2008-06-02 Joel Sherrill <joel.sherrill@oarcorp.com>

	* user/bsp.t, user/init.t: Rework initialization and BSP chapters to
	account for changes to initialization framework.

1 files changed, 196 insertions, 92 deletions

diff --git a/doc/user/init.t b/doc/user/init.t
index 3dc368f9d1..6bfb1fffe8 100644
--- a/doc/user/init.t
+++ b/doc/user/init.t
@@ -10,17 +10,19 @@
 
 @section Introduction
 
-The initialization manager is responsible for
+The Initialization Manager is responsible for
 initiating and shutting down RTEMS.  Initiating RTEMS involves
 creating and starting all configured initialization tasks, and
 for invoking the initialization routine for each user-supplied
 device driver.  In a multiprocessor configuration, this manager
 also initializes the interprocessor communications layer.  The
-directives provided by the initialization manager are:
+directives provided by the Initialization Manager are:
 
 @itemize @bullet
-@item @code{@value{DIRPREFIX}initialize_executive_early} - Initialize RTEMS and do NOT Start Multitasking
-@item @code{@value{DIRPREFIX}initialize_executive_late} - Complete Initialization and Start Multitasking
+@item @code{@value{DIRPREFIX}initialize_data_structures} - Initialize RTEMS Data Structures
+@item @code{@value{DIRPREFIX}initialize_before_drivers} - Perform Initialization Before Device Drivers
+@item @code{@value{DIRPREFIX}initialize_device_drivers} - Initialize Device Drivers
+@item @code{@value{DIRPREFIX}initialize_start_multitasking} - Complete Initialization and Start Multitasking
 @item @code{@value{DIRPREFIX}shutdown_executive} - Shutdown RTEMS
 @end itemize
 
@@ -53,41 +55,40 @@ This transformation typically involves changing priority and
 execution mode.  RTEMS does not automatically delete the
 initialization tasks.
 
-@subsection The System Initialization Task
+@subsection System Initialization
 
-The System Initialization Task is responsible for
-initializing all device drivers.  As a result, this task has a
-higher priority than all other tasks to ensure that no
-application tasks executes until all device drivers are
-initialized.  After device initialization in a single processor
-system, this task will delete itself.
+System Initialization begins with board reset and continues
+through RTEMS initialization, initialization of all device
+drivers, and eventually a context switch to the first user
+task.  Remember, that interrupts are disabled during
+initialization and the @i{initialization thread} is not
+a task in any sense and the user should be very careful
+during initialzation.
 
-The System Initialization Task must have enough stack
-space to successfully execute the initialization routines for
+The BSP must ensure that the there is enough stack
+space reserved for the initialization "thread" to
+successfully execute the initialization routines for
 all device drivers and, in multiprocessor configurations, the
 Multiprocessor Communications Interface Layer initialization
-routine.  The CPU Configuration Table contains a field which
-allows the application or BSP to increase the default amount of
-stack space allocated for this task.
-
-In multiprocessor configurations, the System
-Initialization Task does not delete itself after initializing
-the device drivers.  Instead it transforms itself into the
-Multiprocessing Server which initializes the Multiprocessor
-Communications Interface Layer, verifies multiprocessor system
-consistency, and processes all requests from remote nodes.
+routine.
 
 @subsection The Idle Task
 
 The Idle Task is the lowest priority task in a system
 and executes only when no other task is ready to execute.  This
-task consists of an infinite loop and will be preempted when any
-other task is made ready to execute.
+default implementation of this task consists of an infinite
+loop. RTEMS allows the Idle Task body to be replaced by a CPU
+specific implementation, a BSP specific implementation or an
+application specific implementation.
+
+The Idle Task is preemptible and @b{WILL} be preempted when
+any other task is made ready to execute.  This characteristic is
+critical to the overall behavior of any application.
 
 @subsection Initialization Manager Failure
 
-The @code{@value{DIRPREFIX}ifatal_error_occurred} directive will be called
-from @code{@value{DIRPREFIX}initialize_executive}
+The @code{@value{DIRPREFIX}fatal_error_occurred} directive will
+be invoked from @code{@value{DIRPREFIX}initialize_executive}
 for any of the following reasons:
 
 @itemize @bullet
@@ -118,42 +119,72 @@ initialization sequence.
 @item If any of the user initialization tasks cannot be
 created or started successfully.
 @end itemize
+ 
+A discussion of RTEMS actions when a fatal error occurs 
+may be found @ref{Fatal Error Manager Announcing a Fatal Error}.
+
 
 @section Operations
 
 @subsection Initializing RTEMS
 
-The Initializatiton Manager directives are called by the
-board support package framework as part of its initialization
-sequence.  RTEMS assumes that the board support package
+The Initialization Manager directives are called by the
+Board Support Package framework as part of its initialization
+sequence.  RTEMS assumes that the Board Support Package
 successfully completed its initialization activities.  These
 directives initialize RTEMS by performing the following actions:
 
 @itemize @bullet
 @item Initializing internal RTEMS variables;
 @item Allocating system resources;
-@item Creating and starting the System Initialization Task;
 @item Creating and starting the Idle Task;
+@item Initialize all device drivers;
 @item Creating and starting the user initialization task(s); and
 @item Initiating multitasking.
 @end itemize
 
-This directive MUST be called before any other RTEMS
-directives.  The effect of calling any RTEMS directives before
-@code{@value{DIRPREFIX}initialize_executive_early}
-is unpredictable.  Many of RTEMS actions
-during initialization are based upon the contents of the
-Configuration Table.  For more information regarding the format
-and contents of this table, please refer to the chapter
-Configuring a System.
+The initialization directives MUST be called in the proper
+sequence before any blocking directives may be used.  The services
+in this manager should be invoked just once per application
+and in precisely the following order:
+
+@itemize @bullet
+@item @code{@value{DIRPREFIX}initialize_data_structures}
+@item @code{@value{DIRPREFIX}initialize_before_drivers}
+@item @code{@value{DIRPREFIX}initialize_device_drivers}
+@item @code{@value{DIRPREFIX}initialize_start_multitasking}
+@end itemize
+
+It is recommended that the Board Support Package use the
+provided framework which will invoke these services as 
+part of the executing the function @code{boot_card} in the
+file @code{c/src/lib/libbsp/shared/bootcard.c}.  This
+framework will also assist in allocating memory to the
+RTEMS Workspace and C Program Heap and initializing the
+C Library.
+
+The effect of calling any blocking RTEMS directives before
+@code{@value{DIRPREFIX}initialize_start_multitasking}
+is unpredictable but guaranteed to be bad.  Afer the
+directive @code{@value{DIRPREFIX}initialize_data_structures}
+is invoked, it is permissible to allocate RTEMS objects and
+perform non-blocking operations.  But the user should be
+distinctly aware that multitasking is not available yet
+and they are @b{NOT} executing in a task context.
+
+Many of RTEMS actions during initialization are based upon
+the contents of the Configuration Table.  For more information
+regarding the format and contents of this table, please refer
+to the chapter @ref{Configuring a System}.
 
 The final step in the initialization sequence is the
 initiation of multitasking.  When the scheduler and dispatcher
 are enabled, the highest priority, ready task will be dispatched
-to run.  Control will not be returned to the board support
-package after multitasking is enabled until
-@code{@value{DIRPREFIX}shutdown_executive_late}
-the directive is called.
+to run.  Control will not be returned to the Board Support
+Package after multitasking is enabled until the
+@code{@value{DIRPREFIX}shutdown_executive} directive is called.
+This directive is called as a side-effect of POSIX calls
+including @code{exit}.
 
 @subsection Shutting Down RTEMS
 
@@ -161,26 +192,26 @@ The @code{@value{DIRPREFIX}shutdown_executive} directive is invoked by the
 application to end multitasking and return control to the board
 support package.  The board support package resumes execution at
 the code immediately following the invocation of the
-@code{@value{DIRPREFIX}initialize_executive} directive.
+@code{@value{DIRPREFIX}initialize_start_multitasking} directive.
 
 @section Directives
 
-This section details the initialization manager's
+This section details the Initialization Manager's
 directives.  A subsection is dedicated to each of this manager's
 directives and describes the calling sequence, related
 constants, usage, and status codes.
 
 @page
-@subsection INITIALIZE_EXECUTIVE_EARLY - Initialize RTEMS and do NOT Start Multitasking
+@subsection INITIALIZE_DATA_STRUCTURES - Initialize RTEMS Data Structures
 
-@cindex initialize RTEMS
+@cindex initialize RTEMS data structures
 
 @subheading CALLING SEQUENCE:
 
 @ifset is-C
-@findex rtems_initialize_executive_early
+@findex rtems_initialize_data_structures
 @example
-rtems_interrupt_level rtems_initialize_executive_early(
+void rtems_initialize_data_structures(
   rtems_configuration_table *configuration_table
 );
 @end example
@@ -198,30 +229,119 @@ NONE
 
 @subheading DESCRIPTION:
 
-This directive is called when the board support
-package has completed its initialization to allow RTEMS to
-initialize the application environment based upon the
-information in the Configuration Table, CPU Dependent
-Information Table, User Initialization Tasks Table, Device
-Driver Table, User Extension Table, Multiprocessor Configuration
-Table, and the Multiprocessor Communications Interface (MPCI)
-Table.  This directive returns to the caller after completing
-the basic RTEMS initialization but before multitasking is
-initiated.  The interrupt level in place when the directive is
-invoked is returned to the caller.  This interrupt level should
-be the same one passed to
-@code{@value{DIRPREFIX}initialize_executive_late}.
+This directive is called when the Board Support
+Package has completed its basic initialization and
+allows RTEMS to initialize the application environment based upon the
+information in the Configuration Table, User Initialization
+Tasks Table, Device Driver Table, User Extension Table,
+Multiprocessor Configuration Table, and the Multiprocessor
+Communications Interface (MPCI) Table.  This directive returns
+to the caller after completing the basic RTEMS initialization.
+
+@subheading NOTES:
+
+The Initialization Manager directives must be used in the
+proper sequence and invokved only once in the life of an application.
+
+This directive must be invoked with interrupts disabled.
+Interrupts should be disabled as early as possible in
+the initialization sequence and remain disabled until
+the first context switch.
+
+@page
+@subsection INITIALIZE_BEFORE_DRIVERS - Perform Initialization Before Device Drivers
+
+@cindex initialize RTEMS before device drivers
+
+@subheading CALLING SEQUENCE:
+
+@ifset is-C
+@findex rtems_initialize_before_drivers
+@example
+void rtems_initialize_before_drivers(void);
+@end example
+@end ifset
+
+@ifset is-Ada
+@example
+NOT SUPPORTED FROM Ada BINDING
+@end example
+@end ifset
+
+@subheading DIRECTIVE STATUS CODES:
+
+NONE
+
+@subheading DESCRIPTION:
+
+This directive is called by the Board Support Package as the
+second step in initializing RTEMS.  This directive performs
+initialization that must occur between basis RTEMS data structure
+initialization and device driver initialization.  In particular,
+in a multiprocessor configuration, this directive will create the
+MPCI Server Task.  This directive returns to the caller after
+completing the basic RTEMS initialization.
 
 @subheading NOTES:
 
-The application must use only one of the two
-initialization sequences:
-@code{@value{DIRPREFIX}initialize_executive} or
-@code{@value{DIRPREFIX}initialize_executive_early} and 
-@code{@value{DIRPREFIX}initialize_executive_late}.
+The Initialization Manager directives must be used in the
+proper sequence and invokved only once in the life of an application.
+
+This directive must be invoked with interrupts disabled.
+Interrupts should be disabled as early as possible in
+the initialization sequence and remain disabled until
+the first context switch.
 
 @page
-@subsection INITIALIZE_EXECUTIVE_LATE - Complete Initialization and Start Multitasking
+@subsection INITIALIZE_DEVICE_DRIVERS - Initialize Device Drivers
+
+@cindex initialize device drivers
+
+@subheading CALLING SEQUENCE:
+
+@ifset is-C
+@findex rtems_initialize_device_drivers
+@example
+void rtems_initialize_device_drivers(void);
+@end example
+@end ifset
+
+@ifset is-Ada
+@example
+NOT SUPPORTED FROM Ada BINDING
+@end example
+@end ifset
+
+@subheading DIRECTIVE STATUS CODES:
+
+NONE
+
+@subheading DESCRIPTION:
+
+This directive is called by the Board Support Package as the
+third step in initializing RTEMS.  This directive initializes
+all statically configured device drivers and performs all RTEMS
+initialization which requires device drivers to be initialized.
+
+In a multiprocessor configuration, this service will initialize
+the Multiprocessor Communications Interface (MPCI) and synchronize
+with the other nodes in the system. 
+
+After this directive is executed, control will be returned to
+the Board Support Package framework.
+
+@subheading NOTES:
+
+The Initialization Manager directives must be used in the
+proper sequence and invokved only once in the life of an application.
+
+This directive must be invoked with interrupts disabled.
+Interrupts should be disabled as early as possible in
+the initialization sequence and remain disabled until
+the first context switch.
+
+@page
+@subsection INITIALIZE_START_MULTITASKING - Complete Initialization and Start Multitasking
 
 @cindex initialize RTEMS
 @cindex start multitasking
@@ -229,11 +349,9 @@ initialization sequences:
 @subheading CALLING SEQUENCE:
 
 @ifset is-C
-@findex rtems_initialize_executive_late
+@findex rtems_initialize_start_multitasking
 @example
-void rtems_initialize_executive_late(
-  rtems_interrupt_level bsp_level
-);
+void rtems_initialize_start_multitasking(void);
 @end example
 @end ifset
 
@@ -249,21 +367,15 @@ NONE
 
 @subheading DESCRIPTION:
 
-This directive is called after the
-@code{@value{DIRPREFIX}initialize_executive_early}
-directive has been called to complete
-the RTEMS initialization sequence and initiate multitasking.
-The interrupt level returned by the
-@code{@value{DIRPREFIX}initialize_executive_early}
-directive should be in bsp_level and this value is restored as
-part of this directive returning to the caller after the
-@code{@value{DIRPREFIX}shutdown_executive}
-directive is invoked.
+This directive is called after the other Initialization Manager
+directives have successfully completed.  This directive
+initiates multitasking and performs a context switch to
+the first user application task and enables interrupts as
+a side-effect of that context switch.
 
 @subheading NOTES:
 
-This directive MUST be the second RTEMS directive
-called and it DOES NOT RETURN to the caller until the
+This directive @b{DOES NOT RETURN} to the caller until the
 @code{@value{DIRPREFIX}shutdown_executive} is invoked.
 
 This directive causes all nodes in the system to
@@ -271,14 +383,6 @@ verify that certain configuration parameters are the same as
 those of the local node.  If an inconsistency is detected, then
 a fatal error is generated.
 
-The application must use only one of the two
-initialization sequences:
-@code{@value{DIRPREFIX}initialize_executive} or
-@code{@value{DIRPREFIX}initialize_executive_early} and
-@code{@value{DIRPREFIX}initialize_executive_late}.
-
-
-
 @page
 @subsection SHUTDOWN_EXECUTIVE - Shutdown RTEMS