CONTRIBUTING.md

Before sending a patch, it's helpful to consider some of the criteria that patches are evaluated against:

• Use local for limiting scope of variables in functions
• Do not hard-code /boot, use $output_dir
• Only write to $work_dir, and anything you want copied to $output_dir should be added to $additional_files. For example, a function should do something like this to create a file and add it to the final destination / output directory:

foo() {
	local thing="bar.img"
	# create some new file
	echo "bazz" > "$work_dir/$thing"

	# copy the new file to the destination directory
	additional_files="$additional_files $thing"
}

There are lots of examples in the codebase where we try to stick to these things, and if you find examples of us not doing it then that is a bug :)

Developers guide

Installing files into the output directory

Functions should not install files directly into the output directory (e.g. using copy.) Instead, paths to files in the work directory should be appended to $additional_files.

If functions call copy on their own, it's possible that boot-deploy might fail at a later point, leaving potentially broken cruft in the output directory. For example, the output directory may run out of free space later, or some other runtime failure may occur. By adding files to $additional_files, everything will be copied at the end of the program, and the free space check will be more reliable.

Variable naming

Global variables should be named with lower casing, beginning with a letter. The use of underscores, e.g. to separate words in a variable name, is allowed. An example of a global variable name is: output_dir.

boot-deploy is implemented in POSIX sh, except for the use of the local keyword to give variables local scoping where appropriate. local should be used at all times when declaring variables that should only exist within a function. Function variable names should also begin with a single underscore, in order to not conflict with any global variables. An example of a function variable name is: _uboot_image_files.

Testing

Contributions should pass .ci/run.sh without errors/warnings.