Olimex Support Forum

Hello everybody,

If you remember I'm the person who converted an A13-based tablet board to a development board with the help of OlinuXino ready-to-use Debian images. (https://www.olimex.com/forum/index.php?topic=3520)

OK? Now I have another problem! As you may know, I built a small PCB and glued it on the original PCB, then connected it's traces to the A13 CPU using very very small wires. It has many LEDs and a pin header and I use it for my experiments.


So, I don't have access to the ttyS0 port, because it's on the other side of the CPU, and I couldn't find a reliable way to connect it to my PCB. But I have the ttyS1 port on my pin header and was able to run a getty on it and use a serial terminal beside the normal WiFi+SSH connection.

I need to completely replace ttyS0 to ttyS1. I mean all of the debugging messages and kernel messages should be printed on ttyS1 instead of ttyS0 and the main console should be ttyS1. So, I added this to uEnv.txt as my Linux kernel boot parameter:

console=ttyS1,115200

No success! Nothing prints on ttyS1 until the login prompt appears. I Also changed the script.fex to numbers 0-3 as the uart_debug_port parameters, I added the exact uart_force_debug section to it, but still no success.

Can anybody help me? Does anyone has experience with this?

Any help will be appreciated and I will be very thankful for your advises. Thank you all in advance.

And again, sorry if English me bad!  ;)

How does look the whole kernel commandline? (e.g. cat /proc/cmdline)

Quote from: MBR on November 11, 2014, 10:50:57 PM
How does look the whole kernel commandline? (e.g. cat /proc/cmdline)

cat /proc/cmdline

console=ttyS0,115200 root=/dev/mmcblk0p2 rootwait loglevel=8 panic=10 console=ttyS1,115200 root=/dev/nandb nand_root=/dev/nandb rootwait panic=10 sunxi_ve_mem_reserve=0 sunxi_g2d_mem_reserve=0 sunxi_no_mali_mem_reserve sunxi_fb_mem_reserve=0

I'm not sure how the linux kernel process the same parameters with different values, but it's possible that the second console= has no effect.

The other args are a mess, too.  I hope they don't mean everything else is!!

John