geez louise. finally unlocked the dumb bootloader by using a partedmagic bootable linux usb to just run the linux fastboot.
problem seems to be windows 10 can't (in my case, or on rm's laptop) see the connected device when it's in fastboot mode. it is super fun to mess with esoteric USB drivers to no avail, i assure you.
ok, what is next. need to replace the recovery partition somehow, then find a rom.
@alyx I think win10 is intentionally broken for booting anything else. It's really irritating. For my own laptop, you have to turn UEFI off in the BIOS before it'll even acknowledge anything but the Windows boot partition. 👢 💫 💻
@alyx Ah. That makes sense. Android got some weird "lockdown" stuff under the radar a few years ago, and IIRC that was one of them. Yay for Linux, though!
@TheOtherAMF mm. my problem isn't about booting into an OS, but that Win10 doesn't want to see this android phone when the phone's in fastboot mode. therefore i can't flash it or do anything else useful from windows.
linux to the rescue, it seems.
my early i7 (LGA-1366) mobo is from 2010? so no UEFI to worry about. i hope it's not too awful whenever i "upgrade" to a more modern system.