Hi,<br>I am doing linux kernel porting for FPGA board.<br>I am facing issue in getting the shell prompt at the end of kernel booting.<br>Shell prompt is not taking any commands Im typing. <br><br>I can place break point in Tx & Rx ISR with Jtag debugger.ISR functions seems working till shell is entered (echo message in the /etc/inittab script & mounting /proc,/devtmpfs and ls command (added to check)are working, I added ls,cat command in the /etc/init.d/rcS file to check uart Tx / Rx)<br>
<br>Once the shell is entered with the below message, UART ISR is NOT invoked (using JTAG to put breakpoints) ,if I type any command & I cant get any message. <br><br><br><b>Err message:<br><br>/bin/sh: can't access tty; job control turned off<br>
<br>/ #</b>
<br><br> <br><br>Kindly share any suggestion to fix this issue.<br><b><br>Below are the /etc/initab & /etc/init.d/rcS </b><br><br><span style="background-color:rgb(51,102,255)">/etc/inittab:</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"># This is run first script</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">::sysinit:/etc/init.d/rcS</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"> </span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"># Start an "askfirst" shell on the console</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)">
<span style="background-color:rgb(255,255,0)">ttySAC0::askfirst:-/bin/sh</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">ttySAC0::respawn:-/sbin/getty 115200 ttySAC0</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"> </span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"># Stuff to do when restarting the init process</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">::restart:/sbin/init</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"> </span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"># Stuff to do before rebooting</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">::ctrlaltdel:/sbin/reboot</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">::shutdown:/bin/umount a r</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"> </span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"> </span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)"> </span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><b style="background-color:rgb(102,51,255)">/etc/init.d/rcS</b><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">#!/bin/sh</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">echo -e "\n in rcS script\n"</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">echo -e "\n Mounting proc FS\n"</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)">
<span style="background-color:rgb(255,255,0)">mount t proc none /proc</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">echo -e "\nMounting sysfs \n"</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">mount t sysfs none /sys</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">ls -alh /</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">echo -e "\n\n"</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">ls -alh /dev/ttyS*</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">echo -e "\n"</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">cat /proc/interrupts</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">echo -e "\n ttySAC0 respawning \n"</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)">
<span style="background-color:rgb(255,255,0)">ttySAC0::respawn:-/sbin/getty 115200 ttySAC0</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">echo -e "\n ttySAC0 respawning finished \n"</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">echo -e "\n exec /bin/sh\n"</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)">
<span style="background-color:rgb(51,255,51)">exec /bin/sh</span><br style="background-color:rgb(255,255,0)"><br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">ls</span><br style="background-color:rgb(255,255,0)">
<br style="background-color:rgb(255,255,0)"><span style="background-color:rgb(255,255,0)">#ls -alh /dev</span><br><br><b style="background-color:rgb(51,102,255)">Below are the console message of boot up.</b><br><br>Linux version 3.1.6-00011-g82af784-dirty (pcuser@pcuser-linux) (gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3) ) #66 Fri May 11 16:21:22 IST 2012<br>
CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=00053177<br>CPU: VIVT data cache, VIVT instruction cache<br>Machine: FPGA Board<br>Memory policy: ECC disabled, Data cache writeback<br>Available lowmem size : 32 MB<br>
Built 1 zonelists in Zone order, mobility grouping on. Total pages: 8128<br>Kernel command line: mem=32M console=ttySAC0,115200 root=/dev/ram0 init=/sbin/init initrd=0x80800000,8M user_debug=31<br>PID hash table entries: 128 (order: -3, 512 bytes)<br>
Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)<br>Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)<br>Memory: 32MB = 32MB total<br>Memory: 22456k/22456k available, 10312k reserved, 0K highmem<br>
Virtual kernel memory layout:<br> vector : 0xffff0000 - 0xffff1000 ( 4 kB)<br> fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB)<br> DMA : 0xffc00000 - 0xffe00000 ( 2 MB)<br> vmalloc : 0xc2800000 - 0xf6000000 ( 824 MB)<br>
lowmem : 0xc0000000 - 0xc2000000 ( 32 MB)<br> modules : 0xbf000000 - 0xc0000000 ( 16 MB)<br> .text : 0xc0008000 - 0xc018c000 (1552 kB)<br> .init : 0xc018c000 - 0xc01a1000 ( 84 kB)<br> .data : 0xc01a2000 - 0xc01afe00 ( 56 kB)<br>
.bss : 0xc01afe24 - 0xc01c0f24 ( 69 kB)<br>SLUB: Genslabs=13, HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1<br>NR_IRQS:32<br>Console: colour dummy device 80x30<br>console [ttySAC0] enabled<br>Calibrating delay loop... 1.86 BogoMIPS (lpj=9344)<br>
pid_max: default: 32768 minimum: 301<br>Mount-cache hash table entries: 512<br>CPU: Testing write buffer coherency: ok<br>devtmpfs: initialized<br>exceptions_init<br>Switching to clocksource timer0<br>Trying to unpack rootfs image as initramfs...<br>
rootfs image is not initramfs (junk in compressed archive); looks like an initrd<br>Freeing initrd memory: 8192K<br>msgmni has been set to 59<br>io scheduler noop registered (default)<br>brd: module loaded<br>loop: module loaded<br>
mousedev: PS/2 mouse device common for all mice<br>RAMDISK: ext2 filesystem found at block 0<br>RAMDISK: Loading 3072KiB [1 disk] into ram disk... \<br>done.<br>VFS: Mounted root (ext2 filesystem) readonly on device 1:0.<br>
devtmpfs: mounted<br>Freeing init memory: 84K<br><br><b style="background-color:rgb(255,255,0)">echo messages from /etc/rcS & /etc/inintab</b><br> in rcS script<br><br> Mounting proc FS<br><br>Mounting sysfs<br><br>drwxrwxr-x 12 0 0 1.0K May 9 2012 .<br>
drwxrwxr-x 12 0 0 1.0K May 9 2012 ..<br>
drwxrwxr-x 2 0 0 2.0K May 11 2012 bin<br>drwxr-xr-x 3 0 0 11.9K Jan 1 00:00 dev<br>drwxr-xr-x 3 0 0 1.0K May 11 2012 etc<br>drwxr-xr-x 2 0 0 1.0K May 9 2012 lib<br>
lrwxrwxrwx 1 0 0 11 May 8 2012 linuxrc -> bin/busybox<br>drwx------ 2 0 0 12.0K May 8 2012 lost+found<br>drwxr-xr-x 2 0 0 1.0K May 8 2012 proc<br>drwxrwxr-x 2 0 0 1.0K May 8 2012 sbin<br>
drwxr-xr-x 2 0 0 1.0K May 8 2012 sys<br>drwxrwxr-x 4 0 0 1.0K May 8 2012 usr<br>drwxr-xr-x 2 0 0 1.0K May 9 2012 var<br><br><br>crw------- 1 0 0 204, 64 Jan 1 00:00 /dev/ttySAC0<br>
<br><br><br> ttySAC0 respawning<br><br>/etc/init.d/rcS: line 20: ttySAC0::respawn:-/sbin/getty: not found<br><br> ttySAC0 respawning finished<br><br>-rwxr-xr-x 1 0 0 1.0K May 11 2012 /bin/hello<br><br>
calling hello world<br><br>/etc/init.d/rcS: line 24: ./hello: not found<br>/etc/init.d/rcS: line 25: hello: not found<br>/etc/init.d/rcS: line 26: ./hello: not found<br>/etc/init.d/rcS: line 27: /bin/hello: not found<br>
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exec /bin/sh<br><br><span style="background-color:rgb(255,255,51)">/bin/sh: can't access tty; job control turned off</span><br style="background-color:rgb(255,255,51)"><span style="background-color:rgb(255,255,51)">/ #</span><br>
<br>I can't type any commad at the shell prompt,<br>shell is not accepting it.<br><br><br><br>