Reflash NAS540 via SD card slot? (Recover from probable Hack)

Clay_JF2019

Used notepad to edit file content. Including 2 references in script.  Seem to remember that is OK.

Anyways updated to cover if NAS540 uboot expects folder named nas5xx_fw instead of nas3xx_fw

Retrying.

Clay_JF2019

Summary:

unpacked .zip from http://downloads.zyxel.nas-central.org/Users/Mijzelf/NAS326/zyxel_support_send_instruction.zip

copied unpacked contents to

FAT formatted SD card (old FAT16 not FAT32 or other extended FAT)

edited file and folder names and file content from nas3xx to nas5xx including paths and shell script references using Notepad for internal file editing.

changed MD5sum in nas3xx_md5sum to match NAS540 firmware being flashed using Notepad
  (will recheck this. Not sure now that MD5sum was for unpacked firmware or whole download)
  (will also recheck this path)

renamed firmware to ras.bin and placed it inside renamed nas5xx_fw folder

Placed SD card in NAS540 slot

unplugged power from NAS540 
reapplied power
waited until NAS Seeker found NAS540
No Joy

repeated procedure but held reset power down as power was restored for 30 seconds
No joy

Conclusion:
I will recheck nas5xx_md5sum for correct info & if incorrect I will report results after correction

Clay_JF2019

Hmmm...It would be good to know if the reflash might have been successful but not a problem solver.

Could a successful reflash leave a hostile configuration or addons in place with a disabled reset button? 

I have been making the assumption that the NAS540 will be reset as part of firmware flash.
Or that reflash will at least restore function to the reset button. And that any corrupt add-on routines will get flushed from onboard memory. Is this a bad assumption?

The point of my reflash is to regain control by removing any changes to firmware and stored configuration including addons not stored on disks.

Clay_JF2019

MD5sum was wrong.  I had copied M5sum for whole firmware .zip.   

Applied new MD5sum for just the ras.bin firmware 639d3e791d222f65377a612cf0cb582c in this case. 

Retried.  
IDK if its different results or not.
NAS starter seems unable to detect. But had some detection issues before.

Possibly firmware download got corrupted
Will probably need to download firmware again. Confirm .zip MD5sum matches.
Plug in new firmware MD5sum and copy new ras.bin
Try yet again.

---
P. S. still do not know if I need to do more than 

remove power
insert SD
restore power
wait x minutes
run NAS Starter

IDK if there should be any buttons pushed/held down or specific lights sequence to wait on 

Clay_JF2019

Seem to have flashed something. Because NAS Starter no longer can probe NAS540 out.

Not good. But assuming it can still be recovered.

Is the uboot.bin really the same for NAS540 as NAS320? 
I can see how it might be. But I am looking for factors that might have caused bad flash.
Ones that I can correct.

Mijzelf

still do not know if I need to do more than

No. Prepare SD card, plugin, power on. Wait. That's the sequence. I *think* all buttons will be ignored, but at least not pushing them is the way to go.

Is the uboot.bin really the same for NAS540 as NAS320?

Certainly not. the NAS5xx has a different processor, and uses bootbox. But, as you can read in usb_key_func.sh, it's only flashed when the current bootloader contains the string "Oct 13 2015 - 09:25:56".

Do you have the possibility to hook up a serial port?

FrankR

I think I have the same problem after the Firmware 521AASZ2C0 was automatically installed my NAS 542 is not working any more. Somtimes I see the login screen, sometimes I can ping it. But never I got a stable connection. I already send an email to the support. But maybe anybody here has a faster solution.

Clay_JF2019

Serial port hook up possible I think. Point me toward something detailed on hook up. 

But maybe I powered off in middle of flashing.

How do I tell when flash process starts and ends?

Many of the other devices I have flashed would automatically reboot at end of successful flash. So in this case with no button pressing required to start flash process -- does flashing start again if the flash media is still inserted? 

Bottomline: is there a critical time when the media needs to be removed or device unplugged in order to have clean flash?  

If the device is supposed to shut itself off after a clean flash - that has never happened. 

Clay_JF2019

hardware-wise are we talking hooking to NAS540 USB port? Or popping off case and hooking to header on PCB?
Either way is the software hook up VT-100 emulation or what?

Mijzelf

Serial port hook up possible I think. Point me toward something detailed on hook up.

http://zyxel.nas-central.org/wiki/Serial_port_(NAS540)

How do I tell when flash process starts and ends?

According to the script the sysled is blinking orange while flashing, and the NAS switches itself off, when done.

hardware-wise are we talking hooking to NAS540 USB port? Or popping off case and hooking to header on PCB?

A header on PCB

Either way is the software hook up VT-100 emulation or what?

Command line interface to bootbox and linux.