source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/Interrupts.asm@ 377

Last change on this file since 377 was 376, checked in by gregli@…, 13 years ago

WIDE checkin... Added copyright and license information to sorce files, as per the GPL instructions for usage.
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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 ; Fall to .InitializeHardwareIrqHandlers
66
67;--------------------------------------------------------------------
68; .InitializeHardwareIrqHandlers
69; Parameters:
70; ES: BDA and Interrupt Vector segment (zero)
71; Returns:
72; Nothing
73; Corrupts registers:
74; BX, CX, DX, SI, DI, AX
75;--------------------------------------------------------------------
76.InitializeHardwareIrqHandlers:
77 call RamVars_GetIdeControllerCountToCX
78 mov di, ROMVARS.ideVars0 ; CS:SI points to first IDEVARS
79.IdeControllerLoop:
80 mov al, [cs:di+IDEVARS.bIRQ]
81 add di, BYTE IDEVARS_size ; Increment to next controller
82 call .InstallLowOrHighIrqHandler
83 loop .IdeControllerLoop
84.Return:
85 ret ; This ret is shared with .InstallLowOrHighIrqHandler
86
87;--------------------------------------------------------------------
88; .InstallLowOrHighIrqHandler
89; Parameters:
90; AL: IRQ number, 0 if IRQ disabled
91; ES: BDA and Interrupt Vector segment (zero)
92; Returns:
93; Nothing
94; Corrupts registers:
95; BX, SI
96;--------------------------------------------------------------------
97.InstallLowOrHighIrqHandler:
98 test al, al
99 jz SHORT .Return ; IRQ not used
100 cmp al, 8
101 jb SHORT .InstallLowIrqHandler
102 ; Fall to .InstallHighIrqHandler
103
104;--------------------------------------------------------------------
105; .InstallHighIrqHandler
106; Parameters:
107; BX: IRQ number (8...15)
108; ES: BDA and Interrupt Vector segment (zero)
109; Returns:
110; Nothing
111; Corrupts registers:
112; AL, BX, SI
113;--------------------------------------------------------------------
114.InstallHighIrqHandler:
115 add al, BYTE HARDWARE_IRQ_8_INTERRUPT_70h - 8 ; Interrupt vector number
116 mov si, IdeIrq_InterruptServiceRoutineForIrqs8to15
117 jmp SHORT Interrupts_InstallHandlerToVectorInALFromCSSI
118
119;--------------------------------------------------------------------
120; .InstallLowIrqHandler
121; Parameters:
122; AL: IRQ number (0...7)
123; ES: BDA and Interrupt Vector segment (zero)
124; Returns:
125; Nothing
126; Corrupts registers:
127; AL, BX, SI
128;--------------------------------------------------------------------
129.InstallLowIrqHandler:
130 add al, BYTE HARDWARE_IRQ_0_INTERRUPT_08h ; Interrupt vector number
131 mov si, IdeIrq_InterruptServiceRoutineForIrqs2to7
132 ; Fall to Interrupts_InstallHandlerToVectorInALFromCSSI
133
134
135;--------------------------------------------------------------------
136; Interrupts_InstallHandlerToVectorInALFromCSSI
137; Parameters:
138; AL: Interrupt vector number (for example 13h)
139; ES: BDA and Interrupt Vector segment (zero)
140; CS:SI: Ptr to interrupt handler
141; Returns:
142; Nothing
143; Corrupts registers:
144; AX, BX
145;--------------------------------------------------------------------
146Interrupts_InstallHandlerToVectorInALFromCSSI:
147 mov bl, 4 ; Shift for DWORD offset, MUL smaller than other alternatives
148 mul bl
149 xchg ax, bx
150 mov [es:bx], si ; Store offset
151 mov [es:bx+2], cs ; Store segment
152 ret
153
154
155;--------------------------------------------------------------------
156; Interrupts_UnmaskInterruptControllerForDriveInDSDI
157; Parameters:
158; DS:DI: Ptr to DPT
159; Returns:
160; Nothing
161; Corrupts registers:
162; AX, BX, DX
163;--------------------------------------------------------------------
164Interrupts_UnmaskInterruptControllerForDriveInDSDI:
165 eMOVZX bx, [di+DPT.bIdevarsOffset]
166 mov al, [cs:bx+IDEVARS.bIRQ]
167 test al, al
168 jz SHORT .Return ; Interrupts disabled
169 cmp al, 8
170 jb SHORT .UnmaskLowIrqController
171 ; Fall to .UnmaskHighIrqController
172
173;--------------------------------------------------------------------
174; .UnmaskHighIrqController
175; Parameters:
176; AL: IRQ number (8...15)
177; Returns:
178; Nothing
179; Corrupts registers:
180; AX, DX
181;--------------------------------------------------------------------
182.UnmaskHighIrqController:
183 sub al, 8 ; Slave interrupt number
184 mov dx, SLAVE_8259_IMR
185 call .ClearBitFrom8259MaskRegister
186 mov al, 2 ; Master IRQ 2 to allow slave IRQs
187 ; Fall to .UnmaskLowIrqController
188
189;--------------------------------------------------------------------
190; .UnmaskLowIrqController
191; Parameters:
192; AL: IRQ number (0...7)
193; Returns:
194; Nothing
195; Corrupts registers:
196; AX, DX
197;--------------------------------------------------------------------
198.UnmaskLowIrqController:
199 mov dx, MASTER_8259_IMR
200 ; Fall to .ClearBitFrom8259MaskRegister
201
202;--------------------------------------------------------------------
203; .ClearBitFrom8259MaskRegister
204; Parameters:
205; AL: 8259 interrupt index (0...7)
206; DX: Port address to Interrupt Mask Register
207; Returns:
208; Nothing
209; Corrupts registers:
210; AX
211;--------------------------------------------------------------------
212.ClearBitFrom8259MaskRegister:
213 push cx
214 xchg ax, cx ; IRQ index to CL
215 mov ch, 1 ; Load 1 to be shifted
216 shl ch, cl ; Shift bit to correct position
217 not ch ; Invert to create bit mask for clearing
218 in al, dx ; Read Interrupt Mask Register
219 and al, ch ; Clear wanted bit
220 out dx, al ; Write modified Interrupt Mask Register
221 pop cx
222.Return:
223 ret
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