Before Netinstall, you could try option 'e' in the RouterBOOT menu to format the NAND. Then attempt Netinstall again.

-- Nathan

Do you realy want to format your storage device?
that would result in losing all your data
type "yes" to confirm: yes
formatting nand... done!

, but it seems as though RouterBOOT can memorize the offset of the kernel on the boot partition and in certain circumstances continue to attempt to load the kernel from that offset even if it isn't located there anymore.

Nathan ... Question for ya .... If you have created a primary and fallback partition, would this suspect RouterBOOT issue affect the booting of both partitions, being a low level operation? Or would just one be impacted and the other will boot normally?

It's possible that your flash did indeed fail and is physically defective. But it's also possible that this is a RouterBOOT bug...it's not exactly the same, but it is similar enough to what some CRS317 owners reported here to make me suspicious: thread link

CRS3xx and RB450Gx4 are both ARM-based, so this could be a related ARM RouterBOOT issue. But best bet is probably to talk to support@mikrotik.com via e-mail to see what they say.

I have noticed strange behavior with more recent RouterBOOTs, at least on some other architectures like mmips. I have not tested ARM RouterBOOT yet, but it seems as though RouterBOOT can memorize the offset of the kernel on the boot partition and in certain circumstances continue to attempt to load the kernel from that offset even if it isn't located there anymore. (Please note that this is just a theory based on some interesting observations I've made on boards that use smaller SPI NOR flash instead of parallel NAND, and is not confirmed.)

It would be interesting to have you try the following:

1) Do a format via RouterBOOT (option 'e'), as you have already tried.
2) After format, instead of proceeding to Netinstall, have RouterBOOT try to boot from flash even though you know it will fail (because it's empty).
3) After this, go ahead and also reset RouterBOOT settings back to defaults (option 'r').
4) Let RouterBOOT yet again try to boot from the empty flash memory, and fail.
5) After these steps, try Netinstall again, and see what happens.

If you hear from MikroTik support, please update us here; I am very curious about the outcome of this specific problem.

-- Nathan

your choice: e - format nand


Do you realy want to format your storage device?
that would result in losing all your data
type "yes" to confirm: yes
formatting nand... done!

RouterBOOT backup booter 6.42

RB450Gx4

CPU frequency: 716 MHz
  Memory size: 1024 MiB
    NAND size: 512 MiB

Press any key within 2 seconds to enter setup..

loading kernel... kernel not found or data is corrupted
Please, check ethernet cable...

Welcome to MikroTik Router Software remote installation 6.42.7
Press Ctrl-Alt-Delete to abort

mac-address: CC:2D:E0:F4:3F:79
mac-address: CC:2D:E0:F4:3F:78
mac-address: CC:2D:E0:F4:3F:77
mac-address: CC:2D:E0:F4:3F:76
mac-address: CC:2D:E0:F4:3F:7A

software-id: ****-**** key:
**********************************

Waiting for installation server...
Found server at 08:00:27:47:2B:C6

Formatting disk.........

installed routeros-arm-6.42.7                                                
Writing configuration...

Software installed.
Press ENTER to reboot

Nathan ... Question for ya .... If you have created a primary and fallback partition, would this suspect RouterBOOT issue affect the booting of both partitions, being a low level operation? Or would just one be impacted and the other will boot normally?

`
Good question, since I am mainly basing my guess on experiences I've had while playing with newer RouterBoards that have smaller NOR flash (16MiB) that RouterBOOT won't let you partition (where RouterBOOT is still YAFFS-aware but can look inside of "/bootimage" -- which is really just the system NPK -- for the kernel itself). I don't know whether RouterBOOT on a device with large NAND would behave the same way, and I don't even know for sure that there is an actual problem...this is all just a hypothesis at this point that still needs further testing.

However, you bring up a good point: it might be worth attempting to have RouterBOOT format the flash, and then also divide it up into 2 or more partitions before attempting Netinstall again. That could potentially break the "spell" and at least get boldrouter's Gx4 back up and running.

-- Nathan

Cool beans, though updating the firmware really shouldn't have been "necessary" per-se. If that fixed it, that tells me that either there was a bug in the older bootloader that you somehow managed to trip and which was fixed in the updated loader, or there was actually some change in how some newer versions of 6.42.x are being packaged that requires a bootloader update to be understood. The latter seems less likely than the former to me.

-- Nathan