2020–09–08:
PinePhone multi-boot finishing touches / modem improvements
So I dealt with a few of the „annoying details“ from the last post, and
created a repository
for my build scripts and overrides for each distro.
The last thing to do prior to final testing is to add support for selecting
dtb for PP 1.1 or 1.2 automatically.
Modem power manager
I've also improved my modem power manager a bit, and added support for fast
poweroff mode that's available in the newer modem firmwares. (I believe
it's those firmware that are in Braveheart and onwards.) Modem can now be
powered off in ~2 seconds.
I've also fixed issues with RDY not being received. Looks like
one of the persistent configuration options makes the modem not send RDY.
I just poll for the successfull empty AT command, as a way to
detect when the modem is ready, and that seems to be more reliable.
All these changes are avialable in my 5.8 and 5.9 kernel branches.