Craig McQueen

No output of 'less' or 'screen' on imx28evk with 3.14 kernel

Discussion created by Craig McQueen on Nov 10, 2014
Latest reply on Nov 11, 2014 by Craig McQueen

I'm testing the 3.14.19 kernel on imx28evk, with a Yocto build that uses the linux-fslc kernel provider. I've added the following to my local.conf to build extra packages:


IMAGE_INSTALL_append = " lrzsz alsa-utils screen nano strace dropbear"


I've found that running Busybox 'less' and GNU 'screen' both generate no output, but seem to lock up. E.g. for 'less':


# less /etc/passwd


Nothing. Ctrl-C to quit. But ordinary 'cat' works fine:


# cat /etc/passwd root::0:0:root:/home/root:/bin/sh daemon:*:1:1:daemon:/usr/sbin:/bin/sh ... 


Busybox less can be terminated with Ctrl-C. GNU screen can't be terminated with Ctrl-C, but can be terminated with Ctrl-\.


Running strace on 'less /etc/passwd', I see the last few lines are:


# strace less /etc/passwd ... fstat64(1, {st_mode=S_IFCHR|0600, st_rdev=makedev(204, 64), ...}) = 0 readlink("/proc/self/fd/1", "/dev/ttyAMA0", 126) = 12 stat64("/dev/ttyAMA0", {st_mode=S_IFCHR|0600, st_rdev=makedev(204, 64), ...}) = 0 open("/dev/ttyAMA0", O_RDONLY|O_LARGEFILE


It halts at that point until Ctrl-C is pressed.


For GNU 'screen', it's not so obvious how to make sense of it. I will attach strace output for each.


Any suggestions on diagnosis of this would be appreciated.

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