From 591f20ba8db93e6d65fb1f3abe4da1c65e6b6d67 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Sat, 26 Jul 2003 20:17:13 +0000 Subject: [PATCH] Document the decode-edid.pl script. git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@1907 7894878c-1315-0410-8ee3-d5d059ff63e0 --- doc/chips/eeprom | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/doc/chips/eeprom b/doc/chips/eeprom index 2f64fb45..fbbcc5a4 100644 --- a/doc/chips/eeprom +++ b/doc/chips/eeprom @@ -164,3 +164,39 @@ Notes: The script assumes that Perl can be found at /usr/bin/perl. If different, you will need to adjust the first line of the file accordingly, or else you will get a strange "decode-vaio.pl: no such file or directory" error. + + +Decode-edid.pl + +This Perl script acts as an interface between the eeprom module and +parse-edid, which is part of read-edid. Read-edid is a tool for gathering +information on VESA PNP monitors. It is somewhat similar to what our +ddcmon driver does, except that ddcmon outputs user-oriented data while +read-edid generates a a computer oriented configuration file (primarily +for XFree86). + +Read-edid is made of two components, get-edid which retrieves binary data +from the monitor, and parse-edid which decodes the data into useful +information. Get-edid uses low level functions, and relies on compliance +of both the video card and the monitor to some standard (DCC as it is +called). It may not work for everyone. On the other hand, some video +cards make this information available on an I2C bus and we are able to +get it using our eeprom module. That's why we wrote this script that +converts the data as exported by our eeprom module into what parse-edid +expects from get-edid. That way, users who can't get get-edid to work +still have a chance to be able to retrieve the wanted information thanks +to the lm_sensors modules and tools. + +Use: + +Unload the ddcmon if it was loaded, load the eeprom module instead. Then, +run the script. The script will try to figure out on which I2C bus and at +which address is the eeprom, but it may fail. In this case, you can pass +the parameters to the script. Examples: + + decode-edid.pl 1 + decode-edid.pl 2 0x50 + +You will find additional details in the script itself. Read-edid is avilable +there: + http://john.fremlin.de/programs/linux/read-edid/