U-boot Auto Boot Challenge: Seeking Assistance for OpenWRT Installation on Meraki MR16

Installing and Using OpenWrt
1

Greetings everyone! :wave: I'm currently in the process of installing OpenWRT on a Meraki MR16 using the DSD TECH SH-U09C USB to TTL Serial Adapter with the FTDI FT232RL chip, from a Linux PC using Minicom. The connection has been successfully established by connecting the pins, but I'm facing a challenge—I'm unable to interrupt the U-boot Auto Boot process. It seems that the waiting period to press any key is disabled.

Does anyone have any suggestions or insights on how I can resolve this issue? Is it possible to extend the timeout to stop the Auto Boot? I would greatly appreciate any help or shared experiences in this process! :pray: #OpenWRT #MerakiMR16 #Uboot #Linux #TechnicalHelp

Boot Sequence:

U-Boot 1.1.4-g5416eb09-dirty (Mar 3 2011 - 16:28:15)

AP96 (ar7100) U-boot 0.0.1 MERAKI
DRAM: b8050000: 0xc0140180
64 MB
Top of RAM usable for U-Boot at: 84000000
Reserving 228k for U-Boot at: 83fc4000
Reserving 192k for malloc() at: 83f94000
Reserving 44 Bytes for Board Info at: 83f93fd4
Reserving 36 Bytes for Global Data at: 83f93fb0
Reserving 128k for boot params() at: 83f73fb0
Stack Pointer at: 83f73f98
Now running in RAM - U-Boot at: 83fc4000
id read 0x100000ff
flash size 16MB, sector count = 256
Flash: 16 MB
In: serial
Out: serial
Err: serial
Net: ag7100_enet_initialize...
ATHRF1E: Port 0, Neg Success
ATHRF1E: unit 0 phy addr 0 ATHRF1E: reg0 1000
eth0: 00:03:7f:e0:00:62
eth0 up
No valid address in Flash. Using fixed address
ATHRF1E: Port 1, Negotiation timeout
ATHRF1E: unit 1 phy addr 1 ATHRF1E: reg0 ffff
eth1: 00:03:7f:09:0b:ad
eth1 up
eth0, eth1
RESET is un-pushed
Hit any key to stop autoboot: 0
part0: Copying image to memory ... done.
part0: Checking sha1 (from 0x80060000 length 975288) ... match
part0: sha1 calculated: 38605dbee3ae20722f7baf28704cf9f821beda6a
## Starting application at 0x80060000 ...
starting stage2
decompressing embedded kernel image 0x81c024f0(0xebcaa)
got osize 2b7134
.....................done
2

Does the rx pin of your router work at all (interrupting or not, your key presses should be reported on the screen, maybe in u-boot or later on in the vendor firmware)?

If not, check your cables again (and the connectivity between tx of your ftdi and the rx pin of your router), quite a few vendors intentionally disconnect rx (missing rx resistors, rx pulled down to GND, etc. pp.). A visual inspection of the PCB might help answering that question.

3

It is very likely that some parameter in the nvram is responsible for the waiting period.

1 Like
5

I believe the key press time is set to 0, and I'm looking for a way to increase it. Thank you for your time.

6

I need some way to change that parameter. Thank you for your time.

7

Would it be possible to reprogram the NAND of a Meraki MR16 to modify the boot using an FTDI FT232RL?

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8

No, it's a serial adapter, not accessing the NAND directly.

2 Likes