Added support for ROMFS scripts

[tridge]

This allows for scripts to be embedded in ROMFS, which removes the dependency on a microSD card for flight critical scripts.
The PR is WIP as the code to load the lua script in AP_Scripting is just a placeholder ready for @WickedShell
files are embedded from two places:

• scripts/ directory at top level of build for SITL
• ROMFS/ directory inside hwdef directory for ChibiOS builds

[rmackay9]

This is very cool. This should remove reliance on the sometimes unreliable SD Cards and also make it possible to embed a script right into the firmware right? Will that be done using apjtools or something similar?

[tridge]

This should remove reliance on the sometimes unreliable SD Cards and also make it possible to embed a script right into the firmware right?

that is right

Will that be done using apjtools or something similar?

at the moment I've set it up so you put the lua scripts in the hwdef directory. For example, if you want CubeBlack to have a myhello.lua you would do:

• mkdir -p libraries/AP_HAL_ChibiOS/hwdef/CubeBlack/ROMFS/scripts
• cp myhello.lua libraries/AP_HAL_ChibiOS/hwdef/CubeBlack/ROMFS/scripts/

it will then put all files in that ROMFS directory into ROMFS where lua scripting engine will load them.
We can certainly add other mechanisms, possibly including apjtool, but for now I'm targeting this at users who want to do their own custom builds. Usually a commercial user will create a custom build using the include mechanism in hwdef.dat to create something derived from a base build, and put a defaults.parm in the directory along with any scripts they want.

[tridge]

replaced by #13793, closing