Help recovering bricked rt-ac56u

hello community ! Smile

As i wanted to join the ARM world (i already have an rt-n16 and rt-n66u - mipsel and almost eol) i've bought a bricked rt-ac56u hoping to revive it.

I've connected a serial console and the output is somehow encouraging but I've failed to make any ip connectivity.

What do you suggest I do next?

thanks in advance for any help !

cfe debug below

Summary

boot_option=2
Decompressing...decompressLZMA: res=6
done

CFE version 2012.02.18 (r312294) based on BBP 1.0.37 for BCM95301X (32bit,SP,)
Build Date: Tue Jul 3 20:57:05 PDT 2012 (hwnbuild@xl-sj1-04)
Copyright (C) 2000-2008 Broadcom Corporation.

Init Arena
Init Devs.
Boot partition size = 262144(0x40000)
spiflash: found no supported devices
spiflash: found no supported devices
spiflash: found no supported devices
boot_option=2
otp_size: 0xbc
find_nvram: no nvram found
boot_option=2
otp_size: 0xbc
find_nvram: no nvram found
boot_option=2
otp_size: 0xbc
find_nvram: no nvram found
boot_option=2
otp_size: 0xbc
find_nvram: no nvram found
CPU type 0x0: 800MHz
Tot mem: 131072 KBytes

CFE mem: 0x00700000 - 0x007B0D68 (724328)
Data: 0x007496FC - 0x00749AD8 (988)
BSS: 0x00749AE8 - 0x0074AD68 (4736)
Heap: 0x0074AD68 - 0x007AED68 (409600)
Stack: 0x007AED68 - 0x007B0D68 (8192)
Text: 0x00700000 - 0x0074114C (266572)

Committing NVRAM...nvram_commit: Failed No valid nvram
done
flash0.0: Device not found
Loader:raw Filesys:tftp Dev:(null) File:flash0.os: Options:(null)
Loading: Failed.
Could not load flash0.os:: Network is down
CFE>
CFE> help
Available commands:

et Broadcom Ethernet utility.
show clocks Show current values of the clocks.
nvram NVRAM utility.
reboot Reboot.
flash Update a flash memory device
batch Load a batch file into memory and execute it
go Verify and boot OS image.
boot Load an executable file into memory and execute it
load Load an executable file into memory without executing it
save Save a region of memory to a remote file via TFTP
ping Ping a remote IP host.
arp Display or modify the ARP Table
ifconfig Configure the Ethernet interface
help Obtain help for CFE commands

For more information about a command, enter 'help command-name'
*** command status = 0
CFE> show clocks
Current clocks: 800/400/400/100 Mhz.
*** command status = 0
CFE> nvram show
pmon_ver=CFE 2012.02.18 (r312294)
size: 54 bytes (32714 left)
*** command status = 0
CFE> et -i=eth0 up
*** command status = -6
CFE> ifconfig eth0 -addr=192.168.1.1 -mask=255.255.255.0
Could not activate network interface 'eth0': Error
*** command status = -1
CFE> ping 192.168.1.1
Could not transmit echo request
192.168.1.1 (192.168.1.1): 0 packets sent, 0 received
*** command status = 1
CFE> show devices
Invalid command: "devices"
Available "show" commands: clocks

*** command status = -1
CFE> ifconfig
Network interface has not been configured
*** command status = 0

nvram erase && reboot. Upon rebooting it should either recover to whatever existing image is flashed or you can reboot into the same console and start the tftpd to flash another firmware.

no luck :frowning:

Summary

CFE> nvram erase
*** command status = -6
CFE> reboot
boot_option=2
Decompressing...decompressLZMA: res=6
done

CFE version 2012.02.18 (r312294) based on BBP 1.0.37 for BCM95301X (32bit,SP,)
Build Date: Tue Jul 3 20:57:05 PDT 2012 (hwnbuild@xl-sj1-04)
Copyright (C) 2000-2008 Broadcom Corporation.

Init Arena
Init Devs.
Boot partition size = 262144(0x40000)
spiflash: found no supported devices
spiflash: found no supported devices
spiflash: found no supported devices
boot_option=2
otp_size: 0xbc
find_nvram: no nvram found
boot_option=2
otp_size: 0xbc
find_nvram: no nvram found
boot_option=2
otp_size: 0xbc
find_nvram: no nvram found
boot_option=2
otp_size: 0xbc
find_nvram: no nvram found
CPU type 0x0: 800MHz
Tot mem: 131072 KBytes

CFE mem: 0x00700000 - 0x007B0D68 (724328)
Data: 0x007496FC - 0x00749AD8 (988)
BSS: 0x00749AE8 - 0x0074AD68 (4736)
Heap: 0x0074AD68 - 0x007AED68 (409600)
Stack: 0x007AED68 - 0x007B0D68 (8192)
Text: 0x00700000 - 0x0074114C (266572)

Committing NVRAM...nvram_commit: Failed No valid nvram
done
flash0.0: Device not found
Loader:raw Filesys:tftp Dev:(null) File:flash0.os: Options:(null)
Loading: Failed.
Could not load flash0.os:: Network is down
CFE>

If the bootloader is trashed, you will need a JTAG cable.

Do you know how to connect jtag to rt-ac56u?
Will an rpi with flashrom work?