source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int19h.asm@ 602

Last change on this file since 602 was 601, checked in by Krister Nordvall, 6 years ago

Changes:

  • Building the BIOS now works again.
  • Added a new IDE device type/transfer mode for use only with XT-IDE rev 2+ (or Chuck(G)-modded rev 1) cards installed in any of the following machines: Olivetti M24, AT&T PC6300, Xerox 6060 and Logabax Persona 1600. This new transfer mode is slightly faster than the regular XT-IDE rev 1 device type and requires that the card is configured for High Speed mode (or, in case of the card being a rev 1 card, has the Chuck(G) mod done). The new device type is called "XTIDE rev 2 (Olivetti M24)" in XTIDECFG.
  • Made some minor improvements to the library code that handles 'Drive Not Ready' errors in XTIDECFG.
  • Optimizations.
File size: 8.5 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Int 19h Handler (Boot Loader).
3
4;
5; XTIDE Universal BIOS and Associated Tools
6; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
7;
8; This program is free software; you can redistribute it and/or modify
9; it under the terms of the GNU General Public License as published by
10; the Free Software Foundation; either version 2 of the License, or
11; (at your option) any later version.
12;
13; This program is distributed in the hope that it will be useful,
14; but WITHOUT ANY WARRANTY; without even the implied warranty of
15; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16; GNU General Public License for more details.
17; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
18;
19
20; Section containing code
21SECTION .text
22
23;--------------------------------------------------------------------
24; Int19h_BootLoaderHandler
25; Parameters:
26; Nothing
27; Returns:
28; Never returns (loads operating system)
29;--------------------------------------------------------------------
30Int19h_BootLoaderHandler:
31 sti ; Enable interrupts
32%ifdef CLD_NEEDED
33 cld ; String instructions to increment pointers
34%endif
35%ifdef MODULE_VERY_LATE_INIT
36 LOAD_BDA_SEGMENT_TO ds, ax ; Load BDA segment (zero) to DS
37 les ax, [TEMPORARY_VECTOR_FOR_SYSTEM_INT13h*4]
38 mov [BIOS_DISK_INTERRUPT_13h*4], ax
39 mov [BIOS_DISK_INTERRUPT_13h*4+2], es
40 push ds ; BDA segment (zero)...
41 pop es ; ...to ES
42%else
43 LOAD_BDA_SEGMENT_TO es, ax ; Load BDA segment (zero) to ES
44%endif
45 ; Fall to .PrepareBootLoaderStack
46
47
48;--------------------------------------------------------------------
49; Drive detection and boot menu use lots of stack so it is
50; wise to relocate stack. Otherwise something important from
51; interrupt vectors are likely corrupted, likely our own DPTs if
52; they are located to 30:0h.
53;
54; .PrepareBootLoaderStack
55; Parameters:
56; ES: BDA and interrupt vector segment (zero)
57; Returns:
58; Never returns (loads operating system)
59;--------------------------------------------------------------------
60.PrepareBootLoaderStack:
61 STORE_POST_STACK_POINTER
62 SWITCH_TO_BOOT_MENU_STACK
63 ; Fall to .InitializeDisplay
64
65
66;--------------------------------------------------------------------
67; .InitializeDisplay
68; Parameters:
69; ES: BDA and interrupt vector segment (zero)
70; Returns:
71; Never returns (loads operating system)
72;--------------------------------------------------------------------
73.InitializeDisplay:
74 ; Change display mode if necessary
75 mov ax, [cs:ROMVARS.wDisplayMode] ; AH 00h = Set Video Mode
76 cmp al, DEFAULT_TEXT_MODE
77 je SHORT .InitializeDisplayLibrary
78 int BIOS_VIDEO_INTERRUPT_10h
79.InitializeDisplayLibrary:
80 call DetectPrint_InitializeDisplayContext
81 ; Fall to .InitializeBiosAndDetectDrives
82
83
84;--------------------------------------------------------------------
85; .InitializeBiosAndDetectDrives
86; Parameters:
87; ES: BDA and interrupt vector segment (zero)
88; Returns:
89; DS: RAMVARS segment
90;--------------------------------------------------------------------
91.InitializeBiosAndDetectDrives:
92 call Initialize_AndDetectDrives
93
94%ifdef MODULE_HOTKEYS
95 ; Last hard drive might have scrolled Hotkey Bar out of screen.
96 ; We want to display it during wait.
97 ;call HotkeyBar_UpdateDuringDriveDetection
98
99.WaitUntilTimeToCloseHotkeyBar:
100 call TimerTicks_ReadFromBdaToAX
101 sub ax, [es:BOOTVARS.hotkeyVars+HOTKEYVARS.wTimeWhenDisplayed]
102 cmp ax, MIN_TIME_TO_DISPLAY_HOTKEY_BAR
103 jb SHORT .WaitUntilTimeToCloseHotkeyBar
104
105 ; Restore system timer tick handler since hotkeys are no longer needed
106 cli
107 mov ax, [es:BOOTVARS.hotkeyVars+HOTKEYVARS.fpPrevTimerHandler]
108 mov [es:BIOS_SYSTEM_TIMER_TICK_INTERRUPT_1Ch*4], ax
109 mov ax, [es:BOOTVARS.hotkeyVars+HOTKEYVARS.fpPrevTimerHandler+2]
110 mov [es:BIOS_SYSTEM_TIMER_TICK_INTERRUPT_1Ch*4+2], ax
111 sti
112%endif
113 ; Fall to .ResetAllDrives
114
115
116;--------------------------------------------------------------------
117; .ResetAllDrives
118; Parameters:
119; DS: RAMVARS segment
120; ES: BDA and interrupt vector segment (zero)
121; Returns:
122; Nothing
123;--------------------------------------------------------------------
124.ResetAllDrives:
125 ; Reset all drives in the system, not just our drives.
126 xor ax, ax ; Disk Controller Reset
127 mov dl, 80h ; Reset all hard drives and floppy drives
128 int BIOS_DISK_INTERRUPT_13h
129 ; Fall to SelectDriveToBootFrom
130
131
132;--------------------------------------------------------------------
133; SelectDriveToBootFrom
134; Parameters:
135; DS: RAMVARS segment
136; ES: BDA and interrupt vector segment (zero)
137; Returns:
138; Never returns (loads operating system)
139;--------------------------------------------------------------------
140; The following macro could be easily inlined below. Why a macro? Depending on the combination
141; of MODULE_HOTKEYS or MODULE_BOOT_MENU, this code needs to either come before or after the
142; call to the boot menu.
143;
144%macro TRY_TO_BOOT_DL_AND_DH_DRIVES 0
145 push dx ; it's OK if this is left on the stack, if we are
146 ; successful, the following call does not return
147 call BootSector_TryToLoadFromDriveDL_AndBoot
148 pop dx
149 mov dl, dh
150 call BootSector_TryToLoadFromDriveDL_AndBoot
151%endmacro
152
153
154SelectDriveToBootFrom: ; Function starts here
155%ifdef MODULE_HOTKEYS
156 mov al, [es:BOOTVARS.hotkeyVars+HOTKEYVARS.bScancode]
157 cmp al, ROM_BOOT_HOTKEY_SCANCODE
158 je SHORT .RomBoot ; CF clear so ROM boot
159%ifdef MODULE_BOOT_MENU
160 cmp al, BOOT_MENU_HOTKEY_SCANCODE
161 je SHORT .BootMenu
162%endif ; MODULE_BOOT_MENU
163
164.TryUsingHotKeysCode:
165 call HotkeyBar_GetBootDriveNumbersToDX
166 call DriveXlate_SetDriveToSwap ; Enable primary boot device translation
167 xchg dl, dh
168 call DriveXlate_SetDriveToSwap ; Enable secondary boot device translation
169 xchg dl, dh
170 call DriveXlate_ToOrBack ; Translate now so boot device will appear as 00h or 80h to OS
171 TRY_TO_BOOT_DL_AND_DH_DRIVES
172 ;; falls through to boot menu, if it is present. If not present, falls through to rom boot.
173%endif ; MODULE_HOTKEYS
174
175
176%ifdef MODULE_BOOT_MENU
177.BootMenu:
178 call BootMenu_DisplayAndReturnDriveInDLRomBootClearCF
179 jnc SHORT .RomBoot ; CF clear so ROM boot
180
181 call DriveXlate_Reset
182%ifdef MODULE_HOTKEYS
183 jmp SHORT .TryUsingHotKeysCode ; Selected drive stored as hotkey
184%else ; Boot menu without hotkeys, secondary boot drive is always 00h or 80h
185 mov dh, dl ; Setup for secondary drive
186 not dh ; Floppy goes to HD, or vice versa
187 and dh, 80h ; Go to first drive of the floppy or HD set
188 call DriveXlate_SetDriveToSwap
189 call DriveXlate_ToOrBack
190 TRY_TO_BOOT_DL_AND_DH_DRIVES
191 jmp SHORT .BootMenu ; Show boot menu again
192%endif ; MODULE_HOTKEYS
193
194%endif ; MODULE_BOOT_MENU
195
196; No hotkeys and no boot menu means fixed "A then C" boot order
197%ifndef MODULE_HOTKEYS OR MODULE_BOOT_MENU
198 xor dl, dl ; Try to boot from Floppy Drive A
199 call BootSector_TryToLoadFromDriveDL_AndBoot
200 mov dl, 80h ; Try to boot from Hard Drive C
201 call BootSector_TryToLoadFromDriveDL_AndBoot
202%endif
203
204.RomBoot:
205%ifdef MODULE_DRIVEXLATE
206 call DriveXlate_Reset ; Clean up any drive mappings before Rom Boot
207%endif
208 stc
209 ;; fall through to Int19h_JumpToBootSectorInESBXOrRomBoot
210
211;--------------------------------------------------------------------
212; Int19h_JumpToBootSectorInESBXOrRomBoot
213;
214; Switches back to the POST stack, clears the DS and ES registers,
215; and either jumps to the MBR (Master Boot Record) that was just read,
216; or calls the ROM's boot routine on interrupt 18h.
217;
218; Parameters:
219; DL: Drive to boot from (translated, 00h or 80h)
220; CF: Clear for Boot Sector Boot
221; Set for ROM Boot
222; ES:BX: (if CF clear) Ptr to boot sector (ES = zero)
223;
224; Returns:
225; Never returns
226;--------------------------------------------------------------------
227Int19h_JumpToBootSectorInESBXOrRomBoot:
228 mov ax, es ; Clear AX. NOTE: can't use XOR (LOAD_BDA_SEGMENT_TO) as it impacts CF
229 SWITCH_BACK_TO_POST_STACK
230
231; clear segment registers before boot sector or rom call
232Int19h_JumpToBootSectorInESBXOrRomBootWithoutStackChange:
233 mov ax, es ; Clear AX and preserve CF
234 mov ds, ax
235%ifdef USE_386
236 mov fs, ax
237 mov gs, ax
238%endif
239 jc SHORT .RomBoot
240
241; jump to boot sector
242 push es ; sgment address for MBR
243 push bx ; offset address for MBR
244 retf ; NOTE: DL is set to the drive number
245
246; Boot by calling INT 18h (ROM Basic of ROM DOS)
247.RomBoot:
248 int BIOS_BOOT_FAILURE_INTERRUPT_18h ; Never returns
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