Tribblix: manual page: picld.8

PICLD(8) Maintenance Commands and Procedures PICLD(8)

NAME

picld - PICL daemon

SYNOPSIS

/usr/lib/picl/picld

DESCRIPTION

The Platform Information and Control Library (PICL) provides a
mechanism to publish platform-specific information for clients to
access in a platform-independent way. picld maintains and controls
access to the PICL information from clients and plug-in modules. The
daemon is started in both single-user and multi-user boot mode.

Upon startup, the PICL daemon loads and initializes the plug-in
modules. These modules use the libpicltree(3PICLTREE) interface to
create nodes and properties in the PICL tree to publish platform
configuration information. After the plug-in modules are initialized,
the daemon opens the PICL daemon door to service client requests to
access information in the PICL tree.

PICL Tree

The PICL tree is the repository of all the nodes and properties
created by the plug-in modules to represent the platform
configuration. Every node in the PICL tree is an instance of a well-
defined PICL class. The name of the base PICL class is picl, which
defines a basic set of properties that all nodes in the tree must
possess. Two of those properties are name and _class, where name
contains the name of the node, and the _class contains the PICL class
name of the node. Certain nodes in the PICL tree have well-known
names. For example, the name of the root node of the PICL tree is /
and the name of the root node of the sub-tree containing platform
device nodes is platform.

PICL plug-in Modules
The PICL plug-in modules are shared objects that publish platform-
specific data in the PICL tree. They are located in well-known
directories so that the daemon can locate and load them.

Plug-in modules are located in one of the following plug-in
directories depending on the platform-specific nature of the data
that they collect and publish:

/usr/platform/`uname -i`/lib/picl/plugins
/usr/platform/`uname -m`/lib/picl/plugins

A plug-in module can specify its dependency on another plug-in module
using the -l or -R linker option. The plug-ins are loaded by the
daemon using dlopen(3C) according to the specified dependencies. Each
plug-in module must define a .init section, which is executed when
the plug-in module is loaded, to register themselves with the daemon.
See picld_plugin_register(3PICLTREE) for additional information on
plug-in registration.

The plug-in modules use the libpicltree(3PICLTREE) interface to
publish nodes and properties in the PICL tree so that clients can
access them.

When the PICL daemon invokes the initialization routine of the plug-
in module, the plug-in collects the platform information and creates
nodes and/or properties to represent the configuration in the PICL
tree. A plug-in can create additional threads to monitor the platform
configuration and update the PICL tree with any changes. This enables
a PICL plug-in to operate as a daemon within the PICL framework.

An environmental monitor is an example of a plug-in module that uses
a thread to monitor the temperatures and fan speeds of the platform,
then publishes the environmental information in the PICL tree so
clients can access them.

Clients use the libpicl(3PICL) interface to send requests to picld
for accessing the PICL tree.

EXIT STATUS

picld does not return an exit status.

FILES

/var/run/picld_door
PICL daemon door

/usr/lib/picl/picld
PICL daemon

NOTES

The picld service is managed by the service management facility,
smf(7), under the service identifier:

svc:/system/picl

Administrative actions on this service, such as enabling, disabling,
or requesting restart, can be performed using svcadm(8). The
service's status can be queried using the svcs(1) command.

May 16, 2020 PICLD(8)