source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/Tools/Address.asm@ 580

Last change on this file since 580 was 568, checked in by krille_n_@…, 10 years ago

Changes:

  • SerDrive: Using named pipe mode (serdrive -p) now works under Windows XP/2000/Server 2003.
  • checksum.pl: Added a compatibility fix for 3Com 3C503 cards.
  • XTIDECFG will now scan every possible segment address to find and load the BIOS and/or its settings from EEPROM. This should simplify things for people using combined option ROMs.
  • Fixed a bug from r521 in BootSector.asm where the BIOS would not display a timeout error if it failed to load the boot sector from harddrive.
  • Fixed a bug from r541 in CompatibleDPT.asm where CompatibleDPT_CreateDeviceParameterTableExtensionToESBXfromDPTinDSSI would generate an invalid checksum in the DPTE.
  • Optimizations and other fixes.
File size: 6.9 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Functions for address translations.
3
4;
5; XTIDE Universal BIOS and Associated Tools
6; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 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; Address_ExtractLCHSparametersFromOldInt13hAddress
25; Parameters:
26; CH: Cylinder number, bits 7...0
27; CL: Bits 7...6: Cylinder number bits 9 and 8
28; Bits 5...0: Sector number
29; DH: Head number
30; Returns:
31; BL: Sector number (1...63)
32; BH: Head number (0...255)
33; CX: Cylinder number (0...1023)
34; Corrupts registers:
35; Nothing
36;--------------------------------------------------------------------
37ALIGN JUMP_ALIGN
38Address_ExtractLCHSparametersFromOldInt13hAddress:
39 mov bl, 3Fh ; Load sector number mask
40 and bl, cl ; Sector number now in BL
41 sub cl, bl ; Remove from cylinder number high
42 eROL_IM cl, 2 ; High bits to beginning
43 mov bh, dh ; Copy Head number
44 xchg cl, ch ; Cylinder number now in CX
45 ret
46
47
48;---------------------------------------------------------------------
49; Converts LARGE addressing mode LCHS parameters to IDE P-CHS parameters.
50; PCylinder = (LCylinder << n) + (LHead / PHeadCount)
51; PHead = LHead % PHeadCount
52; PSector = LSector
53;
54; ConvertLargeModeLCHStoPCHS:
55; Parameters:
56; BL: Sector number (1...63)
57; BH: Head number (0...239)
58; CX: Cylinder number (0...1023)
59; DS:DI: Ptr to Disk Parameter Table
60; Returns:
61; BL: Sector number (1...63)
62; BH: Head number (0...15)
63; CX: Cylinder number (0...16382)
64; Corrupts registers:
65; AX, DX
66;--------------------------------------------------------------------
67ALIGN JUMP_ALIGN
68ConvertLargeModeLCHStoPCHS:
69 ; LHead / PHeadCount and LHead % PHeadCount
70 eMOVZX ax, bh ; Copy L-CHS Head number to AX
71 div BYTE [di+DPT.bPchsHeads]; AL = LHead / PHeadCount, AH = LHead % PHeadCount
72 mov bh, ah ; Copy P-CHS Head number to BH
73 xor ah, ah ; AX = LHead / PHeadCount
74
75 ; (LCylinder << n) + (LHead / PHeadCount)
76 mov dx, cx ; Copy L-CHS Cylinder number to DX
77 mov cl, MASKL_DPT_CHS_SHIFT_COUNT ; Load shift count mask
78 and cl, [di+DPT.bFlagsLow] ; Shift count now in CL
79 shl dx, cl ; DX = LCylinder << n
80 add ax, dx ; AX = P-CHS Cylinder number
81 xchg cx, ax ; Move P-CHS Cylinder number to CX
82DoNotConvertLCHS:
83 ret
84
85; *FIXME* The above function description doesn't match the code.
86; If CX has a maximum value of 1023 on entry then there is no way CX can be 16382 on return.
87; 1023 SHL 3 (MASKL_DPT_CHS_SHIFT_COUNT) is 8184. With the addition of AX (at most 255?)
88; the result is 8439.
89
90;--------------------------------------------------------------------
91; Address_OldInt13hAddressToIdeAddress
92; Parameters:
93; CH: Cylinder number, bits 7...0
94; CL: Bits 7...6: Cylinder number bits 9 and 8
95; Bits 5...0: Starting sector number (1...63)
96; DH: Starting head number (0...255)
97; DS:DI: Ptr to DPT
98; Returns:
99; BL: LBA Low Register / Sector Number Register (LBA 7...0)
100; CL: LBA Mid Register / Low Cylinder Register (LBA 15...8)
101; CH: LBA High Register / High Cylinder Register (LBA 23...16)
102; BH: Drive and Head Register (LBA 27...24)
103; Corrupts registers:
104; AX, DX
105;--------------------------------------------------------------------
106ALIGN JUMP_ALIGN
107Address_OldInt13hAddressToIdeAddress:
108 call Address_ExtractLCHSparametersFromOldInt13hAddress
109 mov al, [di+DPT.bFlagsLow]
110 and al, MASKL_DPT_TRANSLATEMODE
111
112;;; 0: ADDRESSING_MODE_NORMAL
113 jz SHORT DoNotConvertLCHS
114
115;;; 1: ADDRESSING_MODE_LARGE
116 test al, FLGL_DPT_ASSISTED_LBA
117 jz SHORT ConvertLargeModeLCHStoPCHS
118
119;;; 2: ADDRESSING_MODE_ASSISTED_LBA
120 ; Fall to ConvertAssistedLBAModeLCHStoLBARegisterValues
121
122
123;---------------------------------------------------------------------
124; Converts LCHS parameters to 28-bit LBA address.
125; Only 24-bits are used since LHCS to LBA28 conversion has 8.4GB limit.
126; LBA = ((cylToSeek*headsPerCyl+headToSeek)*sectPerTrack)+sectToSeek-1
127; headsPerCyl and sectPerTrack are the current translation values (L-CHS).
128;
129; Returned address is in same registers that
130; DoNotConvertLCHS and ConvertLargeModeLCHStoPCHS returns.
131;
132; ConvertAssistedLBAModeLCHStoLBARegisterValues:
133; Parameters:
134; BL: Sector number (1...63)
135; BH: Head number (0...254)
136; CX: Cylinder number (0...1023)
137; DS:DI: Ptr to Disk Parameter Table
138; Returns:
139; BL: LBA Low Register / Sector Number Register (LBA 7...0)
140; CL: LBA Mid Register / Low Cylinder Register (LBA 15...8)
141; CH: LBA High Register / High Cylinder Register (LBA 23...16)
142; BH: Drive and Head Register (LBA 27...24)
143; Corrupts registers:
144; AX, DX
145;--------------------------------------------------------------------
146ConvertAssistedLBAModeLCHStoLBARegisterValues:
147 ; cylToSeek*headsPerCyl (18-bit result)
148 ; Max = 1023 * 255 = 260,865 = 3FB01h
149 mov ax, LBA_ASSIST_SPT ; Load Sectors per Track
150 xchg cx, ax ; Cylinder number to AX, Sectors per Track to CX
151%ifdef USE_386
152 movzx dx, [di+DPT.bLchsHeads]
153%else
154 cwd
155 mov dl, [di+DPT.bLchsHeads]
156%endif
157 mul dx ; DX:AX = cylToSeek*headsPerCyl
158
159 ; +=headToSeek (18-bit result)
160 ; Max = 260,865 + 254 = 261,119 = 3FBFFh
161 add al, bh ; Add Head number to DX:AX
162 adc ah, dh ; DH = Zero after previous multiplication
163 adc dl, dh
164
165 ; *=sectPerTrack (18-bit by 6-bit multiplication with 24-bit result)
166 ; Max = 261,119 * 63 = 16,450,497 = FB03C1h
167 xchg ax, dx ; Hiword to AX, loword to DX
168 mul cl ; AX = hiword * Sectors per Track
169 mov bh, al ; Backup hiword * Sectors per Track
170 xchg ax, dx ; Loword back to AX
171 mul cx ; DX:AX = loword * Sectors per Track
172 add dl, bh ; DX:AX = (cylToSeek*headsPerCyl+headToSeek)*sectPerTrack
173
174 ; +=sectToSeek-1 (24-bit result)
175 ; Max = 16,450,497 + 63 - 1 = 16,450,559 = FB03FFh
176 xor bh, bh ; Sector number now in BX
177 dec bx ; sectToSeek-=1
178 add ax, bx ; Add to loword
179 adc dl, bh ; Add possible carry to byte2, BH=zero
180
181 ; Copy DX:AX to proper return registers
182 xchg bx, ax ; BL = Sector Number Register (LBA 7...0)
183 mov cl, bh ; Low Cylinder Register (LBA 15...8)
184 mov ch, dl ; High Cylinder Register (LBA 23...16)
185 mov bh, dh ; Drive and Head Register (LBA 27...24)
186 ret
Note: See TracBrowser for help on using the repository browser.