Thanks all for ur replies. I gave a try to create a new rootfile system (ext2) by following the procedure in free-electrons.com and examples in the busybox folder. Surprisingly, it got built properly and run upto the same point and doesn't accept any commands i'm typing. I haven't added serial related stuff (gettty) in the inittab/rcS file as I am still not much clear about it. *My board setup is :* I am using JTAG debugger to load the kernel and root file system (DRAM controller initilization is done through JTAG) & then kernel and rootfs are loaded. I am getting the "printk" messages in terminal program (tera-term running in PC) Since,I am not using bootloader ,I enable console prints in the call to cosole_init in start_kernel (by adding the flags CONSOLE_PRINTBUFFER | CON_ENABLED in the struct console) Once call to console_init happens,I am starting to get print messages. *My query is:* At later point after file system mounted, is this same console used for login? (i'm having only one UART port in my board -> ttySAC0) Am I getting this err (/bin/sh: can't access tty; job control turned off) because console is locked already for printk's? *What changes are needed in the inittab & /etc/init.d/rcS file to get the working shell prompt* *for this scenario*? *below are the console messages:* RAMDISK: ext2 filesystem found at block 0 RAMDISK: Loading 3072KiB [1 disk] into ram disk... \ done. VFS: Mounted root (ext2 filesystem) readonly on device 1:0. Freeing init memory: 80K */bin/sh: can't access tty; job control turned off* / # * /etc/inittab file contents* # This is run first script ::sysinit:/etc/init.d/rcS # Start an "askfirst" shell on the console ::askfirst:/bin/sh # Stuff to do when restarting the init process ::restart:/sbin/init # Stuff to do before rebooting ::ctrlaltdel:/sbin/reboot ::shutdown:/bin/umount a r */etc/init.d/rcS file contents * #!/bin/sh mount t proc none /proc mount t sysfs none /sys exec /sbin/sh /bin/sh plz suggest me the changes required to get working shell prompt.. Thanks, On Mon, May 7, 2012 at 7:31 PM, Adam Lee <adam8157@gmail.com> wrote:
On Mon, May 07, 2012 at 06:21:05PM +0530, pcuser p wrote:
I am ending up in the shell prompt with the message as below: "entered linuxrc script" "/bin/sh: can't access tty; job control turned off / $"
my kernel commad line is "mem=32M console=ttySAC0,115200 root=/dev/ram0 init=/linuxrc initrd= 0x80800000,8M user_debug=31"
In my kernel command line(with busybox), init=/sbin/init, I drop commands into /etc/profile.
Below are my /linuxrc and /etc/inittab file contents linuxrc:
#!/bin/sh /bin/echo "entered linuxrc script" /bin/sh exec /sbin/init
Don't run sh before init, this makes the warning.
/etc/inittab:
# Run gettys in standard runlevels 3:2345:respawn:/sbin/getty 115200 ttySAC0
runlevels makes no sense here, but it should be OK.
And, I use busybox to build the rootfs for kernel debugging: https://github.com/adam8157/kernel-studio the rootfs making script is at here right now: https://github.com/adam8157/kernel-studio/blob/master/mkrootfs Might helps.
-- Regards, Adam Lee -------------------------------- E-mail: adam8157@gmail.com Website: http://adam8157.info --------------------------------