putnam
commented
3 weeks ago Update: I found your post here on the GBATemp thread: https://gbatemp.net/threads/internal-modchip-samd21-trinket-m0-gemma-m0-itsybitsy-m0-express-guide-files-support.508068/page-133#post-8564444
Q - I cannot access SWITCHBOOT drive like I used to. Help!
A - Yep. Known problem. Just get to Switchboot Part 2 menu, double-press RESET so red LED is breathing, plug in USB cable, and boot something (cfw / ofw). SWITCHBOOT will pop up.
I used TegraRCMGUI to push Hekate over to the switch in this condition and got it to boot into the OS, and sure enough I got SWITCHBOOT back. That's a relief. I'm now reverting the bootloader back to the v6 edition.
mattytrog
First, thanks for this project. Very handy for the Erista switches.
I have a Gemma M0.
I am trying to downgrade from v9 back to v6, because I always use Hekate, all my tools auto-update by replacing fusee.bin, and I don't want to keep renaming fusee.bin every time it is auto-updated.
I got into UF2 update mode, saw FUSEE as the drive, and I dragged in the old v6 Part 2. This sort of worked; I could get to the v6 boot menu by holding PWR and everything looked OK. I can also manually select a payload here and it boots OK.
But when it tries to cold boot into the payload from initial power on, I get weird behavior where the screen stays black.
I suspected that this was because I have the newer stage 1 bootloader on my Gemma, so I wanted to downgrade. But something seems to have changed in update mode where you no longer get the "SWITCHBOOT" drive first. So I didn't know how I was meant to replace the bootloader anymore.
So, then, stupidly, I dragged the old v6-era stage 1 UF2 file (FUSEE_SUITE_GEMMA.uf2) onto the FUSEE volume. After that the chip is basically bricked. It has one solid red light and one pulsing red light. Tapping the reset button doesn't do anything and no USB volumes mount anymore.
Any suggestions for what I should do next to repair this thing?