Can't flash Netgear RBR50 V1 - nprmflash bailing out

Installing and Using OpenWrt
1

After an aborted start trying to get a Netgear RBR50 V2 to flash and finding out it's not supported,

I've got my hands on a spare RBR50 V1 to try and flash OpenWRT onto. I know this is a V1 as it has the USB port on the back.

So I can factory reset the Netgear RBR50 V1 (from now on I'll just say RBR50) by pressing the reset button and holding it down. I've done that probably 15x now to set it back to the beginning so that works very well.

A summary of what I have tried to do is below. More details are below that,

  1. I tried to flash the RBR50 from the GUI with openwrt-23.05.5-ipq40xx-generic-netgear_rbr50-squashfs-factory.img on the faint chance that might work. Not surprisingly that didn't work, but was worth a shot.

  2. I then moved to using nmrpflash. I've tried using this on the RBR50 V2 and managed to get it to connect but the image didn't take. I have since found out that the V2 hardware is not supported so I got another RBR50 V1 to test on.

    I never managed to get nprmflash to send the image. I'll provide more details below.

  3. I then tried using artmtd to set the partition to 02 and then use the local GUI to upload the image as per the instructions here https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=2cb24b3f3cd89692f3c0bd137f3f560ada359bfa

None of these methods worked.

More detail

nmrpflash

  1. This was all done on a dedicated Mac, using two different Ethernet cables, both checked that they work correctly. One was a patch cable and one was a 'normal' Ethernet cable in case the cable needed to be one or the other. Always had -vv or -vvv flags. Never got any more detail.

  2. Downloaded the latest Mac version from https://github.com/jclehner/nmrpflash

  3. Checked the interfaces using nmrpflash -L and it shows that en0 was the wired connection.

  4. The image file used was openwrt-23.05.5-ipq40xx-generic-netgear_rbr50-squashfs-factory.img and appears to be the correct one based on a) the name and b) https://firmware-selector.openwrt.org/?version=23.05.5&target=ipq40xx%2Fgeneric&id=netgear_rbr50

  5. Ran the nrmpflash program as root with a wide number of parameters
    5.1. ./nrmpflash -vv -i en0 -f openwrt-23.05.5-ipq40xx-generic-netgear_rbr50-squashfs-factory.img

    The program would start up, wait for a connection or I could press control-C,

nmrpflash 0.9.24
Waiting for Ethernet connection (Ctrl-C to skip).
Skipped.
Adding 10.164.183.252 to interface en0.
Advertising NMRP server on en0 ... \
No response after 60 seconds.
Bailing out
  1. I have tried setting the IP address for both the host and the target device using -A and -a. Still no response from the RBR50.
  2. I have tried the -B flag. No response from the RBR50.
  3. I have reset the RBR50 circa 15x time and set up each time.
  4. I've read https://github.com/jclehner/nmrpflash and followed the debugging directions.
  5. I've read https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=2cb24b3f3cd89692f3c0bd137f3f560ada359bfa and it simply doesn't work for me.
  6. I've downgraded the Netgear firmware to older versions so I can enable telnet. I've then set artmtd -w boot_part 02 so I can theoretically upload the OpenWRT image from the GUI. Doesn't work.
  7. I've set the IP address of the local Macbook to a 10.164.183.253 address and it didn't work.
  8. I've set the IP address of the local Mac to 192.168.1.2 and to 192.168.2.2 and used the various nrpmflash flags to set the target values.

I have never got a single sync back from the RBR50 V1. I can reflash the RBR50 V1 by doing a factory reset and it works so it's not bricked. But nothing I do gets even a hint there is a connection. The cable works as I can then connect to the RBR50V1 after a factory reset.

To me it's as if the RBR50V1 doesn't go into the mode for ever receiving a file. The V2 model did but that doesn't work as it's different hardware.

Any and all advice welcome.

Rob