source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Boot/BootInfo.asm@ 86

Last change on this file since 86 was 83, checked in by krille_n_@…, 14 years ago

Minor size optimizations in various files.
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 : 6.1.2011
5; Author : Tomi Tilli,
6; : Krister Nordvall (optimizations)
7; Description : Functions for generating and accessing drive
8; information to be displayed on boot menu.
9
10; Section containing code
11SECTION .text
12
13;--------------------------------------------------------------------
14; Creates new BOOTNFO struct for detected hard disk.
15;
16; BootInfo_CreateForHardDisk
17; Parameters:
18; DL: Drive number
19; DS:DI: Ptr to Disk Parameter Table
20; ES:SI: Ptr to 512-byte ATA information read from the drive
21; Returns:
22; ES:BX: Ptr to BOOTNFO (if successful)
23; CF: Cleared if BOOTNFO created succesfully
24; Set if any error
25; Corrupts registers:
26; AX, BX, CX, DX
27;--------------------------------------------------------------------
28ALIGN JUMP_ALIGN
29BootInfo_CreateForHardDisk:
30 call BootInfo_GetOffsetToBX ; ES:BX now points to new BOOTNFO
31 call BootInfo_StoreSectorCount
32 jmp SHORT BootInfo_StoreDriveName
33
34
35;--------------------------------------------------------------------
36; Returns offset to BOOTNFO for wanted drive.
37;
38; BootInfo_GetOffsetToBX
39; Parameters:
40; DL: Drive number
41; DS: RAMVARS segment
42; Returns:
43; BX: Offset to BOOTNFO struct
44; Corrupts registers:
45; AX
46;--------------------------------------------------------------------
47ALIGN JUMP_ALIGN
48BootInfo_GetOffsetToBX:
49 mov bl, dl ; Copy drive number to BL
50 mov al, BOOTNFO_size ; Size of struct
51 sub bl, [RAMVARS.bFirstDrv] ; Drive number to index
52 mul bl ; AX = Offset inside BOOTNFO array
53 add ax, BOOTVARS.rgBootNfo ; Add offset to BOOTNFO array
54 xchg bx, ax ; Copy result to BX
55 ret
56
57
58;--------------------------------------------------------------------
59; Stores total sector count to BOOTNFO.
60;
61; BootInfo_StoreSectorCount
62; Parameters:
63; ES:BX: Ptr to BOOTNFO
64; ES:SI: Ptr to 512-byte ATA information read from the drive
65; DS:DI: Ptr to Disk Parameter Table
66; Returns:
67; CF: Cleared if variables stored succesfully
68; Set if any error
69; Corrupts registers:
70; AX, CX, DX
71;--------------------------------------------------------------------
72ALIGN JUMP_ALIGN
73BootInfo_StoreSectorCount:
74 push bx
75 call AtaID_GetTotalSectorCount ; Get to BX:DX:AX
76 mov cx, bx ; Now in CX:DX:AX
77 pop bx
78 mov [es:bx+BOOTNFO.twSectCnt], ax
79 mov [es:bx+BOOTNFO.twSectCnt+2], dx
80 mov [es:bx+BOOTNFO.twSectCnt+4], cx
81 clc
82 ret
83
84
85;--------------------------------------------------------------------
86; Stores drive name to BOOTNFO.
87;
88; BootInfo_StoreDriveName
89; Parameters:
90; ES:BX: Ptr to BOOTNFO
91; ES:SI: Ptr to 512-byte ATA information read from the drive
92; DS:DI: Ptr to Disk Parameter Table
93; Returns:
94; CF: Cleared if variables stored succesfully
95; Set if any error
96; Corrupts registers:
97; AX, CX
98;--------------------------------------------------------------------
99ALIGN JUMP_ALIGN
100BootInfo_StoreDriveName:
101 push ds
102 push si
103 push di
104
105 ; DS:SI to ATA source string
106 push es
107 pop ds
108 add si, BYTE ATA1.strModel
109
110 ; ES:DI to BOOTNFO destination string
111 lea di, [bx+BOOTNFO.szDrvName]
112
113 ; Read string
114 mov cx, LEN_BOOTNFO_DRV>>1
115 call BootInfo_StoreAtaString
116 pop di
117 pop si
118 pop ds
119 clc
120 ret
121
122;--------------------------------------------------------------------
123; Stores ATA string.
124; Byte ordering will be corrected and string will be STOP terminated.
125;
126; BootInfo_StoreAtaString
127; Parameters:
128; CX: Maximum number of WORDs to copy (without STOP)
129; DS:SI: Ptr to ATA string
130; ES:DI: Ptr to destination string
131; Returns:
132; Nothing
133; Corrupts registers:
134; AX, CX, SI, DI
135;--------------------------------------------------------------------
136ALIGN JUMP_ALIGN
137BootInfo_StoreAtaString:
138 lodsw ; Load WORD from DS:SI to AX
139 xchg al, ah ; Change byte order
140 call BootInfo_StoreAtaChar
141 jc SHORT .Return ; Return if invalid character
142 mov al, ah ; Write next char
143 call BootInfo_StoreAtaChar
144 jc SHORT .Return ; Return if invalid character
145 loop BootInfo_StoreAtaString ; Loop while words left
146.Return:
147 mov al, STOP ; End string with STOP
148 stosb
149 ret
150
151;--------------------------------------------------------------------
152; Stores ATA character.
153;
154; BootInfo_StoreAtaChar
155; Parameters:
156; AL: Character to store
157; ES:DI: Ptr to destination character
158; Returns:
159; DI: Incremented to next character
160; CF: Set if non writable ASCII character
161; Corrupts registers:
162; Nothing
163;--------------------------------------------------------------------
164ALIGN JUMP_ALIGN
165BootInfo_StoreAtaChar:
166 cmp al, 20h ; First allowed ASCII char?
167 jb SHORT .SkipStoring ; If below, end string
168 cmp al, 7Eh ; Last allowed ASCII char?
169 ja SHORT .SkipStoring ; If above, end string
170 stosb ; Store character
171 clc ; Clear CF to continue with next char
172 ret
173.SkipStoring:
174 stc
175 ret
176
177
178;--------------------------------------------------------------------
179; Finds BOOTNFO for drive and return total sector count.
180;
181; BootInfo_GetTotalSectorCount
182; Parameters:
183; DL: Drive number
184; DS: RAMVARS segment
185; Returns:
186; BX:DX:AX: 48-bit sector count
187; Corrupts registers:
188; Nothing
189;--------------------------------------------------------------------
190ALIGN JUMP_ALIGN
191BootInfo_GetTotalSectorCount:
192 push ds
193 call BootInfo_GetOffsetToBX
194 LOAD_BDA_SEGMENT_TO ds, ax
195 mov ax, [bx+BOOTNFO.twSectCnt]
196 mov dx, [bx+BOOTNFO.twSectCnt+2]
197 mov bx, [bx+BOOTNFO.twSectCnt+4]
198 pop ds
199 ret
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