OpenGD77

After installation of GD-77_V4.2.6.sgl I cannot enter into firmware update mode (SK1 +SK2 + turn on). Radio blinks 4 times with a green diode and starts normally as usual.

Help please with any idea how to fix it?

That is not a version number of the OpenGD77 firmware, its an official firmware version.

Under some conditions, it appears that the official firmware deliberately prevents people upgrading to the OpenGD77 or other official firmware version.

We have no idea whether this is by-design by Radioddity or a bug in their firmware.

If the official firmware has cleared the update section of the ROM, the only way to update is to connect a hardware programmer to the PCB to installed a "modified" bootloader

We suddenly seem to have several posts from people who have the same problem.

So I'm trying to understand why this has happened.


Can you tell me why you installed the official firmware.

Did previously have the OpenGD77 firmware installed and then need some feature like SMS that is not available in the OpenGD77, so you installed the official firmware ?

Or did you think it was necessary to install the latest official firmware to use the latest OpenGD77 firmware ?

Thanks

Roger

VK3KYY

Hi,

And which tool did you used to flash this SGL ?.


Cheers.
---
Daniel

VK3KYY wrote: ↑

Tue Jul 20, 2021 7:13 am

We suddenly seem to have several posts from people who have the same problem.

So I'm trying to understand why this has happened.


Can you tell me why you installed the official firmware.

Did previously have the OpenGD77 firmware installed and then need some feature like SMS that is not available in the OpenGD77, so you installed the official firmware ?

Because of a wrong understanding of this text below.

To use the OpenGD77 firmware with DMR functionality, must manually download and unzip the official "Firmware and software" package and extract the GD-77_V4.3.6.sgl file, so that the Firmware loader can merge the OpenGD77 firmware with the codec from the official firmware

Poor English knowledge sometimes hurts.

I thought that zip from the official site (HAM EDITION) is an open firmware released in cooperation with the producer and I have to upgrade every upper version.

OK.

I will need to add a note that the official firmware should NOT be installed. It is only used for "patching", which is the process off adding parts of the official into the OpenGD77 firmware

anyone help, i have a friend that has this very problem having installed official fw v4.3.6 and can no longer update to opengd77 !! has anybody found a workaround, something simple ??
is it possible to hex edit the cpu rom or is that the wrong rom ?
any other details greatly appreciated
gd77 two years old

Hi,

g1euq wrote: ↑

Wed Jan 19, 2022 1:54 pm

anyone help, i have a friend that has this very problem having installed official fw v4.3.6 and can no longer update to opengd77 !! has anybody found a workaround, something simple ??
is it possible to hex edit the cpu rom or is that the wrong rom ?
any other details greatly appreciated
gd77 two years old

I'm afraid your friend "killed" the dumb protection of the bootloader.
Some bytes are used in this protection system, and it's not uncommon that the official firmware erase them, like doing "factory reset".

If this did happened, there is still a solution, using a J-Link programmer, flashing a bootloader that Roger modified. In the end, your friend will be able to flash the OpenGD77 using the standard method (SK1 + SK2 + power on).

Cheers.
---
Daniel

Thanks Daniel, do you have any details on how to get a J-link and how it's all hooked up etc and how difficult the operation is ??

g1euq wrote: ↑

Wed Jan 19, 2022 10:09 pm

Thanks Daniel, do you have any details on how to get a J-link and how it's all hooked up etc and how difficult the operation is ??

Its not that difficult to do.

You have to open the radio, which involves removing a few screws in the battery compartment, and then also unscrewing the retaining rings in the volume control and the antenna connector.

The front of the radio then separates from the back of the radio, and you have to unclip the ribbon cable to the front panel / display

When the radio is in 2 halfs, the back of the main PCB is exposed and there are 4 programming pads that are clearly labelled.

You have to connect a JLink debugger to those 4 pads, and then reprogram a patched version of the bootloader into the radio which does not have the flawed copy protection, which is currently causing the problem you are experiencing


You will however need something like a JLink, programmer dongle connect to those pads and upload the bootloader

If you are a member of a local radio club you could ask around to see if anyone has a JLink, to save having to spend £15 to buy an unnofficial JLink from China. A Jlink Edu, or JLink Edu mini also work.

Any ARM processor / debugger which supports NXP/Freescale MK22 would also work, but I've only had experience using the JLink programmer dongles