Display file format

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DISPLAY and function-key help files are text files in either DOS or UNIX format (i.e. with or without <CR>).
See also IsoLinux Mate to help with writing DISPLAY files under Windows (or under WINE).

In addition, the following special codes are interpreted:

Clear the screen and home the cursor

 <FF>                                     <FF> = <Ctrl-L> = ASCII 12  

Note that the screen is filled with the current display color.

Specify background and foreground colors

 <SI><bg><fg>                             <SI> = <Ctrl-O> = ASCII 15  

Set the display colors to the specified background and foreground colors, where <bg> and <fg> are the 2 hex digits representing 1 byte, corresponding to the standard PC display attributes:

  0 = black       	8 = dark grey
  1 = dark blue   	9 = bright blue
  2 = dark green  	a = bright green
  3 = dark cyan   	b = bright cyan
  4 = dark red    	c = bright red
  5 = dark purple 	d = bright purple
  6 = brown       	e = yellow
  7 = light grey  	f = white

Picking a bright color (8-f) for the background, results in the corresponding dark color (0-7), with the foreground flashing.

Colors are not visible over the serial console.

See also Examples/message file.

Display graphic from filename

 <CAN>filename<newline>                  <CAN> = <Ctrl-X> = ASCII 24  

If a VGA display is present, enter graphics mode and display the graphic included in the specified file. The file format is an ad hoc format called LSS16. The included Perl program, "ppmtolss16", can be used to produce these images. This Perl program also includes the file format specification.

The image is displayed in 640x480, 16-color mode. Once in graphics mode, the display attributes (set by <SI> code sequences) work slightly differently: the background color is ignored, and the foreground colors are the 16 colors specified in the image file. For that reason, ppmtolss16 allows you to specify that certain colors should be assigned to specific color indices.

Color indices 0 and 7 in particular, should be chosen with care: 0 is the background color, and 7 is the color used for the text printed by Syslinux itself.


See also info about mtPaint to help with LSS16 background images.

Return to text mode

 <EM>                                     <EM> = <Ctrl-Y> = ASCII 25  

If we are currently in graphics mode, return to text mode.

Output printing modes

 <DLE>..<ETB>                       <Ctrl-P>..<Ctrl-W> = ASCII 16-23  

These codes can be used to select in which modes to print a certain part of the message file. Each of these control characters selects a specific set of modes (text screen, graphics screen, serial port) for which the output is actually displayed:

  Character                   	Text	Graph	Serial
  ------------------------------------------------------
  <DLE> = <Ctrl-P> = ASCII 16 	No  	No   	No
  <DC1> = <Ctrl-Q> = ASCII 17 	Yes 	No   	No
  <DC2> = <Ctrl-R> = ASCII 18 	No  	Yes  	No
  <DC3> = <Ctrl-S> = ASCII 19 	Yes 	Yes  	No
  <DC4> = <Ctrl-T> = ASCII 20 	No  	No   	Yes
  <NAK> = <Ctrl-U> = ASCII 21 	Yes 	No   	Yes
  <SYN> = <Ctrl-V> = ASCII 22 	No  	Yes  	Yes
  <ETB> = <Ctrl-W> = ASCII 23 	Yes 	Yes  	Yes

For example, the following will actually print out which mode the console is in:

  <DC1>Text mode<DC2>Graphics mode<DC4>Serial port<ETB>

End of file

 <SUB>                                   <SUB> = <Ctrl-Z> = ASCII 26  

End of file (DOS convention).

Beep

 <BEL>                                    <BEL> = <Ctrl-G> = ASCII 7  

Beep the speaker.

See also

  • mtPaint can create/edit/convert/save lss16 graphic files to be used as background images in DISPLAY help message boot screens. Hint: use (or convert to) "Indexed" 16 colors palette, then save as .lss.
  • IsoLinux Mate can help with writing DISPLAY files under Windows (or under WINE).