kingkevin
/
board
1
0
Fork 0
Code Issues Pull Requests Projects Releases 37 Wiki Activity

doc: move limitions higher

This commit is contained in:
King Kévin 2022-06-22 14:27:49 +02:00
parent 3d6d42d1d8
commit 432de7d2c8
1 changed files with 15 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
README.md
View File

@ -43,6 +43,21 @@ By default, the 5V supplied by the device is forwarded to the monitor.
To further reduce the attack surface, you can disable this by cutting the trace between the two pads marked 5V.
The risk is that some monitors rely on this signal to detect when a device is plugged in.
limitations
===========
High-bandwidth Digital Content Protection (HDCP) is not supported since the DDC interface is limited to the EDID information.
mode of operation
=================
To protect the monitor, the HDMI firewall only forwards the signal lines used for audio/video (A/V) data transfer (D0, D1, D2, CK).
All other signal lines are unconnected (CEC, SDA, SCL, utility/HEAC+, HPD).
This will block all non A/V interfaces (e.g. DDC, HPD, CEC, HEAC, MHL)
The SDA/SCL lines used for the DDC interface to provide the EDID information to the device are connected to an EEPROM on the firewall.
This is where you need to copy the monitor information to.
This limits the DDC interface to the EDID information.
installation
============
@ -331,18 +346,3 @@ To verify of the data has been written correctly, read it back:
~~~
sudo ./edid-rw 4 | edid-decode
~~~
limitations
===========
High-bandwidth Digital Content Protection (HDCP) is not supported since the DDC interface is limited to the EDID information.
mode of operation
=================
To protect the monitor, the HDMI firewall only forwards the signal lines used for audio/video (A/V) data transfer (D0, D1, D2, CK).
All other signal lines are unconnected (CEC, SDA, SCL, utility/HEAC+, HPD).
This will block all non A/V interfaces (e.g. DDC, HPD, CEC, HEAC, MHL)
The SDA/SCL lines used for the DDC interface to provide the EDID information to the device are connected to an EEPROM on the firewall.
This is where you need to copy the monitor information to.
This limits the DDC interface to the EDID information.