scripts/dev-needs.sh

Source file repositories/reference/linux-study-clean/scripts/dev-needs.sh

File Facts

System
Linux kernel
Corpus path
scripts/dev-needs.sh
Extension
.sh
Size
6219 bytes
Lines
316
Domain
Support Tooling And Documentation
Bucket
scripts
Inferred role
Support Tooling And Documentation: scripts
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

function help() {
	cat << EOF
Usage: $(basename $0) [-c|-d|-m|-f] [filter options] <list of devices>

This script needs to be run on the target device once it has booted to a
shell.

The script takes as input a list of one or more device directories under
/sys/devices and then lists the probe dependency chain (suppliers and
parents) of these devices. It does a breadth first search of the dependency
chain, so the last entry in the output is close to the root of the
dependency chain.

By default it lists the full path to the devices under /sys/devices.

It also takes an optional modifier flag as the first parameter to change
what information is listed in the output. If the requested information is
not available, the device name is printed.

  -c	lists the compatible string of the dependencies
  -d	lists the driver name of the dependencies that have probed
  -m	lists the module name of the dependencies that have a module
  -f	list the firmware node path of the dependencies
  -g	list the dependencies as edges and nodes for graphviz
  -t	list the dependencies as edges for tsort

The filter options provide a way to filter out some dependencies:
  --allow-no-driver	By default dependencies that don't have a driver
			attached are ignored. This is to avoid following
			device links to "class" devices that are created
			when the consumer probes (as in, not a probe
			dependency). If you want to follow these links
			anyway, use this flag.

  --exclude-devlinks	Don't follow device links when tracking probe
			dependencies.

  --exclude-parents	Don't follow parent devices when tracking probe
			dependencies.

EOF
}

function dev_to_detail() {
	local i=0
	while [ $i -lt ${#OUT_LIST[@]} ]
	do
		local C=${OUT_LIST[i]}
		local S=${OUT_LIST[i+1]}
		local D="'$(detail_chosen $C $S)'"
		if [ ! -z "$D" ]
		then
			# This weirdness is needed to work with toybox when
			# using the -t option.
			printf '%05u\t%s\n' ${i} "$D" | tr -d \'
		fi
		i=$((i+2))
	done
}

function already_seen() {
	local i=0
	while [ $i -lt ${#OUT_LIST[@]} ]
	do
		if [ "$1" = "${OUT_LIST[$i]}" ]
		then
			# if-statement treats 0 (no-error) as true
			return 0
		fi
		i=$(($i+2))

Annotation

Implementation Notes