Zyxel NSA325 messed up uboot - recovery - de-brick

@brodhi

i have a 2nd nsa325 which i fu**ed up some years ago while flashing uboot (maybe corrupt).
now i tried to kwboot it but it works only parcially:

Zyxel-NAS325-OpenWRT$ kwboot -t -B 115200 /dev/ttyUSB0 -b uboot.2025.10-tld-1.nsa325.kwb -p
kwboot version 2025.01
Detected kwbimage v0 with NAND boot signature
Patching image boot signature to UART
Sending boot message. Please reboot the target...|
Sending boot image header (512 bytes)...
 25 % [....                                                                  ]
Done
Sending boot image data (518268 bytes)...
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Done
Finishing transfer
[Type Ctrl-\ + c to quit]

and thats it. i tryed several uboots which is know are working (tested on the 2nd box).

i also read: https://forum.doozan.com/read.php?4,140145,140214

any tips what to do?



Edited 1 time(s). Last edit at 12/03/2025 07:16AM by Sash.

Let me move this thread back to U-Boot section. This Rescue section is for OpenWRT and other older rescue systems.

-bodhi
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Sash,

Try using my kwboot build. It is more resilient in error recovery.

U-Boot flashing utilities and kwboot binary

Quote

Update Mar 02, 2024

1 . If you are installing u-boot and Debian rootfs on Kirkwood boxes for the first time, you can use the latest flashing utilities on the rootfs itself. No need to download the binpack. But if you'd prefer to have a tool box just in case, then the binaries in the binpack will be handy to have. For kwboot, please download the latest kwboot binary attached to this post.

2. I've attached the 2024.04 kwboot static binary (ARM) to this post (this kwboot binary can be run on any ARM box):
kwboot_static_2024.04-rc3

-bodhi
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Edited 1 time(s). Last edit at 12/03/2025 02:42PM by bodhi.

no enhancement of the trixi delivered kwboot

./kwboot_2025.01-rc1_x86-64 -t -B 115200 /dev/ttyUSB0 -b uboot.2025.10-tld-1.nsa325.kwb -p
kwboot version 2025.01-rc1-ge61ea9f2e5d2-dirty
Detected kwbimage v0 with NAND boot signature
Patching image boot signature to UART
Sending boot message. Please reboot the target...-
Sending boot image header (512 bytes)...
 25 % [....                                                                  ]
Done
Sending boot image data (518268 bytes)...
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Done
Finishing transfer
[Type Ctrl-\ + c to quit]

Try the normal ARM version kwboot_2024.04-rc3 (it's the same as the static version but load share libs dynamically).

Quote

Update Feb 29, 2024

1 . If you are installing u-boot and Debian rootfs on Kirkwood boxes for the first time, you can use the latest flashing utilities on the rootfs itself. No need to download the binpack. But if you'd prefer to have a tool box just in case, then the binaries in the binpack will be handy to have. For kwboot, please download the latest kwboot binary attached to this post.

2. I've attached the 2024.04 kwboot binary (ARM) here:
kwboot_2024.04-rc3
(kwboot version 2024.04-rc3-00001-g0861eab8ec)
md5:
a86a783a5b7860397ef3fa6a98d031bf kwboot_2024.04-rc3
sha256:
8ec524a1f5d7475b7df059e40366f3cbc7a94babf91db3c84e0faaae4cc1ab90 kwboot_2024.04-rc3

Also, on the ARM box that you run kwboot, get some info

uname -a
gcc --version
cat /etc/os-release

-bodhi
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Edited 1 time(s). Last edit at 12/04/2025 03:19PM by bodhi.

havent noticed u replied....

root@PHILAP0112:# uname -a
Linux PHILAP0112 6.12.57+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.57-1 (2025-11-05) x86_64 GNU/Linux
root@PHILAP0112:# gcc --version
gcc (Debian 14.2.0-19) 14.2.0
Copyright (C) 2024 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

root@PHILAP0112:# cat /etc/os-release 
PRETTY_NAME="Debian GNU/Linux 13 (trixie)"
NAME="Debian GNU/Linux"
VERSION_ID="13"
VERSION="13 (trixie)"
VERSION_CODENAME=trixie
DEBIAN_VERSION_FULL=13.2
ID=debian
HOME_URL="https://www.debian.org/";
SUPPORT_URL="https://www.debian.org/support";
BUG_REPORT_URL="https://bugs.debian.org/";
root@PHILAP0112:#

both kwboot binaries error

@PHILAP0112:~/Downloads/Zyxel-NAS325-OpenWRT$ chmod +x kwboot_2024.04-rc3 
@PHILAP0112:~/Downloads/Zyxel-NAS325-OpenWRT$ chmod +x kwboot_static_2024.04-rc3
@PHILAP0112:~/Downloads/Zyxel-NAS325-OpenWRT$ ./kwboot_2024.04-rc3 -t -B 115200 /dev/ttyUSB0 -b uboot.2025.10-tld-1.nsa325.kwb -p
bash: ./kwboot_2024.04-rc3: Kann die Binärdatei nicht ausführen: Fehler im Format der Programmdatei
@PHILAP0112:~/Downloads/Zyxel-NAS325-OpenWRT$ sudo ./kwboot_2024.04-rc3 -t -B 115200 /dev/ttyUSB0 -b uboot.2025.10-tld-1.nsa325.kwb -p
./kwboot_2024.04-rc3: 1: Syntax error: word unexpected (expecting ")")
@PHILAP0112:~/Downloads/Zyxel-NAS325-OpenWRT$ sudo ./kwboot_static_2024.04-rc3 -t -B 115200 /dev/ttyUSB0 -b uboot.2025.10-tld-1.nsa325.kwb -p
./kwboot_static_2024.04-rc3: 7: Syntax error: word unexpected (expecting ")")

Edited 1 time(s). Last edit at 12/22/2025 08:32AM by Sash.

Sash,

> root@PHILAP0112:# uname -a
> Linux PHILAP0112 6.12.57+deb13-amd64 #1 SMP
> PREEMPT_DYNAMIC Debian 6.12.57-1 (2025-11-05)
> x86_64 GNU/Linux

It is x86_64 box, so you can not use ARM binaries such as kwboot_2024.04-rc3 or or kwboot_static_2024.04-rc3. You have to use either the x86_64 binary kwboot_2025.01-rc1_x86-64, or one that comes with the distro on your PHILAP0112 box.

Or run the ARM kwboot on the good NSA325 to troubleshoot the bricked one.

-bodhi
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Edited 1 time(s). Last edit at 12/22/2025 08:33PM by bodhi.

ah ok. didnt notice that they where arm versions. ok the good thing is i made some connectors to the outside of the working one so i can try that from within openwrt. will report back

now im connecting nsa to nsa.

the baudrate in the static image cant be set

root@Zyxel-NSA325:/tmp# ./kwboot_static_2024.04-rc3 -t -B 9600 /dev/ttyS0 -b uboot.2025.10-tld-1.nsa325.kwb -p
kwboot version 2024.04-rc3-00001-g0861eab8ec-dirty
Detected kwbimage v0 with NAND boot signature
Patching image boot signature to UART
Cannot inject code for changing baudrate into v0 image header
uboot.2025.10-tld-1.nsa325.kwb: Invalid image.

on standard baudrate the transfer fails

root@Zyxel-NSA325:/tmp# ./kwboot_static_2024.04-rc3 -t /dev/ttyS0 -b uboot.2025.10-tld-1.nsa325.kwb -p
kwboot version 2024.04-rc3-00001-g0861eab8ec-dirty
Detected kwbimage v0 with NAND boot signature
Patching image boot signature to UART
Sending boot message. Please reboot the target...-
Sending boot image header (512 bytes)...
  0 % [+++++++++++++++EE
xmodem: Bad message
root@Zyxel-NSA325:/tmp#

also its very slow.

i tested the connection/cables to a ttl converter and there it works. cables about 25cm.

i guess the hw watchdog kicks (blue LED blinks on transfer abort) in cause the transfer so slow?



Edited 1 time(s). Last edit at 12/23/2025 02:03PM by Sash.

Sash,

> i tested the connection/cables to a ttl converter
> and there it works. cables about 25cm.

That what I meant. You need to use the USB ttl converter. Plug the USB converter into the good NSA325 (instead of the PHILAP0112), and run ARM kwboot on this box.

-bodhi
===========================
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got it!


but no, nothing new.

root@Zyxel-NSA325:/tmp# chmod +x kwboot_*
root@Zyxel-NSA325:/tmp# ./kwboot_static_2024.04-rc3  -t -B 115200 /dev/ttyUSB0 -b uboot.2025.10-tld-1.nsa325.kwb -p
kwboot version 2024.04-rc3-00001-g0861eab8ec-dirty
Detected kwbimage v0 with NAND boot signature
Patching image boot signature to UART
Sending boot message. Please reboot the target...|
Sending boot image header (512 bytes)...
 25 % [....                                                                  ]
Done
Sending boot image data (518268 bytes)...
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Done
Finishing transfer
[Type Ctrl-\ + c to quit]

and the 2nd kwboot gives me

root@Zyxel-NSA325:/tmp# ./kwboot_2024.04-rc3 
-ash: ./kwboot_2024.04-rc3: not found
root@Zyxel-NSA325:/tmp# ls -l
-rw-r--r--    1 root     root            27 Dec 24 00:14 TZ
-rw-r--r--    1 root     root           179 Jan  1  1970 board.json
-rw-r--r--    1 root     root             0 Dec 24 00:14 dhcp.leases
drwxr-xr-x    2 root     root            40 Dec 24 00:14 dnsmasq.cfg01411c.d
drwxr-xr-x    3 root     root            80 Dec 24 00:14 etc
drwxr-xr-x    2 root     root            60 Dec 24 00:14 hosts
-rwxr-xr-x    1 root     root         31804 Dec 24 00:14 kwboot_2024.04-rc3
-rwxr-xr-x    1 root     root        788416 Dec 24 00:14 kwboot_static_2024.04-rc3
drwxr-xr-x    3 root     root            60 Dec 24 00:14 lib
drwxrwxrwt    2 root     root           400 Dec 24 00:14 lock
drwxr-xr-x    2 root     root            80 Dec 24 00:09 log
-rw-------    1 root     root         10559 Dec 24 00:14 luci-indexcache.9ef6742f.json
drwxr-xr-x    2 root     root            40 Dec 24 00:14 odhcpd-piofolder
drwxr-xr-x    2 root     root            40 Dec 24 00:14 opkg-lists
drwxr-xr-x    2 root     root            40 Jan  1  1970 overlay
-rw-r--r--    1 root     root            47 Dec 24 00:14 resolv.conf
drwxr-xr-x    2 root     root            60 Dec 24 00:14 resolv.conf.d
drwxr-xr-x    5 root     root           240 Dec 24 00:14 run
drwxrwxrwt    2 root     root            40 Dec 24 00:14 shm
drwxr-xr-x    2 root     root            80 Dec 24 00:14 state
drwxr-xr-x    2 root     root            80 Jan  1  1970 sysinfo
drwxr-xr-x    2 root     root            40 Dec 24 00:09 tmp
-rw-r--r--    1 root     root        524288 Dec 24 00:14 uboot.2025.10-tld-1.nsa325.kwb
drwx------    3 root     root            60 Dec 24 00:14 usr
root@Zyxel-NSA325:/tmp#

Edited 1 time(s). Last edit at 12/23/2025 05:20PM by Sash.

Sash,

> but no, nothing new.

OK. So it seems to be stuck in starting u-boot (i.e. some weird state in the strapping register was set). We need more debug configured in to hopefully see more info.

Unfortunately, I'm out of time. If you want, check back here in a couple months, when I will be available with more free time.

-bodhi
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Sash,

Try this test.

Connect serial console, but don't run kwboot. Run a normal serial console (i.e. minicom/picocom). Don't power up yet.

- On the NSA325 header, unplug the RX pin, and keep the TX and GND connected.
- Power up and within 0.5 - 1.0 second, plug in the RX pin.
- If nothing came out of serial console, power down. Try again with a different wait time, e.g. 0.2 seconds.

If not working, try the same test, but with the TX pin.

Here I think with a breadboard(? I haven't used one for many years), you can connect/disconect the wire easier than using you hand.

-bodhi
===========================
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Edited 1 time(s). Last edit at 12/25/2025 05:05PM by bodhi.

What do you expect to happen?

more than

Welcome to minicom 2.10

OPTIONS: I18n 
Port /dev/ttyUSB0, 12:40:45 

Press CTRL-A Z for help on special keys

�

Sash,

I'm not "expecting" but hoping to see if we can trick the BootROM. As mentioned, if somehow the strapping register was corrupted, it could be stuck trying to read an unsuported source.

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so this should also view on 115200 baud?

> so this should also view on 115200 baud?

Of course, this box only works with 115200.

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