source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/Initialize.asm @ 262

Last change on this file since 262 was 262, checked in by gregli@…, 12 years ago

More optimizations. Merged RamVars_IsFunction/DriveHandledByThisBIOS in with FindDPT_ForDriveNumber, since they are often used together, making a returned NULL DI pointer indicate a foreign drive in many places. Revamped the iteration done in the handlers for int13/0dh and int13h/0h. Added serial specific print string during drive detection.

File size: 2.8 KB
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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:           ; unused entrypoint ok
20    pushf
21    push    es
22    push    ds
23    ePUSHA
24
25    LOAD_BDA_SEGMENT_TO es, ax
26    sti                                     ; Enable interrupts
27    test    BYTE [es:BDA.bKBFlgs1], (1<<2)  ; Clears ZF if CTRL is held down
28    jnz     SHORT .SkipRomInitialization
29
30    ; Install INT 19h handler (boot loader) where drives are detected
31    mov     al, BIOS_BOOT_LOADER_INTERRUPT_19h
32    mov     si, Int19h_BootLoaderHandler
33    call    Interrupts_InstallHandlerToVectorInALFromCSSI
34
35.SkipRomInitialization:
36    ePOPA
37    pop     ds
38    pop     es
39    popf
40    retf
41
42
43;--------------------------------------------------------------------
44; Initializes the BIOS variables and detects IDE drives.
45;
46; Initialize_AndDetectDrives
47;   Parameters:
48;       ES:     BDA Segment
49;   Returns:
50;       DS:     RAMVARS segment
51;   Corrupts registers:
52;       All
53;--------------------------------------------------------------------
54Initialize_AndDetectDrives:
55    call    BootMenuPrint_InitializeDisplayContext
56    call    DetectPrint_RomFoundAtSegment
57    call    RamVars_Initialize
58    call    Interrupts_InitializeInterruptVectors
59    call    DetectDrives_FromAllIDEControllers
60    ; Fall to .StoreDptPointersToIntVectors
61
62;--------------------------------------------------------------------
63; .StoreDptPointersToIntVectors
64;   Parameters:
65;       DS:     RAMVARS segment
66;       ES:     BDA and interrupt vector segment (zero)
67;   Returns:
68;       Nothing
69;   Corrupts registers:
70;       DX, DI
71;--------------------------------------------------------------------
72.StoreDptPointersToIntVectors:
73    mov     dl, 80h
74    call    FindDPT_ForDriveNumberInDL   ; DPT to DS:DI
75    jc      SHORT .FindForDrive81h  ; Store nothing if not our drive
76    mov     [es:HD0_DPT_POINTER_41h*4], di
77    mov     [es:HD0_DPT_POINTER_41h*4+2], ds
78.FindForDrive81h:
79    inc     dx
80    call    FindDPT_ForDriveNumberInDL
81    jc      SHORT .ResetDetectedDrives
82    mov     [es:HD1_DPT_POINTER_46h*4], di
83    mov     [es:HD1_DPT_POINTER_46h*4+2], ds
84    ; Fall to .ResetDetectedDrives
85
86;--------------------------------------------------------------------
87; .ResetDetectedDrives
88;   Parameters:
89;       DS:     RAMVARS segment
90;       ES:     BDA and interrupt vector segment (zero)
91;   Returns:
92;       Nothing
93;   Corrupts registers:
94;       All, except DS and ES
95;--------------------------------------------------------------------
96.ResetDetectedDrives:
97    call    Idepack_FakeToSSBP
98    call    AH0h_ResetHardDisksHandledByOurBIOS
99    add     sp, BYTE EXTRA_BYTES_FOR_INTPACK
100    ret
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