Return to vga CVS log

Up to [Plan 9 NeXT] / lucent / sys / man / 3

Annotation of lucent/sys/man/3/vga, revision 1.1.1.1

1.1       root        1: .TH VGA 3 
                      2: .SH NAME
                      3: vga \- VGA controller device
                      4: .SH SYNOPSIS
                      5: .nf
                      6: .B bind #v /dev
                      7: 
                      8: .B /dev/vgactl
                      9: .B /dev/vgaiob
                     10: .B /dev/vgaiow
                     11: .B /dev/vgaiol
                     12: .fi
                     13: .SH DESCRIPTION
                     14: The VGA device allows configuration of a graphics controller
                     15: on a PC.
                     16: .B Vgactl
                     17: allows control over higher-level settings such as display height, width, depth,
                     18: controller and hardware-cursor type.
                     19: .BR Vgaiob ,
                     20: .B vgaiow 
                     21: and
                     22: .B vgaiol
                     23: allow control over individual 8-bit, 16-bit and 32-bit
                     24: x86
                     25: I/O-ports respectively, such as those
                     26: used to implement configuration and setup registers on a VGA controller card.
                     27: These functions are normally carried out by
                     28: .IR vga (8).
                     29: .PP
                     30: Writes to
                     31: .B vgactl
                     32: are of the form
                     33: .RI ` attribute\ value '.
                     34: Valid attributes are
                     35: .TP
                     36: .I size
                     37: .I value
                     38: is 
                     39: .IB 'X x Y x Z'
                     40: , where
                     41: .IR X ,
                     42: .I Y
                     43: and
                     44: .I Z
                     45: are numbers that tell the kernel the width and
                     46: height of the screen in pixels and the number of
                     47: bits per pixel.
                     48: .TP
                     49: .I type
                     50: tells the kernel which type of controller is
                     51: being used, mainly to enable the correct code for display-memory bank switching
                     52: at resolutions greater than 640x480x1. The names
                     53: .IR vga ,
                     54: .IR clgd542x ,
                     55: .IR et4000 ,
                     56: .IR mach32 ,
                     57: and
                     58: .I s3
                     59: are supported for
                     60: .IR value .
                     61: .IP
                     62: Note that this list does not indicate the full set of VGA chips
                     63: supported. For example,
                     64: .I s3
                     65: includes the 86C801/5, 86C928, Vision864, and Vision964.
                     66: It is the job of
                     67: .IR vga (8)
                     68: to recognize which particular chip is being used and to initialize it
                     69: appropriately.
                     70: .TP
                     71: .I hwgc
                     72: tells the kernel to use a particular type of hardware graphics cursor.
                     73: .IR Bt485hwgc ,
                     74: .IR et4000hwgc ,
                     75: .I s3hwgc
                     76: and
                     77: .IR tvp3020hwgc ,
                     78: are currently recognized values.
                     79: A value of
                     80: .I off
                     81: reverts to using the software cursor.
                     82: .PP
                     83: Reading
                     84: .B vgactl
                     85: returns the current settings, one per line.
                     86: .SH EXAMPLES
                     87: The following reverts to using the software graphics
                     88: cursor
                     89: .EX
                     90: 
                     91:        echo -n 'hwgc off' >/dev/vgactl
                     92: 
                     93: .EE
                     94: Sample code to read an
                     95: x86
                     96: 8-bit I/O port
                     97: .EX
                     98: 
                     99:        uchar
                    100:        inportb(long port)
                    101:        {
                    102:                uchar data;
                    103:        
                    104:                if(iobfd == -1)
                    105:                        iobfd = open("#v/vgaiob", ORDWR);
                    106:        
                    107:                seek(iobfd, port, 0);
                    108:                if(read(iobfd, &data, sizeof(data)) != sizeof(data))
                    109:                        error("inportb(0x%4.4x): %r\n", port);
                    110:                return data;
                    111:        }
                    112: 
                    113: .EE
                    114: .SH SOURCE
                    115: .B /sys/src/9/pc/devvga.c
                    116: .SH SEE ALSO
                    117: .IR vga (8)
                    118: .SH BUGS
                    119: There should be some restriction on the range of valid ports.
                    120: .PP
                    121: There should be support for the hardware graphics cursor on the
                    122: .I clgd54[23]x
                    123: VGA controller chips.
                    124: .PP
                    125: The hardware graphics cursor on the
                    126: .I et4000
                    127: does not work in 2x8-bit mode.

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.