source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/Initialize.asm@ 155

Last change on this file since 155 was 152, checked in by Tomi Tilli, 14 years ago

Changes to XTIDE Universal BIOS:

  • XTIDE mod should now be supported (untested).
  • Interrupt Service Routine no longer requires variable from RAMVARS.
  • Some small improvements.
File size: 3.2 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Functions for initializing the BIOS.
3
4; Section containing code
5SECTION .text
6
7;--------------------------------------------------------------------
8; Initializes the BIOS.
9; This function is called from main BIOS ROM search routine.
10;
11; Initialize_FromMainBiosRomSearch
12; Parameters:
13; Nothing
14; Returns:
15; Nothing
16; Corrupts registers:
17; Nothing
18;--------------------------------------------------------------------
19Initialize_FromMainBiosRomSearch:
20 pushf
21 push es
22 push ds
23 ePUSHA
24
25 LOAD_BDA_SEGMENT_TO es, ax
26 call Initialize_ShouldSkip
27 jnz SHORT .SkipRomInitialization
28
29%ifdef USE_AT ; Early initialization on AT build
30 call Initialize_AndDetectDrives
31%else ; Late initialization on XT builds
32 call Int19hLate_InitializeInt19h
33%endif
34.SkipRomInitialization:
35 ePOPA
36 pop ds
37 pop es
38 popf
39 retf
40
41
42;--------------------------------------------------------------------
43; Checks if user wants to skip ROM initialization.
44;
45; Initialize_ShouldSkip
46; Parameters:
47; ES: BDA segment
48; Returns:
49; ZF: Cleared if ROM initialization is to be skipped
50; Set to continue ROM initialization
51; Corrupts registers:
52; Nothing
53;--------------------------------------------------------------------
54Initialize_ShouldSkip:
55 sti ; Enable interrupts
56 test BYTE [es:BDA.bKBFlgs1], (1<<2) ; Clear ZF if CTRL is held down
57 ret
58
59
60;--------------------------------------------------------------------
61; Initializes the BIOS variables and detects IDE drives.
62;
63; Initialize_AndDetectDrives
64; Parameters:
65; ES: BDA Segment
66; Returns:
67; DS: RAMVARS segment
68; Corrupts registers:
69; All
70;--------------------------------------------------------------------
71Initialize_AndDetectDrives:
72 call BootMenuPrint_InitializeDisplayContext
73 call DetectPrint_RomFoundAtSegment
74 call RamVars_Initialize
75 call Interrupts_InitializeInterruptVectors
76 call DetectDrives_FromAllIDEControllers
77 ; Fall to .StoreDptPointersToIntVectors
78
79;--------------------------------------------------------------------
80; .StoreDptPointersToIntVectors
81; Parameters:
82; DS: RAMVARS segment
83; ES: BDA and interrupt vector segment (zero)
84; Returns:
85; Nothing
86; Corrupts registers:
87; DX, DI
88;--------------------------------------------------------------------
89.StoreDptPointersToIntVectors:
90 mov dl, 80h
91 call RamVars_IsDriveHandledByThisBIOS
92 jnc SHORT .FindForDrive81h ; Store nothing if not our drive
93 call FindDPT_ForDriveNumber ; DPT to DS:DI
94 mov [es:HD0_DPT_POINTER_41h*4], di
95 mov [es:HD0_DPT_POINTER_41h*4+2], ds
96.FindForDrive81h:
97 inc dx
98 call RamVars_IsDriveHandledByThisBIOS
99 jnc SHORT .ResetDetectedDrives
100 call FindDPT_ForDriveNumber
101 mov [es:HD1_DPT_POINTER_46h*4], di
102 mov [es:HD1_DPT_POINTER_46h*4+2], ds
103 ; Fall to .ResetDetectedDrives
104
105;--------------------------------------------------------------------
106; .ResetDetectedDrives
107; Parameters:
108; DS: RAMVARS segment
109; Returns:
110; Nothing
111; Corrupts registers:
112; All
113;--------------------------------------------------------------------
114.ResetDetectedDrives:
115 call Idepack_FakeToSSBP
116 call AH0h_ResetHardDisksHandledByOurBIOS
117 add sp, BYTE SIZE_OF_FAKE_IDEPACK
118 ret
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