RTEMS ITRON 3.0 API User's Guide
The Task Control Block (TCB) is a defined data structure which contains all the information that is pertinent to the execution of a task. During system initialization, implementation reserves a TCB for each task configured. A TCB is allocated upon creation of the task and is returned to the TCB free list upon deletion of the task.
The TCB's elements are modified as a result of system calls made by the application in response to external and internal stimuli. The TCB contains a task's name, ID, current priority, current and starting states, TCB user extension pointer, scheduling control structures, as well as data required by a blocked task.
A task's context is stored in the TCB when a task switch occurs. When the task regains control of the processor, its context is restored from the TCB. When a task is restarted, the initial state of the task is restored from the starting context area in the task's TCB.
RTEMS ITRON 3.0 API User's Guide
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