Serial Port Console ttySAC0

I would like to use the main RS232 serial port (ttySAC0) for general
purpose use.  However, the port is not available since it is being used by
the console.  I would like information on the following:
1. What process is driving the serial port remote console.
2. Where in the boot process is the serial port console process invoked.
3. How do I disable the serial port console either in terminal, c code, or
in modifying the startup scripts.
I am running Qtopia with kernel 2.6.32.2.

Hi, 

You should take a look at supervivi boot parameters to change this feature.

Remember there's 3 serial com ports available, you could use any or none of
them as console, just configure it on supervivi.

Regards

Hi

If you are using U-Boot
bootargs_base=console=ttySAC0,115200 noinitrd

That is why you are getting.


When Pstree and find its source.
Now here i tried to find minicom

─gnome-terminal─┬─bash───pstree
     │                ├─bash───minicom

thank you

Thanks guys,

I temporarily left this issue since I got an external serial adapter for
the ttySAC1 port.  I'll look into this again when I get a chance.

jrh

Hi,

I'm on a similar dev : using the COM1 and COM2 and
I don't understand your answers here because these 2 are TTL levels only,
not RS 232.

SO how can you use them from super vivi or Uboot ?

mouha,

Try this link:

http://www.andahammer.com/minirs23/?PHPSESSID=b9091f282a68b63dff592aad96...

This is an adapter that converts from ttl to RS232. Regardless of whether
you convert them or not, you still access them the same way in code.  And,
if supervivi can change how they are used, they are treated the same in
supervivi as well.

jrh

"noinitrd root=/dev/mtdblock2 init=/linuxrc console=ttySAC1,115200" did the
trick.  I now can use ttySAC0 for my apps.

In supervivi:
[s] Set the boot parameters 
...
[s] Set parameter 
linux_cmd_line
"noinitrd root=/dev/mtdblock2 init=/linuxrc console=ttySAC1,115200" 

If anyone decides to do this, I recommend you first back up your NAND flash
first.  The first time I attempted to convert my debug console to ttySAC1,
the reboot resulted in a "Failed to execute /linuxrc" error.  When trying
to reflash via supervivi I then got the error: zImage file too large
(http://www.friendlyarm.net/forum/topic/541).  Apparently there is a fix
for this, but unless you are ready to JTAG your boot loader, it may be
easier to simply reload the binary image you previously saved.

[u] Backup NAND Flash to HOST through USB(upload) 
[r] Restore NAND Flash from HOST through USB 

Thanks to eduardo and alxander for your prompt replies.

James

Parameters passed to kernel can be seen in /proc/cmdline file. See below
for console output:

[root@FriendlyARM /etc]# cat /proc/cmdline 
root=/dev/mtdblock2 rootfstype=yaffs2 init=/linuxrc console=ttySAC0,115200
[root@FriendlyARM /etc]# 

Piter.

Hi,

I would like to use ttySAC0, ttySAC1 and ttySAC2 too. 
How can I do that? 
I mean I don't need console.

Thanks,

- Connect FriendlyARM to your PC via serial (115200, 8, N, 1)
- Boot in NOR mode
- [s] Set the boot parameters
- [v] View the parameter table
–> It will print something like that (the last line):
Linux command line: noinitrd root=/dev/mtdblock3 init=/linuxrc
console=ttySAC0
- [s] Set parameter
- Enter the parameter's name(mach_type, media_type, linux_cmd_line, etc):
linux_cmd_line
- Enter the parameter's value(if the value contains space, enclose it with
") (REPLACE "console=ttySAC0" FROM PARAMETER TABLE WITH "console=null",
WRITE IN ON A SINGLE LINE):
"noinitrd root=/dev/mtdblock3 init=/linuxrc console=null"
- [w] Write the parameter table to flash memeory
- (You can verify it:) [v] View the parameter table; you should see your
command
- [q] Quit
- Try [b] Boot the system
(If it does not work, turn the device off, switch it back to NAND boot mode
and turn it back on.)
(When the device boots correctly, it should write just 'Booting
Linux......' and 'Uncompressing Linux......' via serial. Then it should not
send anything, but it should boot normally on the screen – picture of Tux,
Starting leds, webserver, Qtopia - depending on your settings.)
Hope it helps.

Hi all, 
i just own a mini6410 and i just realized that COM0 is only for console.
can i change the console to another ttySAC through the instalation
FriendlyARM.ini file? 

##############
Linux-BootLoader = superboot-6410.bin
Linux-Kernel = Linux/zImage
Linux-CommandLine = root=/dev/mtdblock2 rootfstype=yaffs2 init=/linuxrc
console=ttySAC0,115200 

#change it to ttySAC3 ?

Linux-RootFs-InstallImage = Linux/rootfs_qtopia_qt4.img
Linux-RootFs-RunImage = Linux/rootfs_qtopia_qt4.ext3
#############


Thanks.

Well

Hi all, it works, now i can use COM0 for general purpose and console is
changed to ttySAC3.

Well.

Please can anyone tell me how to disable Serial Port console for use in Win
CE 6.0 ? I have tried the above commands but it does not disable serial
console messages. Please guide quick

I would like to use the main RS232 serial port (ttySAC0) for general
purpose use.  However, the port is not showing anything also has a ttySAC0
in dev folder....but when i run build in programmme serial test and set
port ttySAC0 as baud rate 115200 ans short Tx and Rx ..send something it
doesn't show anything...
can anyone tell where is the problem


I am running Qtopia with kernel 2.6.32.2.