This could previously only be done with 'devinfo global'. While
this is still possible this adds a more direct access via the
globalvar command. This variant also adds a '*' in front of
the variable if the corresponding non volatile variable exists.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This adds (back) support for non volatile variables. Non volatile
variables are variables which are stored in the environment over
reboot. They are used in the same way as the global variables, but
with a 'nv' command and device. The variables are stored under
/env/nv/, one variable per file. Adding a nv variable automatically
adds a global variable with the same name. Changing a nv variable
also changes the same global variable, but not the other way round.
This allows for example to configure the username as:
nv user=sha; saveenv
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Calling globalvar_add_simple() and setting a value is more than common.
Add a parameter for the initial value.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This implements global shell variable support. This is done by registering
a new device named 'global', so global variables are just plain device
parameters.
Global variables are useful for storing the global state in the environment.
Currently we do this by sourcing scripts instead of executing them which is
quite limiting.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>