     1Ah
817
        xchg    ax, cx
818
        shl     eax, 10h
819
        xchg    ax, dx
820
        ret
821
.newtimer:
822
        push    ds
823
        push    cs
824
        pop     ds
825
        pushf
826
        call    [.oldtimer]
827
        pushad
828
        call    .gettime
829
        sub     eax, [.starttime]
830
if defined extended_primary_loader
831
        sub     ax, [preboot_timeout]
832
else
833
        sub     ax, 18*5
834
end if
835
        jae     .timergo
836
        neg     ax
837
        add     ax, 18-1
838
        mov     bx, 18
839
        xor     dx, dx
840
        div     bx
841
if lang eq ru
3539 clevermous 842
; подождите 5 секунд, 4/3/2 секунды, 1 секунду
2288 clevermous 843
        cmp     al, 5
844
        mov     cl, ' '
845
        jae     @f
846
        cmp     al, 1
3539 clevermous 847
        mov     cl, 0xE3 ; 'у' in cp866
2288 clevermous 848
        jz      @f
3539 clevermous 849
        mov     cl, 0xEB ; 'ы' in cp866
2288 clevermous 850
@@:
851
        mov     [time_str+9], cl
852
else if lang eq et
853
        cmp     al, 1
854
        ja      @f
3539 clevermous 855
        mov     byte [time_str+9], ' '
856
        mov     byte [time_str+10], ' '
2288 clevermous 857
@@:
3274 esevece 858
else if lang eq sp
859
; esperar 5/4/3/2 segundos, 1 segundo
860
        cmp     al, 1
861
        mov     cl, 's'
862
        ja      @f
863
        mov     cl, ' '
864
@@:
865
        mov     [time_str+10], cl
2288 clevermous 866
else
867
; wait 5/4/3/2 seconds, 1 second
868
        cmp     al, 1
869
        mov     cl, 's'
870
        ja      @f
871
        mov     cl, ' '
872
@@:
873
        mov     [time_str+9], cl
874
end if
875
        add     al, '0'
876
        mov     [time_str+1], al
877
        mov     si, time_msg
878
        _setcursor 7,0
879
        call    print
880
        _setcursor 25,0
881
        popad
882
        pop     ds
883
        iret
884
.timergo:
885
        push    0
886
        pop     es
887
        mov     eax, [.oldtimer]
888
        mov     [es:8*4], eax
889
        mov     sp, 0EC00h
890
.continue:
891
        sti
892
        _setcursor 6,0
893
        mov     si, space_msg
894
        call    printplain
895
        call    printplain
896
        _setcursor 6,0
897
        mov     si, loading_msg
898
        call    print
3777 yogev_ezra 899
        _setcursor 16,0
2288 clevermous 900
if ~ defined extended_primary_loader
901
        cmp     [.bSettingsChanged], 0
902
        jz      .load
903
        cmp     [.loader_block], -1
904
        jz      .load
905
        les     bx, [.loader_block]
906
        mov     eax, [es:bx+3]
907
        push    ds
908
        pop     es
909
        test    eax, eax
910
        jz      .load
911
        push    eax
912
        mov     si, save_quest
913
        call    print
914
.waityn:
915
        mov     ah, 0
916
        int     16h
917
        or      al, 20h
918
        cmp     al, 'n'
919
        jz      .loadc
3430 esevece 920
        if lang eq sp
921
        cmp     al, 's'
922
        else
2288 clevermous 923
        cmp     al, 'y'
3430 esevece 924
        end if
2288 clevermous 925
        jnz     .waityn
926
        call    putchar
927
        mov     byte [space_msg+80], 186
928
 
929
        pop     eax
930
        push    cs
931
        push    .cont
932
        push    eax
933
        retf                          ;call back
934
.loadc:
935
        pop     eax
936
.cont:
937
        push    cs
938
        pop     ds
939
        mov     si, space_msg
940
        mov     byte [si+80], 0
3777 yogev_ezra 941
        _setcursor 16,0
2288 clevermous 942
        call    printplain
3777 yogev_ezra 943
        _setcursor 16,0
2288 clevermous 944
.load:
945
end if
946
; \end{diamond}[02.12.2005]
947
 
948
; ASK GRAPHICS MODE
949
 
950
        call    set_vmode
951
 
952
; GRAPHICS ACCELERATION
953
; force yes
2466 Serge 954
        mov     [es:BOOT_MTRR], byte 1
2288 clevermous 955
 
956
; DMA ACCESS TO HD
957
 
958
        mov     al, [preboot_dma]
2466 Serge 959
        mov     [es:BOOT_DMA], al
2288 clevermous 960
 
3777 yogev_ezra 961
; Set kernel DEBUG mode - if nonzero, duplicates debug output to the screen.
962
        mov     al, [preboot_debug]
963
        mov     [es:BOOT_DEBUG_PRINT], al       ;// 0x901E
964
 
965
; Start the first app (right now it's LAUNCHER) after kernel is loaded?
966
        mov     al, [preboot_launcher]
967
        mov     [es:BOOT_LAUNCHER_START], al    ;// 0x901D
968
 
2288 clevermous 969
; BOOT DEVICE
970
 
971
        mov     al, [preboot_device]
972
        dec     al
7129 dunkaist 973
        mov     [es:BOOT_DEV], al
2288 clevermous 974
 
975
; GET MEMORY MAP
976
include '../detect/biosmem.inc'
977
 
978
; READ DISKETTE TO MEMORY
979
 
7129 dunkaist 980
        cmp     byte [es:BOOT_DEV], 0
2288 clevermous 981
        jne     no_sys_on_floppy
982
        mov     si, diskload
983
        call    print
984
        xor     ax, ax            ; reset drive
985
        xor     dx, dx
986
        int     0x13
987
; do we boot from CD-ROM?
988
        mov     ah, 41h
989
        mov     bx, 55AAh
990
        xor     dx, dx
991
        int     0x13
992
        jc      .nocd
993
        cmp     bx, 0AA55h
994
        jnz     .nocd
995
        mov     ah, 48h
996
        push    ds
997
        push    es
998
        pop     ds
999
        mov     si, 0xa000
1000
        mov     word [si], 30
1001
        int     0x13
1002
        pop     ds
1003
        jc      .nocd
1004
        push    ds
1005
        lds     si, [es:si+26]
1006
        test    byte [ds:si+10], 40h
1007
        pop     ds
1008
        jz      .nocd
1009
; yes - read all floppy by 18 sectors
1010
 
1011
; TODO: !!!! read only first sector and set variables !!!!!
1012
; ...
1013
; TODO: !!! then read flippy image track by track
1014
 
1015
        mov     cx, 0x0001      ; startcyl,startsector
1016
.a1:
1017
        push    cx dx
1018
        mov     al, 18
1019
        mov     bx, 0xa000
1020
        call    boot_read_floppy
1021
        mov     si, movedesc
1022
        push    es
1023
        push    ds
1024
        pop     es
1025
        mov     cx, 256*18
1026
        mov     ah, 0x87
1027
        int     0x15
1028
        pop     es
1029
        pop     dx cx
1030
        test    ah, ah
1031
        jnz     sayerr_floppy
1032
        add     dword [si+8*3+2], 512*18
1033
        inc     dh
1034
        cmp     dh, 2
1035
        jnz     .a1
1036
        mov     dh, 0
1037
        inc     ch
1038
        cmp     ch, 80
1039
        jae     ok_sys_on_floppy
1040
        pusha
1041
        mov     al, ch
1042
        shr     ch, 2
1043
        add     al, ch
1044
        aam
1045
        xchg    al, ah
1046
        add     ax, '00'
1047
        mov     si, pros
1048
        mov     [si], ax
1049
        call    printplain
1050
        popa
1051
        jmp     .a1
1052
.nocd:
1053
; no - read only used sectors from floppy
1054
; now load floppy image to memory
1055
; at first load boot sector and first FAT table
1056
 
1057
; read only first sector and fill variables
1058
        mov     cx, 0x0001      ; first logical sector
1059
        xor     dx, dx          ; head = 0, drive = 0 (a:)
1060
        mov     al, 1           ; read one sector
1061
        mov     bx, 0xB000      ; es:bx -> data area
1062
        call    boot_read_floppy
1063
; fill the necessary parameters to work with a floppy
1064
        mov     ax, word [es:bx+24]
1065
        mov     word [BPB_SecPerTrk], ax
1066
        mov     ax, word [es:bx+26]
1067
        mov     word [BPB_NumHeads], ax
1068
        mov     ax, word [es:bx+17]
1069
        mov     word [BPB_RootEntCnt], ax
1070
        mov     ax, word [es:bx+14]
1071
        mov     word [BPB_RsvdSecCnt], ax
1072
        mov     ax, word [es:bx+19]
1073
        mov     word [BPB_TotSec16], ax
1074
        mov     al, byte [es:bx+13]
1075
        mov     byte [BPB_SecPerClus], al
1076
        mov     al, byte [es:bx+16]
1077
        mov     byte [BPB_NumFATs], al
1078
; 18.11.2008
1079
        mov     ax, word [es:bx+22]
1080
        mov     word [BPB_FATSz16], ax
1081
        mov     cx, word [es:bx+11]
1082
        mov     word [BPB_BytsPerSec], cx
1083
 
1084
; count of clusters in FAT12 ((size_of_FAT*2)/3)
1085
;        mov     ax, word [BPB_FATSz16]
1086
;        mov     cx, word [BPB_BytsPerSec]
1087
;end  18.11.2008
1088
        xor     dx, dx
1089
        mul     cx
1090
        shl     ax, 1
1091
        mov     cx, 3
1092
        div     cx              ; now ax - number of clusters in FAT12
1093
        mov     word [end_of_FAT], ax
1094
 
1095
; load first FAT table
1096
        mov     cx, 0x0002      ; startcyl,startsector          ; TODO!!!!!
1097
        xor     dx, dx          ; starthead,drive
1098
        mov     al, byte [BPB_FATSz16]     ; no of sectors to read
1099
        add     bx, word [BPB_BytsPerSec]  ; es:bx -> data area
1100
        call    boot_read_floppy
1101
        mov     bx, 0xB000
1102
 
1103
; and copy them to extended memory
1104
        mov     si, movedesc
1105
        mov     [si+8*2+3], bh          ; from
1106
 
1107
        mov     ax, word [BPB_BytsPerSec]
1108
        shr     ax, 1                   ; words per sector
1109
        mov     cx, word [BPB_RsvdSecCnt]
1110
        add     cx, word [BPB_FATSz16]
1111
        mul     cx
1112
        push    ax                      ; save to stack count of words in boot+FAT
1113
        xchg    ax, cx
1114
 
1115
        push    es
1116
        push    ds
1117
        pop     es
1118
        mov     ah, 0x87
1119
        int     0x15
1120
        pop     es
1121
        test    ah, ah
1122
        jz      @f
1123
sayerr_floppy:
1124
        mov     dx, 0x3f2
1125
        mov     al, 0
1126
        out     dx, al
1127
sayerr_memmove:
1128
        mov     si, memmovefailed
1129
        jmp     sayerr_plain
1130
@@:
1131
        pop     ax                      ; restore from stack count of words in boot+FAT
1132
        shl     ax, 1                   ; make bytes count from count of words
1133
        and     eax, 0ffffh
1134
        add     dword [si+8*3+2], eax
1135
 
1136
; copy first FAT to second copy
1137
; TODO: BPB_NumFATs !!!!!
1138
        add     bx, word [BPB_BytsPerSec]       ; !!! TODO: may be need multiply by BPB_RsvdSecCnt !!!
1139
        mov     byte [si+8*2+3], bh     ; bx - begin of FAT
1140
 
1141
        mov     ax, word [BPB_BytsPerSec]
1142
        shr     ax, 1                   ; words per sector
1143
        mov     cx, word [BPB_FATSz16]
1144
        mul     cx
1145
        mov     cx, ax                  ; cx - count of words in FAT
1146
 
1147
        push    es
1148
        push    ds
1149
        pop     es
1150
        mov     ah, 0x87
1151
        int     0x15
1152
        pop     es
1153
        test    ah, ah
1154
        jnz     sayerr_floppy
1155
 
1156
        mov     ax, cx
1157
        shl     ax, 1
1158
        and     eax, 0ffffh             ; ax - count of bytes in FAT
1159
        add     dword [si+8*3+2], eax
1160
 
1161
; reading RootDir
1162
; TODO: BPB_NumFATs
1163
        add     bx, ax
1164
        add     bx, 100h
1165
        and     bx, 0ff00h                      ; bx - place in buffer to write RootDir
1166
        push    bx
1167
 
1168
        mov     bx, word [BPB_BytsPerSec]
1169
        shr     bx, 5                           ; divide bx by 32
1170
        mov     ax, word [BPB_RootEntCnt]
1171
        xor     dx, dx
1172
        div     bx
1173
        push    ax                              ; ax - count of RootDir sectors
1174
 
1175
        mov     ax, word [BPB_FATSz16]
1176
        xor     cx, cx
1177
        mov     cl, byte [BPB_NumFATs]
1178
        mul     cx
1179
        add     ax, word [BPB_RsvdSecCnt]       ; ax - first sector of RootDir
1180
 
1181
        mov     word [FirstDataSector], ax
1182
        pop     bx
1183
        push    bx
1184
        add     word [FirstDataSector], bx      ; Begin of data region of floppy
1185
 
1186
; read RootDir
1187
        call    conv_abs_to_THS
1188
        pop     ax
1189
        pop     bx                              ; place in buffer to write
1190
        push    ax
1191
        call    boot_read_floppy                ; read RootDir into buffer
1192
; copy RootDir
1193
        mov     byte [si+8*2+3], bh             ; from buffer
1194
        pop     ax                              ; ax = count of RootDir sectors
1195
        mov     cx, word [BPB_BytsPerSec]
1196
        mul     cx
1197
        shr     ax, 1
1198
        mov     cx, ax                          ; count of words to copy
1199
        push    es
1200
        push    ds
1201
        pop     es
1202
        mov     ah, 0x87
1203
        int     0x15
1204
        pop     es
1205
 
1206
        mov     ax, cx
1207
        shl     ax, 1
1208
        and     eax, 0ffffh             ; ax - count of bytes in RootDir
1209
        add     dword [si+8*3+2], eax   ; add count of bytes copied
1210
 
1211
; Reading data clusters from floppy
1212
        mov     byte [si+8*2+3], bh
1213
        push    bx
1214
 
1215
        mov     di, 2                   ; First data cluster
1216
.read_loop:
1217
        mov     bx, di
1218
        shr     bx, 1                   ; bx+di = di*1.5
1219
        jnc     .even
1220
        test    word [es:bx+di+0xB200], 0xFFF0  ; TODO: may not be 0xB200 !!!
1221
        jmp     @f
1222
.even:
1223
        test    word [es:bx+di+0xB200], 0xFFF   ; TODO: may not be 0xB200 !!!
1224
 
1225
@@:
1226
        jz      .skip
1227
; read cluster di
1228
;.read:
1229
        ;conv cluster di to abs. sector ax
1230
        ; ax = (N-2) * BPB_SecPerClus + FirstDataSector
1231
        mov     ax, di
1232
        sub     ax, 2
1233
        xor     bx, bx
1234
        mov     bl, byte [BPB_SecPerClus]
1235
        mul     bx
1236
        add     ax, word [FirstDataSector]
1237
        call    conv_abs_to_THS
1238
        pop     bx
1239
        push    bx
1240
        mov     al, byte [BPB_SecPerClus]       ; number of sectors in cluster
1241
        call    boot_read_floppy
1242
        push    es
1243
        push    ds
1244
        pop     es
1245
        pusha
1246
;
1247
        mov     ax, word [BPB_BytsPerSec]
1248
        xor     cx, cx
1249
        mov     cl, byte [BPB_SecPerClus]
1250
        mul     cx
1251
        shr     ax, 1                           ; ax = (BPB_BytsPerSec * BPB_SecPerClus)/2
1252
        mov     cx, ax                          ; number of words to copy (count words in cluster)
1253
;
1254
        mov     ah, 0x87
1255
        int     0x15                            ; copy data
1256
        test    ah, ah
1257
        popa
1258
        pop     es
1259
        jnz     sayerr_floppy
1260
; skip cluster di
1261
.skip:
1262
        mov     ax, word [BPB_BytsPerSec]
1263
        xor     cx, cx
1264
        mov     cl, byte [BPB_SecPerClus]
1265
        mul     cx
1266
        and     eax, 0ffffh             ; ax - count of bytes in cluster
1267
        add     dword [si+8*3+2], eax
1268
 
1269
        mov     ax, word [end_of_FAT]   ; max cluster number
1270
        pusha
1271
; draw percentage
1272
; total clusters: ax
1273
; read clusters: di
1274
        xchg    ax, di
1275
        mov     cx, 100
1276
        mul     cx
1277
        div     di
1278
        aam
1279
        xchg    al, ah
1280
        add     ax, '00'
1281
        mov     si, pros
1282
        cmp     [si], ax
1283
        jz      @f
1284
        mov     [si], ax
1285
        call    printplain
1286
@@:
1287
        popa
1288
        inc     di
1289
        cmp     di, word [end_of_FAT]   ; max number of cluster
1290
        jnz     .read_loop
1291
        pop     bx                      ; clear stack
1292
 
1293
ok_sys_on_floppy:
1294
        mov     si, backspace2
1295
        call    printplain
1296
        mov     si, okt
1297
        call    printplain
1298
no_sys_on_floppy:
1299
        xor     ax, ax          ; reset drive
1300
        xor     dx, dx
1301
        int     0x13
1302
        mov     dx, 0x3f2       ; floppy motor off
1303
        mov     al, 0
1304
        out     dx, al
1305
 
1306
if defined extended_primary_loader
7129 dunkaist 1307
        cmp     [es:BOOT_DEV], 1
2288 clevermous 1308
        jne     no_sys_from_primary
1309
; load kolibri.img using callback from primary loader
1310
        and     word [movedesc + 24 + 2], 0
1311
        mov     byte [movedesc + 24 + 4], 10h
1312
; read in blocks of 64K until file is fully loaded
1313
        mov     ax, 1
1314
.repeat:
1315
        mov     di, image_file_struct
1316
        call    [bootcallback]
1317
        push    cs
1318
        pop     ds
1319
        push    cs
1320
        pop     es
1321
        cmp     bx, 1
1322
        ja      sayerr_badsect
1323
        push    bx
1324
        mov     si, movedesc
1325
        and     word [si + 16 + 2], 0
1326
        mov     byte [si + 16 + 4], 4
1327
        mov     ah, 87h
1328
        mov     cx, 8000h
1329
        int     15h
1330
        pop     bx
1331
        test    ah, ah
1332
        jnz     sayerr_memmove
1333
        inc     byte [si + 24 + 4]
1334
        test    bx, bx
1335
        jz      no_sys_from_primary
1336
        mov     ax, 2
1337
        jmp     .repeat
1338
no_sys_from_primary:
1339
end if
1340
 
1341
; SET GRAPHICS
1342
 
1343
        xor     ax, ax
1344
        mov     es, ax
1345
 
2466 Serge 1346
        mov     ax, [es:BOOT_VESA_MODE]         ; vga & 320x200
2288 clevermous 1347
        mov     bx, ax
1348
        cmp     ax, 0x13
1349
        je      setgr
1350
        cmp     ax, 0x12
1351
        je      setgr
1352
        mov     ax, 0x4f02              ; Vesa
1353
setgr:
1354
        int     0x10
1355
        test    ah, ah
1356
        mov     si, fatalsel
1357
        jnz     v_mode_error
1358
; set mode 0x12 graphics registers:
1359
        cmp     bx, 0x12
1360
        jne     gmok2
1361
 
1362
        mov     al, 0x05
1363
        mov     dx, 0x03ce
1364
        push    dx
1365
        out     dx, al      ; select GDC mode register
1366
        mov     al, 0x02
1367
        inc     dx
1368
        out     dx, al      ; set write mode 2
1369
 
1370
        mov     al, 0x02
1371
        mov     dx, 0x03c4
1372
        out     dx, al      ; select VGA sequencer map mask register
1373
        mov     al, 0x0f
1374
        inc     dx
1375
        out     dx, al      ; set mask for all planes 0-3
1376
 
1377
        mov     al, 0x08
1378
        pop     dx
1379
        out     dx, al      ; select GDC bit mask register
1380
                           ; for writes to 0x03cf
1381
gmok2:
1382
        push    ds
1383
        pop     es