HenriZ
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NOOBS:Can't access tty; job control turned off

Mon Feb 29, 2016 3:42 pm

A strange thing I'm having with the NOOBS install. Hardware: stock Raspberry Pi 2B+. 1x Kingston 16Gb, 2x Philips 16Gb, 1x noname 16Gb, all class 10 SHCD's, all purchased new for this purpose and not used for other stuff.

Now the first time I booted my Pi, I followed the NOOBS instructions. Just a plain empty card, unzip the NOOBS zipfile to it, boot. Worked like a charm. Once. Never more.

Now whatever I do, I can't reproduce that. The second I try, I get a boot with 'Can't access tty; job control turned off'.

However, if I pick any of these cards and use ie. dd or win32diskimager to write the Raspbian .img file to it, it works fine. I can boot, expand the FS, and be done with it.

So it's not a critical problem, but it does make me wonder what's going wrong. I have tried formatting the cards under windows, I have tried removing partitions, creating and formatting a new partition (all using fdisk), but to no avail. Same thing under linux, format, quick, slow, write all zero's, fat16, fat32, LBA or not, it does not matter, it does not work.

Anyone have a clue as to why?

Ofcourse I have googled this issue, some ppl solve it by ading a avoid_safe_boot=1 to the config.txt, which noobs doesn't have, or at least, not in the standard way. Also this seems to be to avoid powersupply-issues, which I don't have. I'm trying this on an empty board, have a 3A USB power supply, and a good quality USB cable. With the Raspbian .img I can boot this setup with 2 LCD's, the HDMI port connected, a WIFI dongle and USB mouse/keyboard, without issues. Using NOOBS without any added hardware it does not boot. So it's not a power issuel. (also no colored squares).

I started out with the no-name SD card (which worked with NOOBS the first time, never after) but also bought a (genuine) Kingston and a (genuine) Philips Micro SD (SHCD, class 10). All have the same behaviour.

To clarify; the raspberry does boot somewhat, as I do get a screen stating Can't access tty; job control turned off.

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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 01, 2016 2:18 am

Hm, hard to diagnose without being able to reproduce it. If you're willing to send the card exhibiting this behaviour in for us to take a look, please PM me.

HenriZ
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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 01, 2016 10:16 pm

All cards do this. That's the point. I also thought it was the card causing it, so I bought some new ones. They also do this. So it's not in the card, it's something in my Pi.

It's also not related to connected hardware, as it also does this when nothing is connected. Lastly it's not related to the power supply, as it is sufficient.

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rpdom
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 02, 2016 7:25 am

HenriZ wrote:To clarify; the raspberry does boot somewhat, as I do get a screen stating Can't access tty; job control turned off.
That message is probably just a result of the problem, not the actual problem itself. There is most likely some messages a few lines before that which may give some clue as to what the real issue is.

Is it possible to upload a picture of the screen when it halts? You may need to put it on imgur or something as the allowed forum file size is a bit small for such things.

HenriZ
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 02, 2016 9:40 am

There is no other message. The screen is black with only this message at the top. Nothing more.

novice365
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Re: NOOBS:Can't access tty; job control turned off

Sat Mar 05, 2016 5:18 pm

I have the same problem. My Pi (model B+ V1.2) running NOOBS was working well for months and I was trying to program an LED to light up every time a twitter hashtag is used. I put the job aside and forgot about it for awhile leaving the LED connected on pins 9 and 7 with the Pi on for several days. Upon returning to the project, the Pi was working still (as it was still on from when I left it several days earlier), however, my previously working LED program was not lighting the LED anymore. Thinking a reboot might help, I restarted my Pi and got the rainbow color screen followed immediately by a pan black screen with only:

sh: can't access tty; job control turned off
/#

I can type ls command and I get:

bin boot dev etc home init keymaps lib lib32 libexec linuxrc media mnt mnt2 opt proc root run sbin settings sys tmp us r var
/#

I can cd to boot and get:

/boot #

but then ls command returns nothing. (I was thinking I could somehow modify boot as the OP mentioned, as I also found modifying boot to have avoid_safe_boot=1 within it somewhere). I also read something about overclocking potentially causing this but I don't know what that is. Any advice would be greatly appreciated.

HenriZ
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Re: NOOBS:Can't access tty; job control turned off

Sat Mar 05, 2016 6:10 pm

In my case, no overclock was ever applied to my Raspberry, and with the same SD cards and powersupply it starts fine if I write the raspbian .img to the disk using dd or win32diskimager.

However, as soon as I insert ANY (new, old, does not matter) normal formatted SD card with the NOOBS install on it, I get this screen.

Also noteworthy this screen appears VERY fast. So it hasn't done much before getting there.

If I take a non-working SD, write the raspbian image to it using DD, then boot, it works fine. Now if I take that card and use linus to format it to FAT32, unzip the NOOBS file on it, it gives this error.

Pi is otherwise working fine.

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procount
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Re: NOOBS:Can't access tty; job control turned off

Sat Mar 05, 2016 10:30 pm

After getting this message, try posting the output of 'dmesg'.
Also what is the output of 'cat /tmp/debug'?
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

HenriZ
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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 08, 2016 2:33 pm

First a normal boot. Done from a raspbian .img written to the SDcard using dd and later installed and expanded to 16Gb. This to show that my pi and my power supply are not the issue:
https://www.youtube.com/watch?v=mKTWIrN7Des

Second, a failed boot from the same 16Gb SD card, formatted to normal FAT (using a normal windows laptop):
https://www.youtube.com/watch?v=PeLiFY8IbnM

The dmesg and cat /tmp/dbg output.. looks like a normal boot, until it halts. /tmp/debug does not exist.

https://www.youtube.com/watch?v=4BtCxtzrX64

A few seconds into that movie I rotate the cam, I have edited the video on youtube to also rotate, so you can read what it says. If you can't (except for the first 15s), then youtube is not finished yet.

Apologies for my kids and wife on the background, if anyone can explaim me how to turn those of when making video's, i would really like to know :P

Note that the last part of the dmesg output concerns my wireless device and is of no consequence, If I unplug the USB device, it doesnt give this ('regulartory domain... etc) but still does not boot.

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procount
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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 08, 2016 3:04 pm

Try adding 'disablesafemode' to the end of recovery.cmdline on the NOOBS FAT partition. (without the ' ' of course).

It looks like NOOBS is bombing out to the rescue shell because you have some connections to a GPIO pin that is used (intentionally) to access this mode.
The 'disablesafemode' command should prevent this from happening.
See https://github.com/raspberrypi/noobs#ho ... -safe-mode
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

HenriZ
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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 08, 2016 8:48 pm

In my start post:
avoid_safe_boot=1
This flag does not change anything. Even when there's nothing connected to the board, it does this.

Also note that stock Raspbian boots fine. NOOBS does not.

Don't get me wrong, I totally appreciate your help and time!

I'll try the cmdline setting of this option, however, even if this works, then this is stil inconsistent behaviour, because why would a stock raspbian (without disabling the safe mode) work fine, but NOOBS not? I'm trying to figure out the root cause.

Which might very well be a hardware defect, I'm certainly not ruling this out. The 'normal' i2c bus on this board has one broken pin (CLK). This always stays 'low'.

What boggles me is not so much the fact that it does this, but that it does this on NOOBS but not on Raspbian.

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rpdom
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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 08, 2016 8:56 pm

HenriZ wrote:In my start post:
avoid_safe_boot=1
This flag does not change anything. Even when there's nothing connected to the board, it does this.
I'm not surprised. I've never heard of that option.

Perhaps you meant

Code: Select all

avoid_safe_mode=1
?

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procount
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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 08, 2016 9:17 pm

Noobs and raspbian are not the same thing and they use different options. It is easy to get them confused.
Use the right option for the right program and you might find it works.

The disablesafemode option is checked in the init script of Noobs which is totally different to Raspbian and is definitely required. Maybe the other option is required for the kernel or gpu boot code...?
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

HenriZ
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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 08, 2016 9:23 pm

I'm not confused. NOOBS and raspbian are basically the same thing. The difference i amongst other things, is, raspbian uses the /boot/config.txt file, in which you can specify the avoid_safe_boot option. NOOBS does not. However, adding the disablesafemode does exactly the same thing. Where to apply the option is different for Noobs and Raspbian, but it's still the same option. So wether or not that option has to be set, should be the same for both. If you HAVE to set it for NOOBS, you also HAVE to set it for Raspbian, and vice versa. However, Raspbian boots fine without the opton. What i mean they're the same thing, basically both are the same linux kernel loading. I hope you understand I really appreciate you trying to help us, by no means I mean to discourage you.

I haven't been able to test it yet. But even if it works, this is not true:
Use the right option for the right program and you might find it works.
In both cases we're talking about disabling the safe mode boot. The safe mode boot (if it even still exists, i read somewhere it's deprecated) is basically a pin on the GPIO you can connect, forcing it to safe boot.

The behaviour should be the same for NOOBS as Raspbian, as we're talking about the same option.

So what boggles me then, is why would I have to set this option for NOOBS, but not for Raspbian. That does not add up.

(and yes, I did mean disable_safe_mode=1.. I'm a somewhat chaotic person)

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procount
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Re: NOOBS:Can't access tty; job control turned off

Tue Mar 08, 2016 10:02 pm

OK, but your assumption that they are "basically the same thing" is not correct.
Noobs is a very simple buildroot kernel that executes a very small init script to run the noobs recovery program.
Here are the offending lines of init that are causing your NOOBS to go to the shell because of the attachments to your GPIO pins.

Code: Select all

 SAFE_MODE=`vcgencmd get_config safe_mode_gpio`
 if ( [ ${SAFE_MODE#*=} -eq 1 ] && ! grep -q disablesafemode /proc/cmdline ) || grep -q rescueshell /proc/cmdline; then
     sh
 else
     ....
(The error message about Job Control comes from the shell, I suspect because init has not set something up properly, but it's not really important)

The same happened to me when I put a GERT VGA666 on my Pi and I had to mod my version of NOOBS (PINN) to get it to work properly.

To be clear, disablesafemode is a single word (no underscores, no '=1') to be added to the end of the single line in recovery.cmdline (not config.txt).
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

peterpan123123
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 6:38 am

I have the exact same problem.
Worked for weeks with connected pins on GPIO, suddenly stopped working and showed "can't access tty; job control turned off".

Unplugged all connection (USB, GPIO) --> still the same.
Tried installing via NOOBS with different SD cards (different brands) and different power supply --> still the same.

It works with disablesafemode, but then the reconnected GPIO won't work anymore.

Have a Raspberry Pi 2.

HenriZ
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 8:53 am

procount wrote:OK, but your assumption that they are "basically the same thing" is not correct.
It's not an assumption, it's fact. It's just a matter of perspective, generalistic or detaillistic. We're both right.
Noobs is a very simple buildroot kernel that executes a very small init script to run the noobs recovery program.
Here are the offending lines of init that are causing your NOOBS to go to the shell because of the attachments to your GPIO pins.
Again, there is nothing connected to any pin. Sure, on my video's there was, but as my postings also say, even if I disconnect, it does the same.

I have tried adding the option to the cmdline, to no avail. So it's not going into safe mode..
To be clear, disablesafemode is a single word (no underscores, no '=1') to be added to the end of the single line in recovery.cmdline (not config.txt).
Yep, I understood, does not change a thing, unfortunatelly.

It's no biggie, as the pi works fine with a raspbian SD card, still I would like to find out why it's doing this.

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procount
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 9:46 am

@peterpan123123 - Glad disablesafemode worked for you. This indicates the GPIO pin for noobs safemode is not in its default state, even after disconnecting everything. But disablesafemode shouldn't affect the use of the GPIO pin thereafter. Have you tried it with plain Raspbian without NOOBS? If your connected GPIO still does not work, I would give your GPIO pins a thorough work out to check you haven't damaged any of them. If they work ok, then check your software to check it has not been corrupted. - Just some ideas for you.......
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

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procount
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 2:36 pm

avoid_safe_mode was removed from Raspbian a long time ago.

Edit: Actually on 18th March 2014. See http://elinux.org/RPI_safe_mode
Last edited by procount on Wed Mar 09, 2016 2:56 pm, edited 1 time in total.
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

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procount
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 2:51 pm

PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

peterpan123123
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 4:51 pm

procount wrote:@peterpan123123 - Glad disablesafemode worked for you. This indicates the GPIO pin for noobs safemode is not in its default state, even after disconnecting everything. But disablesafemode shouldn't affect the use of the GPIO pin thereafter. Have you tried it with plain Raspbian without NOOBS? If your connected GPIO still does not work, I would give your GPIO pins a thorough work out to check you haven't damaged any of them. If they work ok, then check your software to check it has not been corrupted. - Just some ideas for you.......
I tried some OS which come with images. All work fine. But despite of NOOBS my original Recalbox Image doesn't work anymore, meaning it stays at the exactly same message "Can't access tty; job control turned off" even if I disconnect all GPIO. I can boot with "disablesafemode", but with connected GPIO they don't work anymore. I already checked the GPIO for damage and checked all cables for shorts or other things and could not find any problems.

How can I give my GPIO pins a work out to check for damages?

Btw. a clean install with recalbox is not possible, because it only works with NOOBS.

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procount
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 5:04 pm

Sorry but you have reached the limit of my knowledge.
As recalbox is a fork of noobs, maybe you should raise an issue with the author of that to see if he can solve your problem...
https://github.com/recalbox/recalbox-rescue/issues
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

peterpan123123
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 6:38 pm

I already tried that - no solution.

I did send it back to the seller. Maybe it is defective.

HenriZ
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 7:13 pm

procount wrote:avoid_safe_mode was removed from Raspbian a long time ago.

Edit: Actually on 18th March 2014. See http://elinux.org/RPI_safe_mode
Yes, It's deprecated, as I already said.

It must be a hardware defect that causes this, I can come to no other conclusion. And I do have a hardware defect on my pi, with it's i2c port being fried. Other than that, it functions fine.

The thing that amazes me, is that this problem does surface when booting from a NOOBS SD, but not from a Raspbian image. In the real world, it poses no problem, since it will always be booting from the Raspbian SD, is embedded, and works fine. It's still puzzeling tho.

peterpan123123
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Re: NOOBS:Can't access tty; job control turned off

Wed Mar 09, 2016 7:32 pm

I am maybe wrong, but I had the feeling, that the temperature of the cpu is higher. I never measured it before, but it just felt quite hot, when I touched it with my finger - even if it hangs at "can't access tty..." (and isn't really busy at that state).

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