Booting OpenWrt kernel from bootloader - printk: console [ttyS0] disabled

Installing and Using OpenWrt
1

Hi all,

I'm trying to flash OpenWRT to a Netgear WNDAP360. I've managed to connect fine via UART and write the latest kernel file to an address in memory. When I go to boot it via bootm, it gets so far before it just starts writing gibberish. Has anyone any idea whats going on here? The wiki doesn't say anything about this.

I've attached a screenshot of what happens. At this stage, I can't do anything but it appears like the access point is still booting up.

Screenshot from 2023-03-18 16-37-01
Screenshot from 2023-03-18 16-37-01770×559 94.6 KB

Thanks,
Owen

2

What commands did you run?

3

I executed as written here:

screen  /dev/ttyUSB0 9600,cs8,-parenb,-cstopb,-hupcl,-crtscts,clocal

ar7100> setenv ipaddr 192.168.1.1
ar7100> setenv serverip 192.168.1.42
ar7100> saveenv
ar7100> reset

tftpboot 0x81000000 openwrt-22.03.3-ath79-generic-netgear_wndap360-initramfs-kernel.bin

mboot 0x81000000

It is noting there are no files with -UImage anymore. It is just "-kernel".

Then that's when I get the output as shown in the screenshot.

Thanks,
Owen

4

You may need to change the port speed to 115200 at some point.

5

Any ideas how I would I be able to do that within screen once I've executed mboot?

6

I suppose you can simply re-open it with the proper baudrate.
Alternatively you can use a terminal program like picocom where you can change parameters interactively, ^a ^b as a I recall.

1 Like
7

Thanks Andrew, I'll give it a go.

8

Once it starts booting, do you get a DHCP address? Should just be able to continue the instructions.

9

I thought that however when I tried pinging 192.168 1.1 there was no response.

10

I can now enter the root@openwrt command line thanks to connecting via 115200 baud rate. However it seems like it enters a blocking state followed by a forwarding state the eth0 adapter and I can no longer ping the computer the tftp server is on. Seems like something has changed in openwrt recently to break it this much.

11

If you see something like this - that's absolutely normal.

[   22.013513] br-lan: port 2(lan2) entered blocking state
[   22.023969] br-lan: port 2(lan2) entered forwarding state

Check your IP address with ip a

12

Thank for confirming. It states it's set to 192.168.1.1 for the br-lan interface for inet which was what I set in uboot prior to downloading the initramfs file. I can't ping the tftp server and vice versa I can't ping the access point.

13

Make sure you're connected to the port that is a member of br-lan
The address you see in OpenWrt has nothing to do with the address in u-boot.

14

Yeah I am, the access point only has one ethernet port. That is connected to a switch and my computer (tftp server) is also connected to that switch.

15

That's weird... please show the output of

ip a
ip l
arp -a
16

Sure. As requested:

ip a
ip a

ip l
ip l

arp -a
arp -a

It's worth noting my tftp server computer address is 192.168.1.2.

Thanks,
Owen

17

It appears they've spoken about the issue here:

I had to drop my connection speed from 1000Mb/s to 100Mb/s Half-Duplex (unsure if Full-Duplex works) and it managed to ping. This seems like a pretty bad issue, i'll be curious if a fixed is released soon.

Thanks,
Owen

1 Like