source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/Interrupts.asm@ 500

Last change on this file since 500 was 492, checked in by gregli@…, 12 years ago

Removed the dependency between MODULE_BOOT_MENU and MODULE_HOTKEYS. With these changes, 0, 1, or 2 of them can be included in a build. This change also means that the hotkeys don't work while the menu is up. But the most important hotkey there was for Rom Boot, and that has been added to the menu as a choice proper. Lots of changes across the board in the hotkeys code - even if we eventually back this change out (becaue, for example we want hotkeys to work in the menu) we should probably start from this base and add that functionality back in, as these changes results in approximately 120 bytes of savings and includes new functionality, such as the Rom Boot menu item and the Com Detect hotkey.

File size: 8.3 KB
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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; Drives must be detected before this function is called!
25;
26; Interrupts_InitializeInterruptVectors
27; Parameters:
28; DS: RAMVARS segment
29; ES: BDA and Interrupt Vector segment (zero)
30; Returns:
31; Nothing
32; Corrupts registers:
33; All except segments
34;--------------------------------------------------------------------
35Interrupts_InitializeInterruptVectors:
36 ; Install INT 19h handler to properly reset the system
37 mov al, BIOS_BOOT_LOADER_INTERRUPT_19h ; INT 19h interrupt vector offset
38 mov si, Int19hReset_Handler ; INT 19h handler to reboot the system
39 call Interrupts_InstallHandlerToVectorInALFromCSSI
40
41 ; If no drives detected, leave system INT 13h and 40h handlers
42 ; in place. We need our INT 13h handler to swap drive letters.
43%ifndef MODULE_DRIVEXLATE
44 cmp BYTE [RAMVARS.bDrvCnt], 0
45 je SHORT Interrupts_InstallHandlerToVectorInALFromCSSI.Interrupts_Return
46%endif
47 ; Fall to .InitializeInt13hAnd40h
48
49;--------------------------------------------------------------------
50; .InitializeInt13hAnd40h
51; Parameters:
52; DS: RAMVARS segment
53; ES: BDA and Interrupt Vector segment (zero)
54; Returns:
55; Nothing
56; Corrupts registers:
57; AX, BX, CX, DX, SI, DI
58;--------------------------------------------------------------------
59.InitializeInt13hAnd40h:
60 mov ax, [es:BIOS_DISK_INTERRUPT_13h*4+2]; Load old INT 13h segment
61 mov [RAMVARS.fpOldI13h+2], ax ; Store old INT 13h segment
62 xchg dx, ax
63 mov ax, [es:BIOS_DISK_INTERRUPT_13h*4] ; Load old INT 13h offset
64 mov [RAMVARS.fpOldI13h], ax ; Store old INT 13h offset
65
66 ; Only store INT 13h handler to 40h if 40h is not already installed.
67 ; At least AMI BIOS for 286 stores 40h handler by itself and calls
68 ; 40h from 13h. That system locks to infinite loop if we copy 13h to 40h.
69 call FloppyDrive_IsInt40hInstalled
70 jc SHORT .Int40hAlreadyInstalled
71 mov [es:BIOS_DISKETTE_INTERRUPT_40h*4], ax ; Store old INT 13h offset
72 mov [es:BIOS_DISKETTE_INTERRUPT_40h*4+2], dx ; Store old INT 13h segment
73.Int40hAlreadyInstalled:
74
75 mov al, BIOS_DISK_INTERRUPT_13h ; INT 13h interrupt vector offset
76 mov si, Int13h_DiskFunctionsHandler
77%ifdef RELOCATE_INT13H_STACK
78 test BYTE [cs:ROMVARS.wFlags], FLG_ROMVARS_FULLMODE
79 eCMOVNZ si, Int13h_DiskFunctionsHandlerWithStackChange
80%endif
81
82%ifndef MODULE_IRQ
83 ; Fall to Interrupts_InstallHandlerToVectorInALFromCSSI
84%else
85 call Interrupts_InstallHandlerToVectorInALFromCSSI
86 ; Fall to .InitializeHardwareIrqHandlers
87
88;--------------------------------------------------------------------
89; .InitializeHardwareIrqHandlers
90; Parameters:
91; ES: BDA and Interrupt Vector segment (zero)
92; Returns:
93; Nothing
94; Corrupts registers:
95; BX, CX, DX, SI, DI, AX
96;--------------------------------------------------------------------
97.InitializeHardwareIrqHandlers:
98 call RamVars_GetIdeControllerCountToCX
99 mov di, ROMVARS.ideVars0+IDEVARS.bIRQ ; CS:SI points to first IDEVARS
100.IdeControllerLoop:
101 mov al, [cs:di]
102 add di, BYTE IDEVARS_size ; Increment to next controller
103 call .InstallLowOrHighIrqHandler
104 loop .IdeControllerLoop
105.Return:
106 ret ; This ret is shared with .InstallLowOrHighIrqHandler
107
108;--------------------------------------------------------------------
109; .InstallLowOrHighIrqHandler
110; Parameters:
111; AL: IRQ number, 0 if IRQ disabled
112; ES: BDA and Interrupt Vector segment (zero)
113; Returns:
114; Nothing
115; Corrupts registers:
116; BX, SI
117;--------------------------------------------------------------------
118.InstallLowOrHighIrqHandler:
119 test al, al
120 jz SHORT .Return ; IRQ not used
121 cmp al, 8
122 jb SHORT .InstallLowIrqHandler
123 ; Fall to .InstallHighIrqHandler
124
125;--------------------------------------------------------------------
126; .InstallHighIrqHandler
127; Parameters:
128; BX: IRQ number (8...15)
129; ES: BDA and Interrupt Vector segment (zero)
130; Returns:
131; Nothing
132; Corrupts registers:
133; AL, BX, SI
134;--------------------------------------------------------------------
135.InstallHighIrqHandler:
136 add al, BYTE HARDWARE_IRQ_8_INTERRUPT_70h - 8 ; Interrupt vector number
137 mov si, IdeIrq_InterruptServiceRoutineForIrqs8to15
138 jmp SHORT Interrupts_InstallHandlerToVectorInALFromCSSI
139
140;--------------------------------------------------------------------
141; .InstallLowIrqHandler
142; Parameters:
143; AL: IRQ number (0...7)
144; ES: BDA and Interrupt Vector segment (zero)
145; Returns:
146; Nothing
147; Corrupts registers:
148; AL, BX, SI
149;--------------------------------------------------------------------
150.InstallLowIrqHandler:
151 add al, BYTE HARDWARE_IRQ_0_INTERRUPT_08h ; Interrupt vector number
152 mov si, IdeIrq_InterruptServiceRoutineForIrqs2to7
153 ; Fall to Interrupts_InstallHandlerToVectorInALFromCSSI
154%endif ; MODULE_IRQ
155
156
157;--------------------------------------------------------------------
158; Interrupts_InstallHandlerToVectorInALFromCSSI
159; Parameters:
160; AL: Interrupt vector number (for example 13h)
161; ES: BDA and Interrupt Vector segment (zero)
162; CS:SI: Ptr to interrupt handler
163; Returns:
164; Nothing
165; Corrupts registers:
166; AX, BX
167;--------------------------------------------------------------------
168Interrupts_InstallHandlerToVectorInALFromCSSI:
169 mov bl, 4 ; Shift for DWORD offset, MUL smaller than other alternatives
170 mul bl
171 xchg ax, bx
172 mov [es:bx], si ; Store offset
173 mov [es:bx+2], cs ; Store segment
174.Interrupts_Return:
175 ret
176
177
178%ifdef MODULE_IRQ
179;--------------------------------------------------------------------
180; Interrupts_UnmaskInterruptControllerForDriveInDSDI
181; Parameters:
182; DS:DI: Ptr to DPT
183; Returns:
184; Nothing
185; Corrupts registers:
186; AX, BX, DX
187;--------------------------------------------------------------------
188Interrupts_UnmaskInterruptControllerForDriveInDSDI:
189 eMOVZX bx, [di+DPT.bIdevarsOffset]
190 mov al, [cs:bx+IDEVARS.bIRQ]
191 test al, al
192 jz SHORT .Return ; Interrupts disabled
193 cmp al, 8
194 jb SHORT .UnmaskLowIrqController
195 ; Fall to .UnmaskHighIrqController
196
197;--------------------------------------------------------------------
198; .UnmaskHighIrqController
199; Parameters:
200; AL: IRQ number (8...15)
201; Returns:
202; Nothing
203; Corrupts registers:
204; AX, DX
205;--------------------------------------------------------------------
206.UnmaskHighIrqController:
207 sub al, 8 ; Slave interrupt number
208 mov dx, SLAVE_8259_IMR
209 call .ClearBitFrom8259MaskRegister
210 mov al, 2 ; Master IRQ 2 to allow slave IRQs
211 ; Fall to .UnmaskLowIrqController
212
213;--------------------------------------------------------------------
214; .UnmaskLowIrqController
215; Parameters:
216; AL: IRQ number (0...7)
217; Returns:
218; Nothing
219; Corrupts registers:
220; AX, DX
221;--------------------------------------------------------------------
222.UnmaskLowIrqController:
223 mov dx, MASTER_8259_IMR
224 ; Fall to .ClearBitFrom8259MaskRegister
225
226;--------------------------------------------------------------------
227; .ClearBitFrom8259MaskRegister
228; Parameters:
229; AL: 8259 interrupt index (0...7)
230; DX: Port address to Interrupt Mask Register
231; Returns:
232; Nothing
233; Corrupts registers:
234; AX
235;--------------------------------------------------------------------
236.ClearBitFrom8259MaskRegister:
237 push cx
238 xchg ax, cx ; IRQ index to CL
239 mov ch, 1 ; Load 1 to be shifted
240 shl ch, cl ; Shift bit to correct position
241 not ch ; Invert to create bit mask for clearing
242 in al, dx ; Read Interrupt Mask Register
243 and al, ch ; Clear wanted bit
244 out dx, al ; Write modified Interrupt Mask Register
245 pop cx
246.Return:
247 ret
248
249%endif ; MODULE_IRQ
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