I recently found my G2 (and G1!) buried in storage. I'd forgotten how much I enjoyed using them, especially the G2. I did the root thing, installing TWRP and a KitKat-based ROM, but it is terribly slow, not least of which for its reported 384M usable RAM.
I like to think I've got a pretty good idea as to how Android devices (generally) boot up, and was thinking I've got a fair amount of practice under my belt building my own Linux kernels, and how I'd really like a Raspberry Pi (or variant), but this device already has everything I'd need for a "SBC"-style device.
If I could slap Das U-Boot on there, I think it'd be pretty easy to (try to) boot a Linux kernel and shell and then figure out laboriously what to do for hardware drivers. (For that matter, what's the G2's capability re: USB OTG?) If it's a matter of making actual changes to HBOOT to tell it to load something other than Android (or kernel followed by Android), I'd be fine with researching that and then doing the laborious building an optimized kernel and drivers.
I could also be talking out my ass and have not, in fact, really understood the Android booting process. But I need a project and it would be really cool if I could work on this, I just don't really know where to look beyond what I've read. I did read one sequence where somebody reported on how they actually did a dual-boot Debian/Android setup (literal dual-boot, not a Debian chroot, which involved him modding the boot image for his LG Optimus). I haven't had time to follow through with it to be sure I can apply any of his findings to HBOOT, but I suppose that might be the best place to start.
One other thing -- if I modify HBOOT and break something, is that a brick, or can I arbitrarily swap out boot images even if they don't work? Or, more directly, will I have a means to re-burn the original image even if I were to completely wipe it? Will fastboot or adb recognize the device and be able to communicate with its filesystem? Not that I'm worried too much about bricking it, but it'd be nice to minimize that chance before I just bite the bullet and try another boot image and cross my fingers.