How to flash u-boot?

[dopesoul]

Hi,
I would like to do some experiment with u-boot.
How do I flash it?

[Vonger]

Very easy.

First, make a writable uboot section(update VOCORE.dts, remove read-only in uboot section, compile and flash to VoCore)
Then, use mtd -e uboot write ubootimage.bin uboot

But if you do not have skill recover the uboot, I do not recommend you do this. Once uboot broken, there is no easy way to recover.
My way is remove flash from VoCore and flash the flash by other hardware.

[noblepepper]

This is inherently dangerous, you can easily brick the VoCore. If you load a non-functional uboot or there are power problems during the flash you have a brick. I made sure I could load the flash chip directly before I played with the u-boot partition.

Here is some info on how to do this: DANGEROUS STUFF

You may want to check out my revisions of the stock uboot.

[Ton]

Hi noblepepper,

I am going to try your dangerous stuff on my bricked vocore. I will use a raspberry instead of the arduino you used.
Which file contains the binary data that has to be flashed into the chip?
There are a couple of files in the /bin/ramips directory, I guess one of them?

[qiqiji]

noblepepper‘s DANGEROUS STUFF i have done tons of times with no problem

[noblepepper]

For the uboot I modified use this file

For the original that came on the VoCore use this file


I have found that if you don't hold reset low sometimes the flashing operation is corrupted so I hold it low when I write the flash directly

[ad7zj]

Unfortunately the link to noblepepper's wiki is dead - anyone have an alternate source? I want to backup my flash image and then re-flash his latest uboot build to try.

[ad7zj]

Alright well I was able to get noblepepper's uboot flashed on and it works - and now I can boot the latest builds of openwrt! One question, maybe vonger knows - when I tried to copy uboot into mtd, it failed - I guess the mtd is locked? How to unlock it?

Code: Select all

root@OpenWrt:/tmp# mtd -e uboot write uboot.img uboot
Could not get MTD device info from uboot
Can't open device for writing!


Well to work around this, I used uboot itself to flash the new uboot image, as is described in "Fix Bricked Vocore" here https://vocore.io/v1.html except instead of erase linux, and cp.linux, I use erase uboot and cp.uboot.