1Plex86/Bochs VGABios
2--------------------
3
4The goal of this project is to have a LGPL'd Video Bios in plex86,
5Bochs and qemu.
6This VGA Bios is very specific to the emulated VGA card.
7It is NOT meant to drive a physical vga card.
8
9
10Cirrus SVGA extension
11---------------------
12
13The Cirrus SVGA extension is designed for the Cirrus emulation in Bochs and
14qemu. The initial patch for the Cirrus extension has been written by Makoto
15Suzuki (suzu).
16
17
18Install
19-------
20To compile the VGA Bios you will need :
21- gcc
22- bcc
23- as86
24- ld86
25
26Untar the archive, and type make. You should get a "VGABIOS-lgpl-latest.bin"
27file. Alternatively, you can use the binary file "VGABIOS-lgpl-latest.bin",
28i have compiled for you.
29
30Edit your plex86/bochs conf file, and modify the load-rom command in the
31VGA BIOS section, to point to the new vgabios image file.
32
33
34Debugging
35---------
36You can get a very basic debugging system: messages printed by the vgabios.
37You have to register the "unmapped" device driver in plex86 or bochs, and make
38sure it grabs port 0xfff0.
39
40Comment the #undef DEBUG at the beginning of vgabios.c.
41You can then use the "printf" function in the bios.
42
43
44Testing
45-------
46Look at the "testvga.c" file in the archive. This is a minimal Turbo C 2.0
47source file that calls a few int10 functions. Feel free to modify it to suit
48your needs.
49
50
51Copyright and License
52---------------------
53This program has been written by Christophe Bothamy
54It is protected by the GNU Lesser Public License, which you should
55have received a copy of along with this package.
56
57
58Reverse Engineering
59-------------------
60The VGA Bios has been written without reverse-engineering any existing Bios.
61
62
63Acknowledgment
64--------------
65The source code contains code ripped from rombios.c of plex86, written
66by Kevin Lawton <kevin2001@yahoo.com>
67
68The source code contains fonts from fntcol16.zip (c) by Joseph Gil avalable at :
69ftp://ftp.simtel.net/pub/simtelnet/msdos/screen/fntcol16.zip
70These fonts are public domain
71
72The source code is based on information taken from :
73- Kevin Lawton's vga card emulation for bochs/plex86
74- Ralf Brown's interrupts list avalaible at
75 http://www.cs.cmu.edu/afs/cs/user/ralf/pub/WWW/files.html
76- Finn Thogersons' VGADOC4b available at http://home.worldonline.dk/~finth/
77- Michael Abrash's Graphics Programming Black Book
78- Francois Gervais' book "programmation des cartes graphiques cga-ega-vga"
79 edited by sybex
80- DOSEMU 1.0.1 source code for several tables values and formulas
81
82
83Feedback
84--------
85Please report any bugs, comments, patches for this VGA Bios to info@vruppert.de
86You can find the latest release at : http://www.nongnu.org/vgabios/
87For any information on bochs, visit the website http://bochs.sourceforge.net/
88For any information on qemu, visit the website http://fabrice.bellard.free.fr/qemu/
89
90
91History
92-------
93vgabios-0.6b : May 30 2008
94 - Volker
95 . added PCI data structure for the Cirrus VGABIOS images
96 . minor bugfixes in biossums utility, VBE support and makefile
97
98vgabios-0.6a : Aug 19 2006
99 - Volker
100 . added minimal support for the video parameter table (VPT)
101 . Cirrus SVGA now supports the "no clear" bit in Cirrus and VESA mode
102 . Bochs VBE protected mode interface improved
103 . save/restore video state support for Bochs VBE and standard VGA added
104 . generate vbetables.h dynamicly
105 . VBE video memory increased to 8 MB (VBE dispi ID changed to B0C4)
106 . lots of 4bpp VBE fixes (all 4bpp VBE modes now enabled)
107 . VGA compatible setup for VBE modes added
108
109vgabios-0.5d : Dec 29 2005
110 - Volker
111 . Bochs VBE protected mode interface added (based on a patch by malc@pulsesoft.com)
112 . biossums utility now supports VGABIOS sizes up to 64 kBytes
113 . VGA mode 0x11: all color planes must be enabled in this 2-color VGA mode
114
115vgabios-0.5c : Jul 07 2005
116 - Volker
117 . BIOS configuration word usually reports initial mode 80x25 color text
118 . vgabios function 0x0e (write teletype): linefeed (0x0a) only increments the
119 cursor row value
120
121vgabios-0.5b : May 24 2005
122 - Volker
123 . fixed return value for the default case in the VBE section (non-debug mode)
124 . removed unused stuff
125
126vgabios-0.5a : Mar 07 2005
127 - Volker
128 . Cirrus SVGA extension (initial patches from Makoto Suzuki, improvements
129 from Fabrice Bellard)
130 . vgabios image size is now exactly 32k with a checksum
131 . a lot of vgabios and vbe functions rewritten in assembler
132 . dynamicly generated VBE mode info list
133 . write character function for CGA and LINEAR8 modes
134 . read/write graphics pixel for some graphics modes
135 . text scroll feature for some graphics modes
136 . VBE 8-bit DAC support
137
138vgabios-0.4c : Nov 06 2003
139 - Christophe
140 . fix font problem on initial screen of NT4 Loader
141
142vgabios-0.4b : Nov 04 2003
143 - Volker
144 . fix offset of character tables
145 . optimizations of CRT controller accesses
146 . VBE i/o registers changed to 0x01CE/CF
147 (suggestion from Daniel Gimpelevich)
148 . "noclear" flag stored in BIOS area
149 . fix character height returned by get_font_info function
150
151vgabios-0.4a : Aug 17 2003
152 - Volker
153 . VBE mode search rewritten (VBE modes with LFB bit removed)
154 . many bugfixes and optimizations
155 . write character function implemented for graphics modes
156 . support for 15bpp, 16bpp, 24bpp and 32bpp VBE modes added
157 . SVGA mode 0x6A added
158 . VBE modes 0x102, 0x117, 0x118 and 0x142 (Bochs specific)
159
160vgabios-0.3b : Nov 23 2002
161 - Christophe
162 . added lfb-mode numbers (patch from mathis)
163 . updated the Makefile
164 . removed display of copyrights.
165 . changed the Copyright string to "LGPL VGABios developers"
166 - Volker
167 . set the cursor shape depending on the current font height
168 . clear BL before calling int 0x10 function 0x1103 in vgabios_init_func
169 . added some text font functions
170 - Jeroen
171 . Forced to new DISPI (0xb0c1) interface (requires latest bochs vbe code)
172 . Added multibuffering support
173 . Added new DISPI interface for: virt width, height, x offset, y offset
174 . Added LFB modes (to be used with the vbe-lfb patch in bochs)
175 see VBE_HAVE_LFB in vbe.c (currently default enabled)
176 . updated TODO & docs for changes after bochs 1.4
177
178vgabios-0.3a : Mar 10 2002
179 - Christophe
180 . Fixed bug in function ah=13
181 - Jeroen
182 . updated vbebios implementation to new api
183 . added vbe_display_api documentation
184 . added 640x400x8, 640x480x8, 800x600x8, 1024x768
185 (>640x480 needs a special bochs patch atm)
186 . added 320x200x8 vbe support (uses the standard 320x200x8 vga mode to
187 display, this allows for testing & having something on screen as well,
188 at least until bochs host side display is up & running)
189 . adding lfbprof (vbe) testprogram (+some small fixes to it)
190 . merging with vbebios 0.2
191
192vgabios-0.2b : Nov 19 2001
193 - Christophe
194 . Fixed bug in function ah=13
195
196vgabios-0.2a : Nov 09 2001
197 - Christophe
198 . Included bugfix from techt@pikeonline.net about grayscale summing
199 . Added the "IBM" string at org 0x1e as Bart Oldeman suggested
200 . Fixed DS and ES that where inverted in the int10 parameters list!
201 . The following have been implemented :
202 - function ax=1a00, ax=1a01, ah=1b
203 - function ax=1130
204 . Added debug messages for unimplemented/unknown functions
205 Must be compiled with DEBUG defined. The output is trapped
206 by the unknown-ioport driver of plex/bochs (port 0xfff0 is used)
207
208vgabios-0.1a : May 8 2001
209 - Christophe
210 . First release. The work has been focused only on text mode.
211 . The following have been implemented :
212 - inits
213 - int 10 handler
214 - functions ah=00, ah=01, ah=02, ah=03, ah=05, ah=06, ah=07, ah=08
215 ah=09, ah=0a, ah=0e, ah=0f, ax=1000, ax=1001, ax=1002, ax=1003
216 ax=1007, ax=1008, ax=1009, ax=1010, ax=1012, ax=1013, ax=1015
217 ax=1017, ax=1018, ax=1019, ax=101a, ax=101b, ah=12 bl=10,
218 ah=12 bl=30, ah=12 bl=31, ah=12 bl=32, ah=12 bl=33, ah=12 bl=34
219 ah=13
220