E4200 bad flash recovery

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ZeroLabs
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PostPosted: Wed Dec 16, 2020 19:41    Post subject: Reply with quote
Quick question: Is the JTAG header live or do I need to bridge any SMD resistor pads under the metal cover like some other models? The wires I attached are 24ga solid copper from standard CAT-5 cable. Pinpoint tip and a very tiny bit of silver filled flux. Stripped the insulation about 1/8" higher than where it was soldered, then slipped it down the wire until it met close to the PCB. No shorts here. I measure about 1M ohm from 3,5,7,9 to ground.


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PowerPoldi
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PostPosted: Thu Dec 17, 2020 8:57    Post subject: Reply with quote
According to my resarches on the web in spring, I've found no evidence, that you'll need to bridge any resistors. Just solder the wires into the pin-header and connect them to a JTAG-adapter.

However, I've never tested!
ZeroLabs
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PostPosted: Sat Dec 26, 2020 22:20    Post subject: Reply with quote
Altera USB Blaster finally came today. Had to add a /etc/udev rule in order to enable it. Made up some labels for the pinouts. It seems to talk but hangs.
Code:
~$ openocd -f interface/altera-usb-blaster.cfg
Open On-Chip Debugger 0.11.0-rc1+dev-00001-g0dd3b7f-dirty (2020-12-26-10:44)
Licensed under GNU GPL v2
For bug reports, read
   http://openocd.org/doc/doxygen/bugs.html
Info : only one transport option; autoselect 'jtag'
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : usb blaster interface using libftdi
Info : This adapter doesn't support configurable speed
Warn : There are no enabled taps.  AUTO PROBING MIGHT NOT WORK!!
Info : JTAG tap: auto0.tap tap/device found: 0x1471617f (mfg: 0x0bf (Broadcom), part: 0x4716, ver: 0x1)
Warn : AUTO auto0.tap - use "jtag newtap auto0 tap -irlen 32 -expected-id 0x1471617f"
Warn : gdb services need one or more targets defined

Seems to me it found the target. Don't know why it's asking me to define it.

EDIT: Reading the docs a bit more I arrive at
Code:

:~$ openocd -f interface/altera-usb-blaster.cfg -f target/bcm4718.cfg
Open On-Chip Debugger 0.11.0-rc1+dev-00001-g0dd3b7f-dirty (2020-12-26-10:44)
Licensed under GNU GPL v2
For bug reports, read
   http://openocd.org/doc/doxygen/bugs.html
Info : only one transport option; autoselect 'jtag'
Forcing reset_config to none to prevent OpenOCD from pulling SRST after the switch from LV is already performed
switch_lv_to_ejtag
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : usb blaster interface using libftdi
Info : This adapter doesn't support configurable speed
Info : JTAG tap: bcm4718-lv.tap tap/device found: 0x0008c17f (mfg: 0x0bf (Broadcom), part: 0x008c, ver: 0x0)
Info : JTAG tap: bcm4718-lv.tap disabled
Info : JTAG tap: bcm4718.cpu enabled
Info : starting gdb server for bcm4718.cpu on 3333
Info : Listening on port 3333 for gdb connections


So, I've edited MAC and SN in the cfe_e4200_V1.bin I downloaded from https://forum.dd-wrt.com/phpBB2/viewtopic.php?p=889394 using ghex. Took a bit but I learned the last group of numbers at the bottom of the SN/MAC tag is the WPS PIN, which really doesn't matter because you couldn't pay me to use WPS anyway.

Now if I could only get it to do something more than just listen. Like, oh I don't know, respond maybe?

.

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ZeroLabs
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Joined: 08 Apr 2017
Posts: 48
Location: Underground lair

PostPosted: Sat Jan 02, 2021 12:15    Post subject: Reply with quote
kernel-panic69 wrote:
Well, with as much as I have spent on birthday and Christmas presents to myself this year to make up for all of the COVID gloom, no worries! Good luck!


Well, Kernel, with as much time as I have spent beating my head against a wall trying to put together a target config file that would allow me to talk to this thing with JTAG, I give up. DM me your address and I will send you a gift. Else it's dumpster food.

Happy new year anyway!

Z

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ZeroLabs
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Joined: 08 Apr 2017
Posts: 48
Location: Underground lair

PostPosted: Sun Jan 17, 2021 22:10    Post subject: Reply with quote
Okay I'll throw it up for grabs. Anyone want a challenge? I'll send you my e4200 for free. Already has serial header pins and JTAG wires attached. Just DM me an address.

Going once..........
Going twice..........
GONE. Dumpster food.

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