Here's an example of a project which starts custom executables directly from a RAM disk image (/boot/initrd). It's certanly not the earliest place possible, but at least it happens before the root partition is mounted, so this code runs before anything located on the root partition. It's as early as you can get without writing kernel code.
The I2C driver can ...
That is never going to work. VGA doesn't carry the same signal as HDMI. You need an active adapter to convert HDMI to VGA, it won't ever work in reverse like you're asking. – Dougie Aug 15 at 0:12
You would be better off with a micro-HMDI-to-HDMI-adapter and a standard HDMI cable. – Pete Hooper Aug 15 at 15:44
Although this topic is not new, the autostart problem resurfaced newly again. The fact that Conky was not auto-starting anymore, made me aware of this new issue.
After some unsuccessful efforts by using the latest hints that I found on the web, I tried:
by adding a symlink to a shell-script (see image below) .