| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | Software cursor for VGA    by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz> | 
|  | 2 | =======================    and Martin Mares <mj@atrey.karlin.mff.cuni.cz> | 
|  | 3 |  | 
|  | 4 | Linux now has some ability to manipulate cursor appearance. Normally, you | 
|  | 5 | can set the size of hardware cursor (and also work around some ugly bugs in | 
|  | 6 | those miserable Trident cards--see #define TRIDENT_GLITCH in drivers/video/ | 
|  | 7 | vgacon.c). You can now play a few new tricks:  you can make your cursor look | 
|  | 8 | like a non-blinking red block, make it inverse background of the character it's | 
|  | 9 | over or to highlight that character and still choose whether the original | 
|  | 10 | hardware cursor should remain visible or not.  There may be other things I have | 
|  | 11 | never thought of. | 
|  | 12 |  | 
|  | 13 | The cursor appearance is controlled by a "<ESC>[?1;2;3c" escape sequence | 
|  | 14 | where 1, 2 and 3 are parameters described below. If you omit any of them, | 
|  | 15 | they will default to zeroes. | 
|  | 16 |  | 
|  | 17 | Parameter 1 specifies cursor size (0=default, 1=invisible, 2=underline, ..., | 
|  | 18 | 8=full block) + 16 if you want the software cursor to be applied + 32 if you | 
|  | 19 | want to always change the background color + 64 if you dislike having the | 
|  | 20 | background the same as the foreground.  Highlights are ignored for the last two | 
|  | 21 | flags. | 
|  | 22 |  | 
|  | 23 | The second parameter selects character attribute bits you want to change | 
|  | 24 | (by simply XORing them with the value of this parameter). On standard VGA, | 
|  | 25 | the high four bits specify background and the low four the foreground. In both | 
|  | 26 | groups, low three bits set color (as in normal color codes used by the console) | 
|  | 27 | and the most significant one turns on highlight (or sometimes blinking--it | 
|  | 28 | depends on the configuration of your VGA). | 
|  | 29 |  | 
|  | 30 | The third parameter consists of character attribute bits you want to set. | 
|  | 31 | Bit setting takes place before bit toggling, so you can simply clear a bit by | 
|  | 32 | including it in both the set mask and the toggle mask. | 
|  | 33 |  | 
|  | 34 | Examples: | 
|  | 35 | ========= | 
|  | 36 |  | 
|  | 37 | To get normal blinking underline, use: echo -e '\033[?2c' | 
|  | 38 | To get blinking block, use:            echo -e '\033[?6c' | 
|  | 39 | To get red non-blinking block, use:    echo -e '\033[?17;0;64c' |