No HDMI output when booting from USB drive on rPi W2

[atomant]

Hello good people of TCL community!

My setup: Raspberry Pi Zero W2 running piCore 15.0.0 (downloaded it today from the official download link)

Here's the deal: I have the same exact system burned onto a MicroSD card and also onto an SSD drive. I set up the rPi to be able to boot from USB (program_usb_boot_mode=1 into config.txt and then booted from SD card).
When booting from SD card I get video output on the HDMI port, albeit a bit unstable as it flashes/disappears/blinks randomly but constantly for short times but I suppose that could be remedied by playing around with the corresponding "fields" in config.txt like config_hdmi_boost, hdmi_safe, etc...
My problem is that if i boot from the USB SSD drive I get no video output at all, screen stays blank. I'm quite sure it actually boots based on the rPi's and USB drive's LEDs and If i connect a keyboard and blindly type in "sudo poweroff now" it turns off (LEDs turn off) suggesting that it managed to boot to a prompt and was accepting input.
What I tried so far and observed no change in behavior:
-using a powered USB hub to connect the drive
-connecting the drive directly (so no USB hub)
-trying 3 different HDMI cables
-trying another HDMI/mini HDMI adapter
-trying 3 different power sources (all should have been more than enough to supply enough power)
-trying 3 different monitors
-trying to play around with the HDMI related settings in config.txt (safe mode, no safe mode, overscan, no overscan, trying hdmi_group and hdmi_mode, hdmi_force_hotplug...)
-trying "dtoverlay=vc4-kms-v3d" and "dtoverlay=vc4-fmsf-v3d" (i changed these everywhere I found them in the file)
-adding boot_delay=5 (was suggested somewhere online to give more time for hardware components to get up to speed or whatnot)

I have no idea what else to try, I don't get why there's video with SD card but no video with USB drive.
Any suggestions, ideas?

[atomant]

Correction, "dtoverlay=vc4-fkms-v3d" not "dtoverlay=vc4-fmsf-v3d" above...

[Rich]

Hi atomant
Maybe you need to add something like:

Code: [Select]

waitusb=5to your cmdline.txt file?

[Paul_123]

There should be nothing needed for a HDMI signal showing the console.   Plain HDMI cable/monitor works for me.


If you want graphics (i.e. vc4 overlays)  Then you need to load the graphics kernel modules  (graphics-KERNEL.tcz)

[mocore]

Hello good people of TCL community!

My setup: Raspberry Pi Zero W2
...
When booting from SD card I get video output on the HDMI port, albeit a bit unstable as it flashes/disappears/blinks randomly but constantly for short times but I suppose that could be remedied by playing around with the corresponding "fields" in config.txt like config_hdmi_boost, hdmi_safe, etc...

what spec PSU?

things to try

- power supply with *more* amps !!

- different usb (could be faulty?)

- "official" raspberry OS image (sd & usb) , if you sill have
   "randomly - unstable : flashes/disappears/blinks " hdmi
   ... it will no doubt be of interest to hw manufactures / might be firmware/hw fault?
   ( if more amps/PSU/ ect fails to resolve issues )

*imho!

[atomant]

There should be nothing needed for a HDMI signal showing the console.   Plain HDMI cable/monitor works for me.


If you want graphics (i.e. vc4 overlays)  Then you need to load the graphics kernel modules  (graphics-KERNEL.tcz)

Console is fine, i don't need a graphics environment.

[atomant]

Hi atomant
Maybe you need to add something like:

Code: [Select]

waitusb=5to your cmdline.txt file?

Hi Rich 

Good suggestion, I tried it but no effect. 

[atomant]

what spec PSU?

All are 5V (obviously), one is 2.4A max, the second is 4A max, the third is 3.1A max (tho this latter one i suspect is on paper as it's some no name Chinese cheapo charger).

things to try

- power supply with *more* amps !!

I tried one with max 6A output, no change. This also gave me the opportunity to measure currents and with the USB hub connected without external power it never went above 0.6A, with the HUB powered it never went above 0.3A, so I'd say it's not the power that's the problem here.

- different usb (could be faulty?)

You mean the hub? As i said, tried without the hub, no change, and i tested the hub on my computer, connected things, worked flawlesly, doesn't seem to be the culprit.

- "official" raspberry OS image (sd & usb) , if you sill have
   "randomly - unstable : flashes/disappears/blinks " hdmi
   ... it will no doubt be of interest to hw manufactures / might be firmware/hw fault?
   ( if more amps/PSU/ ect fails to resolve issues )

I'll try this later.

Thank you for your thoughts.

[mocore]

You mean the hub? As i said,
...
Thank you for your thoughts.

tbh i just scanned you post for any mention of *PSU amps
and after not spotting anything obvious

just threw my *generic* faulty-pi advice out there
(mostly gleaned on reading the pi forum's since ( i guess pre)2011 )

there where some interesting historical threads on implementing usb
.. most interesting bits where (imho) in relation to working around
hw that dose not follow the spec

if you ruled out power , my (non "pro")  guess would be fw/hw issue
especially if you allready tried alternative hw (monitor/psu) ect

[core-user]

Many people have problems trying to power RPi with phone chargers, they don't supply a constant voltage, buy an official PSU....

[atomant]

Many people have problems trying to power RPi with phone chargers, they don't supply a constant voltage, buy an official PSU....

Currently it's running off an... um... powerbrick? Not sure what these are called, definitely not a phone charger.

[atomant]

Here's some new information, I remembered I have an old rPi lying around (from the original series, so not a 2) and I gave it a try and it's the exact same thing, i get video from SD card and no video from USB drive. But seems to boot otherwise, can blindly do the poweroff and it will react. This must either be a configuration problem or a hardware problem with the SSD or the USB dongle thing I have it in. The dongle and SSD seem to work if i connect them to my computer, sadly I don't have any other SSDs/dongles lying around to test if they make a difference. But I sorta lean towards this being a configuration problem, maybe I'm not setting something I should. Or setting something I shouldn't.

[atomant]

I tried writing a system onto a pendrive and boot from that with and without the USB hub, again, same result. I'm puzzled...it must be some-sort of configuration issue.

Isn't there anything I need to change in config.txt or cmdline.txt to boot from an USB drive?

[mocore]

I'm puzzled...it must be some-sort of configuration issue.

try *their* default

- "official" raspberry OS image
   ( if more amps/PSU/ ect fails to resolve issues )

I'll try this later.

... 

(AFAIK) if you want "official" support using their os+config is the only easiest way to get it

perhaps your hw setup + config it to esoteric
to have got'en much testing

[Rich]

Hi atomant
It's a bit of a long shot, but if you have a keyboard plugged
in while booting from your USB device, does that change
anything?