If the procedure above doesn't work we need to go very low level and use the hardware bootloader to load u-boot from the serial line into the RAM, and from there we will run the flash procedure.
This can only be run on Linux.
Boot your PC on your favorite distribution and go into the U-Boot compilation tree (clone it from github if you need to). Then build the kwboot utility :
Code: Select all
charles@darkcix:~/projects$ git clone https://github.com/Excito/U-Boot-B3.git
Cloning into 'U-Boot-B3'...
remote: Counting objects: 8361, done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 8361 (delta 4), reused 3 (delta 3), pack-reused 8354
Receiving objects: 100% (8361/8361), 14.39 MiB | 2.63 MiB/s, done.
Resolving deltas: 100% (2396/2396), done.
Checking connectivity... done.
charles@darkcix:~/projects$ cd U-Boot-B3/
charles@darkcix:~/projects/U-Boot-B3$ make tools/kwboot
cc tools/kwboot.c -o tools/kwboot
charles@darkcix:~/projects/U-Boot-B3$ cd tools/
charles@darkcix:~/projects/U-Boot-B3/tools$ wget -q http://install.excito.org/b3/uboot/beta/uboot-rodeus.zip
charles@darkcix:~/projects/U-Boot-B3/tools$ unzip uboot-rodeus.zip
Archive: uboot-rodeus.zip
creating: install/
inflating: install/u-boot.kwb
For the next step your B3 power plug needs to be removed and the usb key containing the working u-boot version should be plugged (see previous post). I suppose you only have one usb-serial adapter as your screenshots show, the device should be /dev/ttyUSB0. You obviously need write access to it so run the following as root or add your user to the group with sufficient rights on the serial devices.
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charles@darkcix:~/projects/U-Boot-B3/tools$ ./kwboot -b install/u-boot.kwb -p -t -B 115200 /dev/ttyUSB0
Sending boot message. Please reboot the target.../
The last character should spin. Apply power on the B3 and wait for the upload to finish. Then quickly press enter at the "Hit any key to stop autoboot" prompt otherwise your B3 will start the OS.
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Sending boot message. Please reboot the target...-
Sending boot image...
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[Type Ctrl-\ + c to quit]
U-Boot 2013.01.01-b3-rodeus-g53a85c9 (Jan 16 2016 - 01:59:03)
BUBBA|3
SoC: Kirkwood 88F6281_A1
DRAM: 512 MiB
WARNING: Caches not enabled
SF: Detected M25P16 with page size 64 KiB, total 2 MiB
In: serial
Out: serial
Err: serial
Net: egiga0, egiga1
88E1116 Initializing on egiga0 @08 done
88E1116 Initializing on egiga1 @09PHY reset timed out
done
Hit any key to stop autoboot: 0
B3>
The hardest part is done. Run the following commands to flash the device :
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B3> usb start
(Re)start USB...
USB0: USB EHCI 1.00
scanning bus 0 for devices... 3 USB Device(s) found
scanning usb for storage devices... 1 Storage Device(s) found
B3> run usbflash
reading /install/u-boot.kwb
255772 bytes read in 44 ms (5.5 MiB/s)
SF: Detected M25P16 with page size 64 KiB, total 2 MiB
B3>
That should do it. Now reset the board and it should start normally:
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B3> reset
resetting ...
U-Boot 2013.01.01-b3-rodeus-g53a85c9 (Jan 16 2016 - 01:59:03)
BUBBA|3
SoC: Kirkwood 88F6281_A1
DRAM: 512 MiB
WARNING: Caches not enabled
SF: Detected M25P16 with page size 64 KiB, total 2 MiB
In: serial
Out: serial
Err: serial
Net: egiga0, egiga1
88E1116 Initializing on egiga0 @08 done
88E1116 Initializing on egiga1 @09PHY reset timed out
done
Hit any key to stop autoboot: 0
3682680 bytes read in 140 ms (25.1 MiB/s)
## Booting kernel from Legacy Image at 00800000 ...
Image Name: Linux-3.18.24-1
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 3682616 Bytes = 3.5 MiB
Load Address: 00008000
Entry Point: 00008000
Verifying Checksum ... OK
Loading Kernel Image ... OK
OK
Starting kernel ...
[ 0.000000] Booting Linux on physical CPU 0x0
..... bla bla bla linux booting .....
Press Ctrl-\ then c to exit kwboot. That's it you unbricked your b3 using a very cool procedure