i.MX ProcessorsのトピックRe: /sys folder empty after deploying the image on the SD card

/sys folder empty after deploying the image on the SD card

lordtheo — Fri, 03 Feb 2017 15:43:29 GMT

Hi Everyone

Please Help!!!

I am using imx6ulevk for my embedded application.

After I deployed the whole image on the sd card with the following command

$ sudo dd if=build/tmp/deploy/images/imx6ulevk/fsl-image-qt5-imx6ulevk.sdcard of=/dev/<sdcard dev>

i figured out that my /sys folder inside the SD is empty. Nothing inside, 0 bytes.

I can boot the Linux on imx6ulevk board but I cannot stop the LCD for turning blank after 5min

because "$ echo 0 > /sys/class/graphics/fb0/blank" and others similar commands will not work since /sys folder is empty.

when " $ du -hs /sys" returns 0 bytes and " $ vi sys/class/graphics/fb0/blank" returns "cannot read the file"

I tried everything below to disable the blanking but without succes:

echo -e '\033[9]' > /dev/tty0

echo -e '\033[9;0]' > /dev/tty1

echo 0 > /sys/class/graphics/fb0/blank

echo 0 > /sys/class/graphics/fb1/blank

passing consoleblank=0 to bootargs

modifying drivers/tty/vt/vt.c with static int blankinterval = 0;

Disabling CONFIG_VT_CONSOLE

setterm -blank 0

Any help will be welcome.

Best Regards,

Theo.

Re: /sys folder empty after deploying the image on the SD card

BiyongSUN — Mon, 06 Feb 2017 02:59:25 GMT

You can download the binary release to try

For avoid the auto blank, you can give the kernel parameters consoleblank=0 by uboot boot args, which is in the Linux source tree document Documentation\kernel-parameters.txt

                If the device connected to the port is not a TTY but a braille device, prepend "brl," before the device type, for instance console=brl,ttyS0 For now, only VisioBraille is supported.
consoleblank= [KNL] The console blank (screen saver) timeout in seconds. Defaults to 10*60 = 10mins. A value of 0
   disables the blank timer.
coredump_filter= [KNL] Change the default value for
   /proc/<pid>/coredump_filter.
   See also Documentation/filesystems/proc.txt.

http://www.nxp.com/products/automotive-products/microcontrollers-and-processors/arm-mcus-and-mpus/i.mx-application-processors/i.mx-6-processors/i.mx-6ultralite-processor-low-power-secure-arm-cortex-a7-core:i.MX6UL?tab=Design_Tools_Tab

Re: /sys folder empty after deploying the image on the SD card

lordtheo — Tue, 07 Feb 2017 15:11:36 GMT

Hi Biyong

Thank you for the help.

Following the advice from Eric Chen, I finally got it solved. The trick was to:

create this file:

root@imx6ulevk:~# cat /etc/default/weston

OPTARGS="-i30000"

-i<sec> for the idle timeout.

Best Regards,

Theo

Re: /sys folder empty after deploying the image on the SD card

b36401 — Wed, 22 Feb 2017 09:10:45 GMT

sysfs should be mounted on /sys in the filesystem. You can check it such way:

# mount|grep sysfs
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
#

I suppose it is not in your case for some reason.

There shouls be a script named like mountkernfs.sh in the system. This script mounts sysfs among other kernel filesystems. I suppose it of its work is broken somehow.

As a workaround you can mount it with the command like this:

# mount -t sysfs none /sys

Have a great day,
Victor

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