Generate EDID binary dumps by reading an Xorg log file. The log file must contain a hex EDID dump, this is achieved by enabling ModeDebug in the Monitor section:
Section "Monitor"
...
Option "ModeDebug" "TRUE"
EndSection
Example usage:
% ./edid-extract /var/log/Xorg.0.log
Found EDID for Samsung SMBX2240
EDID dump written to DFP-0
Found EDID for Samsung SMBX2240
EDID dump written to DFP-1
% ls DFP-*
DFP-0 DFP-1
% hexdump -C DFP-0
00000000 00 ff ff ff ff ff ff 00 4c 2d 84 06 32 32 42 43 |........L-..22BC|
00000010 0e 15 01 03 80 30 1b 78 2a 78 f1 a6 55 48 9b 26 |.....0.x*x..UH.&|
00000020 12 50 54 bf ef 80 71 4f 81 00 81 40 81 80 95 00 |.PT...qO...@....|
00000030 b3 00 a9 40 95 0f 02 3a 80 18 71 38 2d 40 58 2c |...@...:..q8-@X,|
00000040 45 00 dd 0c 11 00 00 1e 00 00 00 fd 00 32 4b 1e |E............2K.|
00000050 51 11 00 0a 20 20 20 20 20 20 00 00 00 fc 00 53 |Q... .....S|
00000060 4d 42 58 32 32 34 30 0a 20 20 20 20 00 00 00 ff |MBX2240. ....|
00000070 00 48 39 58 42 34 30 31 30 32 34 0a 20 20 01 b6 |.H9XB401024. ..|
00000080 02 01 04 00 02 3a 80 d0 72 38 2d 40 10 2c 45 80 |.....:..r8-@.,E.|
00000090 dd 0c 11 00 00 1e 01 1d 00 72 51 d0 1e 20 6e 28 |.........rQ.. n(|
000000a0 55 00 dd 0c 11 00 00 1e 01 1d 00 bc 52 d0 1e 20 |U...........R.. |
000000b0 b8 28 55 40 15 1e 11 00 00 1e 8c 0a d0 90 20 40 |.(U@.......... @|
000000c0 31 20 0c 40 55 00 dd 1e 11 00 00 18 8c 0a d0 8a |1 .@U...........|
000000d0 20 e0 2d 10 10 3e 96 00 dd 1e 11 00 00 18 00 00 | .-..>..........|
000000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 99 |................|
00000100