source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Boot/BootInfo.asm@ 51

Last change on this file since 51 was 3, checked in by Tomi Tilli, 14 years ago
File size: 5.5 KB
Line 
1; File name : BootInfo.asm
2; Project name : IDE BIOS
3; Created date : 16.3.2010
4; Last update : 9.4.2010
5; Author : Tomi Tilli
6; Description : Functions for generating and accessing drive
7; information to be displayed on boot menu.
8
9; Section containing code
10SECTION .text
11
12;--------------------------------------------------------------------
13; Creates new BOOTNFO struct for detected hard disk.
14;
15; BootInfo_CreateForHardDisk
16; Parameters:
17; DL: Drive number
18; DS:DI: Ptr to Disk Parameter Table
19; ES:SI: Ptr to 512-byte ATA information read from the drive
20; Returns:
21; ES:BX: Ptr to BOOTNFO (if successful)
22; CF: Cleared if BOOTNFO created succesfully
23; Set if any error
24; Corrupts registers:
25; AX, BX, CX, DX
26;--------------------------------------------------------------------
27ALIGN JUMP_ALIGN
28BootInfo_CreateForHardDisk:
29 call BootInfo_GetOffsetToBX ; ES:BX now points to new BOOTNFO
30 call BootInfo_StoreSectorCount
31 jmp SHORT BootInfo_StoreDriveName
32
33
34;--------------------------------------------------------------------
35; Returns offset to BOOTNFO for wanted drive.
36;
37; BootInfo_GetOffsetToBX
38; Parameters:
39; DL: Drive number
40; DS: RAMVARS segment
41; Returns:
42; BX: Offset to BOOTNFO struct
43; Corrupts registers:
44; AX
45;--------------------------------------------------------------------
46ALIGN JUMP_ALIGN
47BootInfo_GetOffsetToBX:
48 mov bl, dl ; Copy drive number to BL
49 mov al, BOOTNFO_size ; Size of struct
50 sub bl, [RAMVARS.bFirstDrv] ; Drive number to index
51 mul bl ; AX = Offset inside BOOTNFO array
52 mov bx, ax ; Copy offset to BX
53 add bx, BOOTVARS.rgBootNfo ; Add offset to BOOTNFO array
54 ret
55
56
57;--------------------------------------------------------------------
58; Stores total sector count to BOOTNFO.
59;
60; BootInfo_StoreSectorCount
61; Parameters:
62; ES:BX: Ptr to BOOTNFO
63; ES:SI: Ptr to 512-byte ATA information read from the drive
64; DS:DI: Ptr to Disk Parameter Table
65; Returns:
66; CF: Cleared if variables stored succesfully
67; Set if any error
68; Corrupts registers:
69; AX, CX, DX
70;--------------------------------------------------------------------
71ALIGN JUMP_ALIGN
72BootInfo_StoreSectorCount:
73 push bx
74 call AtaID_GetTotalSectorCount ; Get to BX:DX:AX
75 mov cx, bx ; Now in CX:DX:AX
76 pop bx
77 mov [es:bx+BOOTNFO.twSectCnt], ax
78 mov [es:bx+BOOTNFO.twSectCnt+2], dx
79 mov [es:bx+BOOTNFO.twSectCnt+4], cx
80 clc
81 ret
82
83
84;--------------------------------------------------------------------
85; Stores drive name to BOOTNFO.
86;
87; BootInfo_StoreDriveName
88; Parameters:
89; ES:BX: Ptr to BOOTNFO
90; ES:SI: Ptr to 512-byte ATA information read from the drive
91; DS:DI: Ptr to Disk Parameter Table
92; Returns:
93; CF: Cleared if variables stored succesfully
94; Set if any error
95; Corrupts registers:
96; AX, CX
97;--------------------------------------------------------------------
98ALIGN JUMP_ALIGN
99BootInfo_StoreDriveName:
100 push ds
101 push si
102 push di
103
104 ; DS:SI to ATA source string
105 push es
106 pop ds
107 add si, BYTE ATA1.strModel
108
109 ; ES:DI to BOOTNFO destination string
110 lea di, [bx+BOOTNFO.szDrvName]
111
112 ; Read string
113 mov cx, LEN_BOOTNFO_DRV>>1
114 call BootInfo_StoreAtaString
115 pop di
116 pop si
117 pop ds
118 clc
119 ret
120
121;--------------------------------------------------------------------
122; Stores ATA string.
123; Byte ordering will be corrected and string will be STOP terminated.
124;
125; BootInfo_StoreAtaString
126; Parameters:
127; CX: Maximum number of WORDs to copy (without STOP)
128; DS:SI: Ptr to ATA string
129; ES:DI: Ptr to destination string
130; Returns:
131; Nothing
132; Corrupts registers:
133; AX, CX, SI, DI
134;--------------------------------------------------------------------
135ALIGN JUMP_ALIGN
136BootInfo_StoreAtaString:
137 lodsw ; Load WORD from DS:SI to AX
138 xchg al, ah ; Change byte order
139 call BootInfo_StoreAtaChar
140 jc SHORT .Return ; Return if invalid character
141 mov al, ah ; Write next char
142 call BootInfo_StoreAtaChar
143 jc SHORT .Return ; Return if invalid character
144 loop BootInfo_StoreAtaString ; Loop while words left
145.Return:
146 mov al, STOP ; End string with STOP
147 stosb
148 ret
149
150;--------------------------------------------------------------------
151; Stores ATA character.
152;
153; BootInfo_StoreAtaChar
154; Parameters:
155; AL: Character to store
156; ES:DI: Ptr to destination character
157; Returns:
158; DI: Incremented to next character
159; CF: Set if non writable ASCII character
160; Corrupts registers:
161; Nothing
162;--------------------------------------------------------------------
163ALIGN JUMP_ALIGN
164BootInfo_StoreAtaChar:
165 cmp al, 20h ; First allowed ASCII char?
166 jb SHORT .SkipStoring ; If below, end string
167 cmp al, 7Eh ; Last allowed ASCII char?
168 ja SHORT .SkipStoring ; If above, end string
169 stosb ; Store character
170 clc ; Clear CF to continue with next char
171 ret
172.SkipStoring:
173 stc
174 ret
175
176
177;--------------------------------------------------------------------
178; Finds BOOTNFO for drive and return total sector count.
179;
180; BootInfo_GetTotalSectorCount
181; Parameters:
182; DL: Drive number
183; DS: RAMVARS segment
184; Returns:
185; BX:DX:AX: 48-bit sector count
186; Corrupts registers:
187; Nothing
188;--------------------------------------------------------------------
189ALIGN JUMP_ALIGN
190BootInfo_GetTotalSectorCount:
191 push ds
192 call BootInfo_GetOffsetToBX
193 LOAD_BDA_SEGMENT_TO ds, ax
194 mov ax, [bx+BOOTNFO.twSectCnt]
195 mov dx, [bx+BOOTNFO.twSectCnt+2]
196 mov bx, [bx+BOOTNFO.twSectCnt+4]
197 pop ds
198 ret
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