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diff --git a/doc/html/emb-framebuffer-howto.html b/doc/html/emb-framebuffer-howto.html new file mode 100644 index 00000000..6fab9095 --- /dev/null +++ b/doc/html/emb-framebuffer-howto.html @@ -0,0 +1,234 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> +<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/doc/framebuffer-howto.doc:36 --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>Enabling the Linux Framebuffer</title> +<style type="text/css"><!-- +fn { margin-left: 1cm; text-indent: -1cm; } +a:link { color: #004faf; text-decoration: none } +a:visited { color: #672967; text-decoration: none } +body { background: #ffffff; color: black; } +--></style> +</head> +<body> + +<table border="0" cellpadding="0" cellspacing="0" width="100%"> +<tr bgcolor="#E5E5E5"> +<td valign=center> + <a href="index.html"> +<font color="#004faf">Home</font></a> + | <a href="classes.html"> +<font color="#004faf">All Classes</font></a> + | <a href="mainclasses.html"> +<font color="#004faf">Main Classes</font></a> + | <a href="annotated.html"> +<font color="#004faf">Annotated</font></a> + | <a href="groups.html"> +<font color="#004faf">Grouped Classes</font></a> + | <a href="functions.html"> +<font color="#004faf">Functions</font></a> +</td> +<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>Enabling the Linux Framebuffer</h1> + + + +<p> This is only a short guide. +See <a href="file:/usr/src/linux/README">/usr/src/linux/README</a> and +<a href="file:/usr/src/linux/Documentation/fb/">/usr/src/linux/Documentation/fb/</a> for detailed information. +There is also a detailed explanation at +<a href="http://www.linuxdoc.org/HOWTO/Framebuffer-HOWTO.html">http://www.linuxdoc.org/HOWTO/Framebuffer-HOWTO.html</a>. +<p> <ol type=1> +<li> Make sure that you have the Linux kernel source code in +<a href="file:/usr/src/linux/">/usr/src/linux/</a>. +<p> <li> Log in as root and <tt>cd</tt> <tt>/usr/src/linux</tt> +<p> <li> Configure the kernel: +<p> Run: +<pre> + make menuconfig +</pre> + +<p> Select "Code maturity level options" and set "Prompt for +development and/or incomplete code/drivers". +<p> Then select "Console drivers" and set "Support for frame buffer +devices" to built-in (even if it says EXPERIMENTAL). Then configure +the driver. Most modern graphics cards can use the "VESA VGA +graphics console"; use that or a driver that specifically matches +your video card. Finally, enable "Advanced low level driver options" +and make sure that 16 and 32 bpp packed pixel support are enabled. +<p> When you are finished, chose exit and save. +<p> <li> Compile the kernel +<p> First do: +<pre> + make dep +</pre> + +then: +<pre> + make bzImage +</pre> + +<p> The new kernel should now be in arch/i386/boot/bzImage. +<p> <li> Copy the kernel to the boot directory: +<pre> + cp arch/i386/boot/bzImage /boot/linux.vesafb +</pre> + +<p> <li> Edit /etc/lilo.conf. +<p> <b>Warning:</b> Keep a backup of <a href="file:/etc/lilo.conf">/etc/lilo.conf</a>, and have a rescue disk +available. If you make a mistake, the machine may not boot. +<p> The file <a href="file:/etc/lilo.conf">/etc/lilo.conf</a> specifies how the system boots. The +precise contents of the file varies from system to system. Here is +an example: +<pre> +# LILO configuration file +boot = /dev/hda3 +delay = 30 +image = /boot/vmlinuz + root = /dev/hda3 + label = Linux + read-only # Non-UMSDOS filesystems should be mounted read-only for checking +other=/dev/hda1 + label=nt + table=/dev/hda +</pre> + +<p> Make a new "image" section that is a copy of the first one, but with +<pre> + image = /boot/linux.vesafb +</pre> + +and +<pre> + label = Linux-vesafb +</pre> + +Place it just above the first image section. +<p> Add a line before the image section saying <tt>vga = 791</tt>. (Meaning +1024x768, 16 bpp.) +<p> With the above example, lilo.conf would now be: +<pre> +# LILO configuration file +boot = /dev/hda3 +delay = 30 +vga = 791 +image = /boot/linux.vesafb + root = /dev/hda3 + label = Linux-vesafb + read-only # Non-UMSDOS filesystems should be mounted read-only for checking +image = /boot/vmlinuz + root = /dev/hda3 + label = Linux + read-only # Non-UMSDOS filesystems should be mounted read-only for checking +other=/dev/hda1 + label=nt + table=/dev/hda +</pre> + +<p> Do not change any existing lines in the file; just add new ones. +<p> <li> To make the new changes take effect, run the lilo program: +<pre> + lilo +</pre> + +<p> <li> Reboot the system. You should now see a penguin logo while the +system is booting. +(Or more than one on a multi-processor machine.) +<p> <li> If it does not boot properly with the new kernel, you can boot with +the old kernel by entering the label of the old image section at +the LILO prompt. (with the example lilo.conf file, the old label is +Linux.) +<p> If that does not work (probably because of an error in lilo.conf), +boot the machine using your rescue disk, restore <a href="file:/etc/lilo.conf">/etc/lilo.conf</a> from backup and re-run lilo. +<p> <li> Testing: Here's a short program that opens the frame buffer and draws a +gradient-filled red square. +<p> <pre> +#include <unistd.h> +#include <stdio.h> +#include <fcntl.h> +#include <linux/fb.h> +#include <sys/mman.h> + +int main() +{ + int fbfd = 0; + struct fb_var_screeninfo vinfo; + struct fb_fix_screeninfo finfo; + long int screensize = 0; + char *fbp = 0; + int x = 0, y = 0; + long int location = 0; + + // Open the file for reading and writing + fbfd = open("/dev/fb0", O_RDWR); + if (!fbfd) { + printf("Error: cannot open framebuffer device.\n"); + exit(1); + } + printf("The framebuffer device was opened successfully.\n"); + + // Get fixed screen information + if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo)) { + printf("Error reading fixed information.\n"); + exit(2); + } + + // Get variable screen information + if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo)) { + printf("Error reading variable information.\n"); + exit(3); + } + + printf("%dx%d, %dbpp\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel ); + + // Figure out the size of the screen in bytes + screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8; + + // Map the device to memory + fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, + fbfd, 0); + if ((int)fbp == -1) { + printf("Error: failed to map framebuffer device to memory.\n"); + exit(4); + } + printf("The framebuffer device was mapped to memory successfully.\n"); + + x = 100; y = 100; // Where we are going to put the pixel + + // Figure out where in memory to put the pixel + for ( y = 100; y < 300; y++ ) + for ( x = 100; x < 300; x++ ) { + + location = (x+vinfo.xoffset) * (vinfo.bits_per_pixel/8) + + (y+vinfo.yoffset) * finfo.line_length; + + if ( vinfo.bits_per_pixel == 32 ) { + *(fbp + location) = 100; // Some blue + *(fbp + location + 1) = 15+(x-100)/2; // A little green + *(fbp + location + 2) = 200-(y-100)/5; // A lot of red + *(fbp + location + 3) = 0; // No transparency + } else { //assume 16bpp + int b = 10; + int g = (x-100)/6; // A little green + int r = 31-(y-100)/16; // A lot of red + unsigned short int t = r<<11 | g << 5 | b; + *((unsigned short int*)(fbp + location)) = t; + } + + } + munmap(fbp, screensize); + close(fbfd); + return 0; +} +</pre> + +</ol> +<p> +<!-- eof --> +<p><address><hr><div align=center> +<table width=100% cellspacing=0 border=0><tr> +<td>Copyright © 2007 +<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> +<td align=right><div align=right>TQt 3.3.8</div> +</table></div></address></body> +</html> |