source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/Interrupts.asm@ 394

Last change on this file since 394 was 392, checked in by aitotat@…, 13 years ago

Changes to XTIDE Universal BIOS:

  • Greatly improved Hotkey Bar is displayed during drive detection.
  • 8k builds no longer include boot menu.
  • Boot menu is displayed only if F2 is pressed during drive detection.
  • Some changes to directory structure.


File size: 7.7 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Functions for initializing the BIOS.
3
4;
5; XTIDE Universal BIOS and Associated Tools
6; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 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; Interrupts_InitializeInterruptVectors
25; Parameters:
26; DS: RAMVARS segment
27; ES: BDA and Interrupt Vector segment (zero)
28; Returns:
29; Nothing
30; Corrupts registers:
31; All except segments
32;--------------------------------------------------------------------
33Interrupts_InitializeInterruptVectors:
34 ; Fall to .InitializeInt13hAnd40h
35
36;--------------------------------------------------------------------
37; .InitializeInt13hAnd40h
38; Parameters:
39; DS: RAMVARS segment
40; ES: BDA and Interrupt Vector segment (zero)
41; Returns:
42; Nothing
43; Corrupts registers:
44; AX, BX, CX, DX, SI, DI
45;--------------------------------------------------------------------
46.InitializeInt13hAnd40h:
47 mov ax, [es:BIOS_DISK_INTERRUPT_13h*4+2]; Load old INT 13h segment
48 mov [RAMVARS.fpOldI13h+2], ax ; Store old INT 13h segment
49 xchg dx, ax
50 mov ax, [es:BIOS_DISK_INTERRUPT_13h*4] ; Load old INT 13h offset
51 mov [RAMVARS.fpOldI13h], ax ; Store old INT 13h offset
52
53 ; Only store INT 13h handler to 40h if 40h is not already installed.
54 ; At least AMI BIOS for 286 stores 40h handler by itself and calls
55 ; 40h from 13h. That system locks to infinite loop if we copy 13h to 40h.
56 call FloppyDrive_IsInt40hInstalled
57 jc SHORT .Int40hAlreadyInstalled
58 mov [es:BIOS_DISKETTE_INTERRUPT_40h*4], ax ; Store old INT 13h offset
59 mov [es:BIOS_DISKETTE_INTERRUPT_40h*4+2], dx ; Store old INT 13h segment
60.Int40hAlreadyInstalled:
61
62 mov al, BIOS_DISK_INTERRUPT_13h ; INT 13h interrupt vector offset
63 mov si, Int13h_DiskFunctionsHandler ; Interrupt handler offset
64 call Interrupts_InstallHandlerToVectorInALFromCSSI
65
66 ; Install INT 19h handler to properly reset the system
67 mov al, BIOS_BOOT_LOADER_INTERRUPT_19h ; INT 19h interrupt vector offset
68 mov si, Int19hReset_Handler ; INT 19h handler to reboot the system
69 call Interrupts_InstallHandlerToVectorInALFromCSSI
70 ; Fall to .InitializeHardwareIrqHandlers
71
72;--------------------------------------------------------------------
73; .InitializeHardwareIrqHandlers
74; Parameters:
75; ES: BDA and Interrupt Vector segment (zero)
76; Returns:
77; Nothing
78; Corrupts registers:
79; BX, CX, DX, SI, DI, AX
80;--------------------------------------------------------------------
81.InitializeHardwareIrqHandlers:
82 call RamVars_GetIdeControllerCountToCX
83 mov di, ROMVARS.ideVars0 ; CS:SI points to first IDEVARS
84.IdeControllerLoop:
85 mov al, [cs:di+IDEVARS.bIRQ]
86 add di, BYTE IDEVARS_size ; Increment to next controller
87 call .InstallLowOrHighIrqHandler
88 loop .IdeControllerLoop
89.Return:
90 ret ; This ret is shared with .InstallLowOrHighIrqHandler
91
92;--------------------------------------------------------------------
93; .InstallLowOrHighIrqHandler
94; Parameters:
95; AL: IRQ number, 0 if IRQ disabled
96; ES: BDA and Interrupt Vector segment (zero)
97; Returns:
98; Nothing
99; Corrupts registers:
100; BX, SI
101;--------------------------------------------------------------------
102.InstallLowOrHighIrqHandler:
103 test al, al
104 jz SHORT .Return ; IRQ not used
105 cmp al, 8
106 jb SHORT .InstallLowIrqHandler
107 ; Fall to .InstallHighIrqHandler
108
109;--------------------------------------------------------------------
110; .InstallHighIrqHandler
111; Parameters:
112; BX: IRQ number (8...15)
113; ES: BDA and Interrupt Vector segment (zero)
114; Returns:
115; Nothing
116; Corrupts registers:
117; AL, BX, SI
118;--------------------------------------------------------------------
119.InstallHighIrqHandler:
120 add al, BYTE HARDWARE_IRQ_8_INTERRUPT_70h - 8 ; Interrupt vector number
121 mov si, IdeIrq_InterruptServiceRoutineForIrqs8to15
122 jmp SHORT Interrupts_InstallHandlerToVectorInALFromCSSI
123
124;--------------------------------------------------------------------
125; .InstallLowIrqHandler
126; Parameters:
127; AL: IRQ number (0...7)
128; ES: BDA and Interrupt Vector segment (zero)
129; Returns:
130; Nothing
131; Corrupts registers:
132; AL, BX, SI
133;--------------------------------------------------------------------
134.InstallLowIrqHandler:
135 add al, BYTE HARDWARE_IRQ_0_INTERRUPT_08h ; Interrupt vector number
136 mov si, IdeIrq_InterruptServiceRoutineForIrqs2to7
137 ; Fall to Interrupts_InstallHandlerToVectorInALFromCSSI
138
139
140;--------------------------------------------------------------------
141; Interrupts_InstallHandlerToVectorInALFromCSSI
142; Parameters:
143; AL: Interrupt vector number (for example 13h)
144; ES: BDA and Interrupt Vector segment (zero)
145; CS:SI: Ptr to interrupt handler
146; Returns:
147; Nothing
148; Corrupts registers:
149; AX, BX
150;--------------------------------------------------------------------
151Interrupts_InstallHandlerToVectorInALFromCSSI:
152 mov bl, 4 ; Shift for DWORD offset, MUL smaller than other alternatives
153 mul bl
154 xchg ax, bx
155 mov [es:bx], si ; Store offset
156 mov [es:bx+2], cs ; Store segment
157 ret
158
159
160;--------------------------------------------------------------------
161; Interrupts_UnmaskInterruptControllerForDriveInDSDI
162; Parameters:
163; DS:DI: Ptr to DPT
164; Returns:
165; Nothing
166; Corrupts registers:
167; AX, BX, DX
168;--------------------------------------------------------------------
169Interrupts_UnmaskInterruptControllerForDriveInDSDI:
170 eMOVZX bx, [di+DPT.bIdevarsOffset]
171 mov al, [cs:bx+IDEVARS.bIRQ]
172 test al, al
173 jz SHORT .Return ; Interrupts disabled
174 cmp al, 8
175 jb SHORT .UnmaskLowIrqController
176 ; Fall to .UnmaskHighIrqController
177
178;--------------------------------------------------------------------
179; .UnmaskHighIrqController
180; Parameters:
181; AL: IRQ number (8...15)
182; Returns:
183; Nothing
184; Corrupts registers:
185; AX, DX
186;--------------------------------------------------------------------
187.UnmaskHighIrqController:
188 sub al, 8 ; Slave interrupt number
189 mov dx, SLAVE_8259_IMR
190 call .ClearBitFrom8259MaskRegister
191 mov al, 2 ; Master IRQ 2 to allow slave IRQs
192 ; Fall to .UnmaskLowIrqController
193
194;--------------------------------------------------------------------
195; .UnmaskLowIrqController
196; Parameters:
197; AL: IRQ number (0...7)
198; Returns:
199; Nothing
200; Corrupts registers:
201; AX, DX
202;--------------------------------------------------------------------
203.UnmaskLowIrqController:
204 mov dx, MASTER_8259_IMR
205 ; Fall to .ClearBitFrom8259MaskRegister
206
207;--------------------------------------------------------------------
208; .ClearBitFrom8259MaskRegister
209; Parameters:
210; AL: 8259 interrupt index (0...7)
211; DX: Port address to Interrupt Mask Register
212; Returns:
213; Nothing
214; Corrupts registers:
215; AX
216;--------------------------------------------------------------------
217.ClearBitFrom8259MaskRegister:
218 push cx
219 xchg ax, cx ; IRQ index to CL
220 mov ch, 1 ; Load 1 to be shifted
221 shl ch, cl ; Shift bit to correct position
222 not ch ; Invert to create bit mask for clearing
223 in al, dx ; Read Interrupt Mask Register
224 and al, ch ; Clear wanted bit
225 out dx, al ; Write modified Interrupt Mask Register
226 pop cx
227.Return:
228 ret
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