Checksum bad flashing TPL1043ND using tftpd

[ariznaf]

I have been hours trying to unbrick my TP-link TL-WR1043ND v1.3

I had bricked it trying to upload its firmware.

I have soldered the serial connections, and I have access via serial to send commands.

I have the tftp server running in my windows machine
I have stablished the ip port and the srever port
I have saved the firmware as code.bin
but when i send the comand

tftpboot 0x81000000 code.bin

it starts the transfer from the tftp server (I can see the connection in the server) and beging to transfer bytes. But I receive multiple "checsum bad" errors during the transfer.

This is the output:

dup 1 speed 1000
Using eth0 device
TFTP from server 192.168.2.1; our IP address is 192.168.2.202
Filename 'code.bin'.
Load address: 0x81000000
Loading: checksum bad
checksum bad
#################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         ##################################################checksum bad
checksum bad
###checksum bad
checksum bad
checksum bad
############
         #########checksum bad
########################################################
         #################################################################
         ######checksum bad
checksum bad
##checksum bad
checksum bad
checksum bad
##########

It seems as if some packets were corrupted during the transfer.

I have tried several firmwares, the one from tplink, older install versions of openwrt, the las install version… always with the same results.

I have even tried to continue after the transfer, copy the download one to the destination and booting from it.

cp.b 0x81000000 0xbf020000 0x7c0000
bootm 0xbf020000

But when I try to boot, it gives errors tying to unzip de firmware, and keeps rebooting

## Booting image at bf020000 ...
   Uncompressing Kernel Image ... Error: Bad gzipped data
GUNZIP ERROR - must RESET board to recover

Resetting...

What is going on?
How may upload the firmware without errors?

By the way, I am using a windows machine (no Linux desktop here).

Thank you.

[ariznaf]

I don't understand which was the problem, probably using UDP protocol in a noisy environment.

Finally I have found a kermit software for windows (kermit 95) and I have been able to upload openwrt 18.6 via serial using kermit.

Like in the old good days back to 1985 when we connected to server backbones from an PC 8086 via this terminal emulator and used it to submit binary files.

I had almost fotgotten about all this.

I have the router up and running thanks to instructions in this forum.
Thank you all.

Now I have to configure it and change it with the emergency router that I was using these days.