The upstart kernel files are model specific, you need D35 version (M0t0r0la MTP-3xxx), the latest avaible version is factory upstart kernel-1.24.15.bin
I have tried with several kernel-starts including the one you have mentioned but I always get the same error, or even in other cases the computer does not even start up.
I think the error code HwID=4095 indicates that the radio does not have a valid configuration block. Even after booting probe with MTFlasher to write a .bin image but due to this error it seems that MTFlasher does not know how to map the memory or what permissions to use to write.
That’s why any attempt to flash ends in continuous errors.
I have read that some newer kernels reject any flash writing that does not come from the official AIS (digital signature).
To flash correctly, you need to return to a “blank flash” state or use an old kernel that ignores HWID but I have already tried with all of them after extracting them from the rpk.
Let me save you some time: there is nothing you can do to recover this radio in a straightforward manner. Yes, of course, it can be recovered with “special” firmware files and procedures. However, those files and instructions are not publicly available.
I’ve been looking for information, and they mention the need for a special factory kernel, which isn’t publicly available. I asked if anyone happened to have the file.
It seems that the kernels I mentioned don’t check the HwID and allow writing the entire radio. But if they’re not accessible, there’s nothing I can do.