How to get edid on L4T Cboot phase

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

how to get edid on L4T Cboot phase? which I2C used to get edid? we see log follow, we want to know how to get it?
0002.333] edid read success
[0002.348] edid read success[0002.354] DT entry for leds-pwm not found

[0002.358] width = 3840, height = 1080, frequency = 297000000
[0002.364] width = 2560, height = 720, frequency = 148500000
[0002.369] width = 2048, height = 768, frequency = 130000000
[0002.375] width = 2560, height = 1440, frequency = 119000000
[0002.380] width = 2880, height = 2160, frequency = 199750000
[0002.386] width = 1366, height = 768, frequency = 85500000
[0002.391] width = 2732, height = 768, frequency = 170000000
[0002.397] width = 2880, height = 900, frequency = 213000000
[0002.403] width = 1280, height = 720, frequency = 74175824
[0002.408] width = 1280, height = 720, frequency = 74175824
[0002.414] width = 1920, height = 1080, frequency = 74175824
[0002.419] width = 1920, height = 1080, frequency = 148351648
[0002.425] Best mode Width = 1920, Height = 1080, freq = 148351648

2

t210 cboot is not open source. I don’t think you are able make any change to cboot.

3

we add bridge for HDMI to two hdmi ports,we need to display logo on u-boot phase,so we need get the edid timing for the bridge.

4

The default logo is from cboot, not uboot and we don’t enable boot logo in uboot.

The i2c bus is same in kernel and cboot. If you want to know which i2c bus is in use, you can check in in kernel side.

5

Because we add bridge, we need config the driver on u-boot, so we need know the edid timing, and we see cboot get the edid, does it get the edid by I2C from the monitor? From the log, we see the best edid timing from cboot sometimes not the right best tming.
See follow log：
[0003.120] width = 2560, height = 720, frequency = 148500000
[0003.126] width = 0, height = 0, frequency = 0
[0003.130] width = 0, height = 0, frequency = 0
[0003.135] width = 0, height = 0, frequency = 0
[0003.139] width = 0, height = 0, frequency = 0
[0003.143] width = 0, height = 0, frequency = 0
[0003.148] Best mode Width = 640, Height = 480, freq = 25174825

6

Yes, cboot gets the timing from the monitor through i2c.

7

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