[BusyBox 0003114]: 64 char limit per line limit at serial port terminal

bugs at busybox.net bugs at busybox.net
Fri Apr 25 18:48:22 UTC 2008


The following issue has been CLOSED 
====================================================================== 
http://busybox.net/bugs/view.php?id=3114 
====================================================================== 
Reported By:                svolpe
Assigned To:                BusyBox
====================================================================== 
Project:                    BusyBox
Issue ID:                   3114
Category:                   Standards Compliance
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     closed
Resolution:                 open
Fixed in Version:           
====================================================================== 
Date Submitted:             04-25-2008 04:56 PDT
Last Modified:              04-25-2008 11:48 PDT
====================================================================== 
Summary:                    64 char limit per line limit at serial port terminal
Description: 
I have noticed that if you exceed 64 characters on a serial login console
that when you go to backspace (delete characters using the backspace key
or moving back characters using the left arrow key) and hit the 64
character
mark that the cursor automatically jumps up one line. 
Example: (using 10 characters instead of 64 to save space)

Grabbed from console, (% represents cursor location):

root at localhost:/$
root at localhost:/$ cp /homme/root/.ssh/known_hosts_hosts . %

ok so I have a typo homme and want to backspace (using left arrow key) and
fix it:

Right before the line jump (11 characters from the left):
root at localhost:/$
root at localhost:/$ cp /homme/r%oot/.ssh/known_hosts_hosts .

Now I hit the left arrow key one more time:
root at localhost:/$           %
root at localhost:/$ cp /homme/r%oot/.ssh/known_hosts_hosts .
and the cursor is now on the line above the command.  The interesting
thing is it is only displayed on that line but behaves as if it is still
on the line below.  If I would type some character and hit enter it would
run the command with the characters typed in were the cursor *should* be
even though the characters were typed on the line above that location.  It
sounds like this is not a big issue but if you need to delete a typo and
type something new in you need to count backspaces so you know were the
cursor should be.



====================================================================== 

---------------------------------------------------------------------- 
 svolpe - 04-25-08 05:00  
---------------------------------------------------------------------- 
I guess the bug tracker removes leading white spaces.  In my above example
the cursor jumped up a line but kept its position my example showed the
cursor (after line jump) above the r in root and not all the way to the
left by the $ as now it looks in the example. 

---------------------------------------------------------------------- 
 bernhardf - 04-25-08 05:22  
---------------------------------------------------------------------- 
1) Please retry with current trunk or at least 1.10.1
2) Please give details about the toolchain you use 

---------------------------------------------------------------------- 
 svolpe - 04-25-08 10:26  
---------------------------------------------------------------------- 
Ok, I compiled and installed busybox 1.10.0.  My system still behaves the
same and has the line jumping issue.  Interesting enough, I have now
spoken with 3 developers (from different companies) that say all of their
embedded systems have the same issue, they just never had time to
troubleshoot it and never reported it.  Everyone just uses ssh which is
what I normally do but I'm running some stress testing and do not want the
network running during the test.

I think I forgot to mention that busybox is flawless when I'm logged in
via ssh, the line jumping only occurs from the serial console.  I keep
referring to busybox as the source of the problem but I can not say that
with 100% confidence the only reason why I'm starting with it is the
problem spans multiple hardware platforms and multiple versions of the
kernel with busybox being the main common denominator. 

---------------------------------------------------------------------- 
 svolpe - 04-25-08 10:42  
---------------------------------------------------------------------- 
Screen Text:
I typed in root at endor:~#
1234567890123456789012345678901234567890123456789012345678901234

"123456789012345678901234567890123456789012345678901234567890123" is
the point right after the cursor jumped up to the line above.
below is what happened
root at endor:~# strace -o strace.log ash
ptrace: umoven: Input/output error
ash: 123456789012345678901234567890123456789012345678901234567890123: not
found

Attached is the strace log.
I have also repeated the bug using the following serial emulator
programs:
Terra Term
Hyperterm
Putty
Minicom

Regards,
Shane 

---------------------------------------------------------------------- 
 vda - 04-25-08 11:47  
---------------------------------------------------------------------- 
"Fix" is uploaded. But you really need to let ash know terminal width,
otherwise all bets are off. 

---------------------------------------------------------------------- 
 vda - 04-25-08 11:48  
---------------------------------------------------------------------- 
Fixed in revision 21870. 

Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
04-25-08 04:56  svolpe         New Issue                                    
04-25-08 04:56  svolpe         Status                   new => assigned     
04-25-08 04:56  svolpe         Assigned To               => BusyBox         
04-25-08 04:56  svolpe         File Added: busybox-config                    
04-25-08 05:00  svolpe         Note Added: 0007144                          
04-25-08 05:22  bernhardf      Note Added: 0007154                          
04-25-08 10:26  svolpe         File Added: busybox_1.10.0_config                
   
04-25-08 10:26  svolpe         Note Added: 0007184                          
04-25-08 10:42  svolpe         Note Added: 0007194                          
04-25-08 10:43  svolpe         File Added: strace.log                       
04-25-08 11:46  vda            File Added: 7.patch                          
04-25-08 11:47  vda            Note Added: 0007204                          
04-25-08 11:48  vda            Status                   assigned => closed  
04-25-08 11:48  vda            Note Added: 0007214                          
======================================================================




More information about the busybox-cvs mailing list