Most of the guides that I have found are for non HTC phones. I have a few links for you to check out. From what I have read, they are mostly framework-res.apk and android.policy.jar edits.
I have extracted the classes.dex out of the jar and tried to wade my way through all of the .smali files. It looks as if the GlobalActions.smali points to either GlobalActions3 or GlobalActions4.smali for reboot options.
The guides also point to certain edits which need to be made to the framework-res.apk. Mainly strings.xml. They say to then recompile, then decompile the new framework-res.apk and lookup certain hex values in public.xml.I thought I had it figured out, but then I saw that some of the hex codes were 4xxxxxx hex codes, which points to framework-HTC-res.apk. That's kindof where I got stuck because I could not get that apk to successfully decompile.
Looking at the GlobalActions.smali I saw references to com.HTC.resources, so I kinda knew this was to be expected. I seem to be having trouble getting the necessary framework installed through apktool to successfully decompile.
Additionally, I have taken apart quite a few Roms frameworks (Roms that aren't using Sense 5 toolbox or exposed mods) to try to decipher how they applied the necessary changes, yet they are all so different. Some look to have used arrays, others strings. I know the arrays are probably for multilingual options.
Links coming as soon as I get to my pc.
Click button below for links:
When reading the hex values in the files, the chart below should point you in the right direction:
I too am trying to learn how to do all of this. Please let me know if you figure anything out. It seems to be who you know around here that directly reflects what you know.