Thread: Garmin 265w boot loop, logo, white screen, 3+ years later

Do you think the code for ergn;xrgn in boot.bin somehow uses/requires healthy region 41 to accomplish the erases/writes? I do know the epprom chips regions 14,15,48,91 are writeable with updater.exe successful but same regions errors with ergn;xrgn. But updater.exe us not able to write to regions 16, 31, 41.

So my final verdict: ergn;xrgn always errors out on any region. Updater.exe erases/writes some regions but not others. Why?

Originally Posted by flagmax

Do you think the code for ergn;xrgn in boot.bin somehow uses/requires healthy region 41 to accomplish the erases/writes?

Both boot.bin and bootloader simply don't parse data in region 41 (unlike fw_all.bin), so their behavior is not affected by region 41.

Originally Posted by flagmax

I do know the epprom chips regions 14,15,48,91 are writeable with updater.exe successful but same regions errors with erg;xrgn. But updater.exe us not able to write to regions 16, 31, 41.

This is because writing region 41 (and others) over USB is disabled (in the software, not hardware) in boot.bin and bootloader.

Originally Posted by flagmax

So my final verdict: ergn;xrgn always errors out on any region. Updater.exe erases/writes some regions but not others. Why?

You should clearly understand which piece of software is working in each case.
When you're using update.txt, ldr.bin is working. But it's not implemented in bootloader.
When you're flashing RGN file, things are more complicated.
When the device is in pre-boot mode, bootloader is working initially.
But then you can flash RGN file with boot.bin, and boot.bin will be executed, and receive/flash the rest of the regions.
If you flash RGN file without boot.bin, bootloader will receive/flash the rest of the regions.

Bootloader and boot.bin have a number of regions not writable over USB (software limitation, including region 41).
Boot.bin has a number of regions not writable over update.txt (software limitation, usually not including region 41).

In your particular case boot.bin can't write regions at all (over USB and by update.txt), but bootloader can write regions.
I think this is caused by the difference in the flashing algorithms and partially broken hardware.