167 lines
5.7 KiB
Plaintext
167 lines
5.7 KiB
Plaintext
Plex86/Bochs VGABios
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--------------------
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The goal of this project is to have a LGPL'd Video Bios in plex86
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and bochs.
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This VGA Bios is very specific to the emulated VGA card.
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It is NOT meant to drive a physical vga card.
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Install
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-------
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To compile the VGA Bios you will need :
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- gcc
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- bcc
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- as86
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- ld86
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Untar the archive, and type make. You should get a "vgabios.bin" file.
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Alternatively, you can use the binary file "vgabios-XXX.bin", i have
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compiled for you.
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Edit your plex86/bochs conf file, and modify the load-rom command in the
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VGA BIOS section, to point to the new vgabios.bin file.
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Debugging
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---------
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You can get a very basic debugging system: messages printed by the vgabios.
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You have to register the "unmapped" device driver in plex86 or bochs, and make
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sure it grabs port 0xfff0.
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Comment the #undef DEBUG at the beginning of vgabios.c.
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You can then use the "printf" function in the bios.
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Testing
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-------
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Look at the "testvga.c" file in the archive. This is a minimal Turbo C 2.0
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source file that calls a few int10 functions. Feel free to modify it to suit
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your needs.
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The VGA Bios in its current version has been very little tested.
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Copyright and License
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---------------------
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This program has been written by Christophe Bothamy
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It is protected by the GNU Lesser Public License, which you should
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have received a copy of along with this package.
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Reverse Engineering
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-------------------
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The VGA Bios has been written without reverse-engineering any existing Bios.
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Acknowledgment
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--------------
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The source code contains code ripped from rombios.c of plex86, written
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by Kevin Lawton <kevin2001@yahoo.com>
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The source code contains fonts from fntcol16.zip (c) by Joseph Gil avalable at :
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ftp://ftp.simtel.net/pub/simtelnet/msdos/screen/fntcol16.zip
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These fonts are public domain
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The source code is based on information taken from :
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- Kevin Lawton's vga card emulation for bochs/plex86
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- Ralf Brown's interrupts list avalaible at
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http://www.cs.cmu.edu/afs/cs/user/ralf/pub/WWW/files.html
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- Finn Thogersons' VGADOC4b available at http://home.worldonline.dk/~finth/
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- Michael Abrash's Graphics Programming Black Book
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- Francois Gervais' book "programmation des cartes graphiques cga-ega-vga"
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edited by sybex
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- DOSEMU 1.0.1 source code for several tables values and formulas
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Feedback
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--------
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Please report any bugs, comments, patches for this VGA Bios to cbothamy@free.fr
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You can find the latest release at : http://www.nongnu.org/vgabios/
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For any information on bochs, visit the website http://bochs.sourceforge.net/
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History
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vgabios-0.4c : Nov 06 2003
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- Christophe
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. fix font problem on initial screen of NT4 Loader
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vgabios-0.4b : Nov 04 2003
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- Volker
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. fix offset of character tables
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. optimizations of CRT controller accesses
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. VBE i/o registers changed to 0x01CE/CF
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(suggestion from Daniel Gimpelevich)
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. "noclear" flag stored in BIOS area
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. fix character height returned by get_font_info function
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vgabios-0.4a : Aug 17 2003
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- Volker
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. LFB flagged VBE modes removed
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. many bugfixes and optimizations
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. write character function implemeted for graphic modes
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. support for 15bpp, 16bpp, 24bpp and 32bpp VBE modes added
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. SVGA modes 0x6A added
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. VBE mode 0x102, 0x117, 0x118, 0x142 (Bochs specific)
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vgabios-0.3b : Nov 23 2002
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- Christophe
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. added lfb-mode numbers (patch from mathis)
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. updated the Makefile
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. removed display of copyrights.
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. changed the Copyright string to "LGPL VGABios developers"
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- Volker
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. set the cursor shape depending on the current font height
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. clear BL before calling int 0x10 function 0x1103 in vgabios_init_func
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. added some text font functions
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- Jeroen
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. Forced to new DISPI (0xb0c1) interface (requires latest bochs vbe code)
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. Added multibuffering support
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. Added new DISPI interface for: virt width, height, x offset, y offset
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. Added LFB modes (to be used with the vbe-lfb patch in bochs)
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see VBE_HAVE_LFB in vbe.c (currently default enabled)
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. updated TODO & docs for changes after bochs 1.4
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vgabios-0.3a : Mar 10 2002
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- Christophe
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. Fixed bug in function ah=13
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- Jeroen
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. updated vbebios implementation to new api
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. added vbe_display_api documentation
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. added 640x400x8, 640x480x8, 800x600x8, 1024x768
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(>640x480 needs a special bochs patch atm)
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. added 320x200x8 vbe support (uses the standard 320x200x8 vga mode to
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display, this allows for testing & having something on screen as well,
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at least until bochs host side display is up & running)
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. adding lfbprof (vbe) testprogram (+some small fixes to it)
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. merging with vbebios 0.2
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vgabios-0.2b : Nov 19 2001
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- Christophe
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. Fixed bug in function ah=13
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vgabios-0.2a : Nov 09 2001
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- Christophe
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. Included bugfix from techt@pikeonline.net about grayscale summing
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. Added the "IBM" string at org 0x1e as Bart Oldeman suggested
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. Fixed DS and ES that where inverted in the int10 parameters list!
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. The following have been implemented :
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- function ax=1a00, ax=1a01, ah=1b
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- function ax=1130
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. Added debug messages for unimplemented/unknown functions
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Must be compiled with DEBUG defined. The output is trapped
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by the unknown-ioport driver of plex/bochs (port 0xfff0 is used)
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vgabios-0.1a : May 8 2001
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- Christophe
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. First release. The work has been focused only on text mode.
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. The following have been implemented :
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- inits
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- int 10 handler
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- functions ah=00, ah=01, ah=02, ah=03, ah=05, ah=06, ah=07, ah=08
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ah=09, ah=0a, ah=0e, ah=0f, ax=1000, ax=1001, ax=1002, ax=1003
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ax=1007, ax=1008, ax=1009, ax=1010, ax=1012, ax=1013, ax=1015
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ax=1017, ax=1018, ax=1019, ax=101a, ax=101b, ah=12 bl=10,
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ah=12 bl=30, ah=12 bl=31, ah=12 bl=32, ah=12 bl=33, ah=12 bl=34
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ah=13
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