[SOLVED] SARPI (fatdog) on RPi4

arfon · 01-22-2020, 07:14 AM

When I booted the RPi4 from the newly "xc"'d sdcard there was no HDMI video. The fix was to uncomment the following two lines in config.txt (in the mmcblk0p1 partition):

Code:

 # Uncomment if you get no picture on HDMI for a default "safe" mode
hdmi_safe=1

# Uncomment if hdmi display is not detected and composite is being output
hdmi_force_hotplug=1

After installing SARPI and rebooting, again, no HDMI video... Again, the fix was to uncomment the same two lines in /boot/config.txt

Exaga · 01-22-2020, 03:38 PM

Quote:

Originally Posted by arfon

When I booted the RPi4 from the newly "xc"'d sdcard there was no HDMI video. The fix was to uncomment the following two lines in config.txt (in the mmcblk0p1 partition):

Code:

 # Uncomment if you get no picture on HDMI for a default "safe" mode
hdmi_safe=1

# Uncomment if hdmi display is not detected and composite is being output
hdmi_force_hotplug=1

After installing SARPI and rebooting, again, no HDMI video... Again, the fix was to uncomment the same two lines in /boot/config.txt

OK cool. Thanks for this. I will certainly bear it in mind and if any other Slackers have the same experience as you then it'll become an issue to address. I've not had any problems of the kind you've described with Slackware ARM current on the RPi4. In fact, much the opposite.

TheTKS · 01-22-2020, 09:59 PM

Quote:

Originally Posted by Exaga

OK cool. Thanks for this. I will certainly bear it in mind and if any other Slackers have the same experience as you then it'll become an issue to address. I've not had any problems of the kind you've described with Slackware ARM current on the RPi4. In fact, much the opposite.

No problems here with HDMI video. Haven’t tried audio.

arfon · 03-16-2020, 02:17 AM

I found out WHY the HDMI video doesn't work on some installs....

If you use an OLD monitor (or a TV) for the install, they may not be able to handle the high default resolution of the RPi4. When this is the case, the monitor just shows a black or a "no input signal" screen.

You can fix this by changing monitors -OR- changing the config file as I described in the first post.

Exaga · 03-17-2020, 01:47 AM

Quote:

Originally Posted by arfon

I found out WHY the HDMI video doesn't work on some installs....

If you use an OLD monitor (or a TV) for the install, they may not be able to handle the high default resolution of the RPi4. When this is the case, the monitor just shows a black or a "no input signal" screen.

You can fix this by changing monitors -OR- changing the config file as I described in the first post.

Sure thing. This happens when the video mode of the screen display cannot match the video mode that the RPi is using. It's a known quantity and can usually be fixed by altering one's /boot/config.txt settings to operate on a lower/lesser level. Part of the fun in getting things to work in Slackware ARM is solving issues such as these. Although, this is not a Slackware ARM [or SARPi] issue. It's all down to the capabilities of the screen display that you're using.

I generally try to connect via ssh when there's no expected display, and if that is working OK I then look at the video mode(s), then cables, etc.