I finally succeed to launch a bash shell as root using telnet and wifi... (vi is also available as text editor)
I have changed ulimit to unlimited as described and successfully launch KOReader from command line, it generates a core file, crash log with segfault in koreader folder but core file size is 0 bytes and its content is really empty...
Here is a part of set command, ulimit value (after it has been changed) and core result:
Code:
HOME=/
HOSTNAME=pocketbook
HOSTTYPE=arm
IFS=$' \t\n'
LINES=24
MACHTYPE=arm-none-linux-gnueabi
MAILCHECK=60
OLDPWD=/mnt/ext1/applications
OPTERR=1
OPTIND=1
OSTYPE=linux-gnueabi
PATH=/mnt/ext1/system/bin:/sbin:/bin:/usr/bin
PIPESTATUS=([0]="0")
PPID=1125
PS1='\s-\v\$ '
PS2='> '
PS4='+ '
PWD=/mnt/ext1/applications/koreader
QT_QPA_PLATFORM=pocketbook
SHELL=/bin/sh
SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments
SHLVL=1
TERM=vt102
UID=101
USER=root
_=clear
partitions=
bash-4.1$
bash-4.1$ ulimit
unlimited
bash-4.1$ ls -al
drwxrwxrwx 7 root root 4096 Feb 11 07:33 common
-rwxrwxrwx 1 root root 0 Feb 12 20:20 core
-rwxrwxrwx 1 root root 36421 Feb 12 20:20 crash.log