[SOLVED] U-Boot for DGN3500 damaged after unbrick

Hello all,
I had lede version 17.01.5 installed on my netgear DGN3500, and I use it with an LTE usb dongle ZTE MF833T.
The dongle use cdc-ether module to connect on internet.
I tried to upgrade lede to openwrt 18.06, it works fine but when I enable the USB dongle the modem crash and restart, then I tried to downgrade already to lede 17.01.05 but the modem BRICKED.
I connected on the modem with serial port to unbrick it, and I was able to restore the modem, but unfortunately I damaged the u-boot.
When the modem start it fail the KFS integrity and swap in recovery mode:

Will check KFS integrality. read KFS first
EEPROM @0x0 read: addr 0x80500000  off 0x50000  count 16384000
..........................................................................................................................................................................................................................................................done
sercomm_trap will go to dl_mode, because un-assigned MAC
sercomm_trap will go to as_mode.
--- enter ASMOD ---

FLASH BASE: 0x0, FLASH SIZE: 0x1000000
setenv kernel_addr=0x50000

getPIDfromFlash: YP5723
asmod_start: getPIDfromFlash ok...
@@@  enter ASMOD mode
checksum bad
checksum bad
checksum bad
checksum bad
asmod_handler()


asmod_handler()


asmod_handler()

if I type ctrl+c in serial console it unlock and continue to load the firmware:

asmod_handler()
Abort
NetLoop Fail
## Application terminated, rc = 0x0
## Booting image at 00050000 ...
*** eeprom_read
*** eeprom_read

addr = 50000
CFG_LOAD_ADDR = 80100000
.......................addr = 80500000

   Image Name:   MIPS LEDE Linux-4.4.140
   Created:      2018-07-13  19:25:14 UTC
   Image Type:   MIPS Linux Kernel Image (lzma compressed)
   Data Size:    1571634 Bytes =  1.5 MB
   Load Address: 80002000
   Entry Point:  80002000
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK

 **** do_bootm_linux

could you help me to find an u-boot version compatible with my modem?
this is the original uboot:
DGN3500 U-Boot

I tried to reinstall also the stock firmware but the behaviour is the same.
thanks
Ivan

I identified another issue:
the ath9k wireless driver isn't able to read the mac addredd from uboot-dev partition and the wireless module doesn't work:

[   14.894313] PCI: Enabling device 0000:00:0e.0 (0000 -> 0002)
[   14.906705] ath: phy0: Bad EEPROM checksum 0xa411
[   14.910006] ath: phy0: Unable to initialize hardware; initialization status: -22
[   14.917357] ath9k 0000:00:0e.0: Failed to initialize device
[   14.922955] ath9k: probe of 0000:00:0e.0 failed with error -22

Hello,
I received the bootloader from a user that have the same modem.
these are my boot loader partitions:

dev:    size   erasesize  name
mtd0: 00010000 00010000 "uboot"
mtd1: 00010000 00010000 "uboot-env"
mtd2: 00010000 00010000 "calibration"

I update the uboot, ubot-env and calibration (I modified the bin files of uboot-dev and calibration inserting my personal data device (Serial Number, PIN and ethernet address)), but unfortunately after restore the behaviour is the same.
On boot i receive this output:

OM VER: 1.1.3
CFG 05


U-Boot 1.1.5-2.4 (Oct  4 2010 - 11:54:53)

**checkboard **
Boot from SPI
AR9 BOARD
CLOCK CPU 333M RAM 166M
DRAM:  64 MB
spi_init_f finsihed
	 SFLASH_BAUDRATE = 30000000
	 CONFIG_SPI_FLASH_SLOW_READ yes

 relocate_code start
 relocate_code finish.
Flash: 16 MB
  bi_flashstart=00000000
  bi_flashsize=01000000
  bi_flashoffset=00000000
spi_init_f finsihed
	 SFLASH_BAUDRATE = 30000000
	 CONFIG_SPI_FLASH_SLOW_READ yes
`**_*** Warning - bad CRC, using default environment_**`

In:    serial
Out:   serial
Err:   serial
Net:   
*** amazon_s_sw_chip_init

switch chip id=0000ffff
init 8366 rb
 -The DATA=0x0

The DATA=0x1C

The DATA=0xC961

The DATA=0x1140

smi_init = 0
initChip verid = 0x3
rtl8366rb_initChip= 0
The 0x0=0x830    0

The 0x509=0x5937    0

rtl8368s_setAsicMacForceLink = 0   
rtl8366rb_setLedMode(2, null)=0
amazon_s Switch
board_init_r:
	 PID=YP5723
	 ethaddr=00:e0:92:01:01:7d
	 `**_serialnumber=<null>_**`
	 `_**pin=<null>**_`

Type "run flash_nfs" to mount root filesystem over NFS

Hit any key to stop autoboot:  3  2  1  0

As you can see I receive the warning:

*** Warning - bad CRC, using default environment

and the serial number and PIN are empty:

board_init_r:
	 PID=YP5723
	 ethaddr=00:e0:92:01:01:7d
	 serialnumber=<null>
	 pin=<null>

can someone help me to understand how to restore the bootloader?
thanks Ivan

To solve the crc error you need to do saveenv
(Caused by empty uboot config)

thanks,
with saveenv the CRC Warning disappear, but my problem persists.
thanks
Ivan

I solved the problem with u-boot, I set the correct etheret address, serial number and PIN of my modem and now the modem start correctly, but unfortunately the wireless card doesn't start because on startup I receive this error:

[ 14.594703] PCI: Enabling device 0000:00:0e.0 (0000 -> 0002)
[ 14.608063] ath: phy0: Bad EEPROM checksum 0xa411
[ 14.611376] ath: phy0: Unable to initialize hardware; initialization status: -22
[ 14.618714] ath9k 0000:00:0e.0: Failed to initialize device
[ 14.624310] ath9k: probe of 0000:00:0e.0 failed with error -22

I believed tha this error was releated to problem on u-boot, but it persist.
I found this article: https://lists.openwrt.org/pipermail/openwrt-devel/2017-February/005926.html
but I had the same lede version before try to upgrade to OpenWRT 18.06 and it worked fine without any issue.

1 Like

I reinstalled the lede firmware and also wireless card works again..

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