--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/nucleus/tcd.c	Fri Oct 16 06:23:26 2020 +0000
@@ -0,0 +1,300 @@
+/*************************************************************************/
+/*                                                                       */
+/*               Copyright Mentor Graphics Corporation 2002              */
+/*                         All Rights Reserved.                          */
+/*                                                                       */
+/* THIS WORK CONTAINS TRADE SECRET AND PROPRIETARY INFORMATION WHICH IS  */
+/* THE PROPERTY OF MENTOR GRAPHICS CORPORATION OR ITS LICENSORS AND IS   */
+/* SUBJECT TO LICENSE TERMS.                                             */
+/*                                                                       */
+/*************************************************************************/
+
+/*************************************************************************/
+/*                                                                       */
+/* FILE NAME                                               VERSION       */
+/*                                                                       */
+/*      tcd.c                                          Nucleus PLUS 1.14 */
+/*                                                                       */
+/* COMPONENT                                                             */
+/*                                                                       */
+/*      TC - Thread Control                                              */
+/*                                                                       */
+/* DESCRIPTION                                                           */
+/*                                                                       */
+/*      This file contains global data structures for use within this    */
+/*      component.                                                       */
+/*                                                                       */
+/* DATA STRUCTURES                                                       */
+/*                                                                       */
+/*      TCD_Created_Tasks_List              Pointer to the linked-list   */
+/*                                            of created tasks           */
+/*      TCD_Total_Tasks                     Total number of created tasks*/
+/*      TCD_Priority_List                   Array of pointers to ready   */
+/*                                            tasks, indexed by priority */
+/*      TCD_Execute_Task                    Highest priority task to     */
+/*                                            execute                    */
+/*      TCD_Priority_Groups                 Bit map of 32 groups of task */
+/*                                            priority                   */
+/*      TCD_Sub_Priority_Groups             An array of 32 sub-priority  */
+/*                                            groups                     */
+/*      TCD_Lowest_Set_Bit                  Lookup table to find the     */
+/*                                            lowest bit set in a byte   */
+/*      TCD_Highest_Priority                Highest priority ready       */
+/*      TCD_Created_HISRs_List              Pointer to the linked-list   */
+/*                                            of created HISRs           */
+/*      TCD_Total_HISRs                     Total number of created HISRs*/
+/*      TCD_Active_HISR_Heads               Active HISR list head ptrs   */
+/*      TCD_Active_HISR_Tails               Active HISR list tail ptrs   */
+/*      TCD_Execute_HISR                    Highest priority HISR to     */
+/*                                            execute                    */
+/*      TCD_Current_Thread                  Pointer to the currently     */
+/*                                            executing thread           */
+/*      TCD_Registered_LISRs                List of registered LISRs     */
+/*      TCD_LISR_Pointers                   Actual LISR pointers         */
+/*      TCD_Interrupt_Count                 Count of ISRs in progress    */
+/*      TCD_Stack_Switched                  Flag indicating that stack   */
+/*                                            was switched in an ISR     */
+/*      TCD_List_Protect                    Task list protection         */
+/*      TCD_System_Protect                  System protection            */
+/*      TCD_System_Stack                    System stack pointer - top   */
+/*      TCD_LISR_Protect                    Protect LISR registration    */
+/*      TCD_HISR_Protect                    Protect the list of created  */
+/*                                            HISRs                      */
+/*      TCD_Interrupt_Level                 Enable interrupt level       */
+/*      TCD_Unhandled_Interrupt             Contains the most recent     */
+/*                                            unhandled interrupt in     */
+/*                                            system error conditions    */
+/*                                                                       */
+/* FUNCTIONS                                                             */
+/*                                                                       */
+/*      None                                                             */
+/*                                                                       */
+/* DEPENDENCIES                                                          */
+/*                                                                       */
+/*      cs_defs.h                           Common Service constants     */
+/*      tc_defs.h                           Thread Control constants     */
+/*                                                                       */
+/* HISTORY                                                               */
+/*                                                                       */
+/*         DATE                    REMARKS                               */
+/*                                                                       */
+/*      03-01-1993      Created initial version 1.0                      */
+/*      04-19-1993      Verified version 1.0                             */
+/*      01-01-1993      Added variable to save last                      */
+/*                        unhandled interrupt in system                  */
+/*                        error conditions, resulting in                 */
+/*                        version 1.0a                                   */
+/*      11-01-1993      Verified version 1.0a                            */
+/*      03-01-1994      Change schedule protection to a                  */
+/*                        system protection to improve                   */
+/*                        performance, resulting in                      */
+/*                        version 1.1                                    */
+/*                                                                       */
+/*      03-18-1994      Verified version 1.1                             */
+/*      04-17-1996      updated to version 1.2                           */
+/*      03-24-1998      Released version 1.3.                            */
+/*      03-26-1999      Released 1.11m (new release                      */
+/*                        numbering scheme)                              */
+/*      04-23-2001      Made TCD_LISR_Pointers array an exclusive count  */
+/*      04-17-2002      Released version 1.13m                           */
+/*      11-07-2002      Released version 1.14                            */
+/*************************************************************************/
+#define         NU_SOURCE_FILE
+
+#include        "cs_defs.h"                 /* Common Service constants  */
+#include        "tc_defs.h"                 /* Thread Control constants  */
+
+
+/* TCD_Created_Tasks_List is the head pointer of the linked list of
+   created tasks.  If the list is NU_NULL, there are no tasks created.  */
+
+CS_NODE        *TCD_Created_Tasks_List;
+
+
+/* TCD_Total_Tasks contains the number of currently created tasks.  */
+
+UNSIGNED        TCD_Total_Tasks;
+
+
+/* TCD_Priority_List is an array of TCB pointers.  Each element of the array
+   is effectively the head pointer of the list of tasks ready for execution
+   at that priority.  If the pointer is NULL, there are no tasks ready
+   for execution at that priority.  The array is indexed by priority.  */
+
+TC_TCB         *TCD_Priority_List[TC_PRIORITIES];
+
+
+/* TCD_Priority_Groups is a 32-bit unsigned integer that is used as a bit
+   map.  Each bit corresponds to an 8-priority group.  For example, if bit 0
+   is set, at least one task of priority 0 through 8 is ready for execution. */
+
+UNSIGNED        TCD_Priority_Groups;
+
+
+/* TCD_Sub_Priority_Groups is an array of sub-priority groups.  These are
+   also used as bit maps.  Index 0 of this array corresponds to priorities
+   0 through 8.  Bit 0 of this element represents priority 0, while bit 7
+   represents priority 7.  */
+
+DATA_ELEMENT    TCD_Sub_Priority_Groups[TC_MAX_GROUPS];
+
+
+/* TCD_Lowest_Set_Bit is nothing more than a standard lookup table.  The
+   table is indexed by values ranging from 1 to 255.  The value at that
+   position in the table indicates the number of the lowest set bit.  This is
+   used to determine the highest priority task represented in the previously
+   defined bit maps.  */
+
+UNSIGNED_CHAR  TCD_Lowest_Set_Bit[] = {0,
+   0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0,
+   1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1,
+   0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0,
+   2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2,
+   0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0,
+   1, 0, 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1,
+   0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
+   4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3,
+   0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0,
+   1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1,
+   0, 2, 0, 1, 0};
+
+
+/* TCD_Highest_Priority contains the highest priority task ready for execution.
+   Note that this does not necessarily represent the priority of the currently
+   executing task.  This is true if the currently executing task has preemption
+   disabled.  If no tasks are executing, this variable is set to the maximum
+   priority.  */
+
+INT             TCD_Highest_Priority;
+
+
+/* TCD_Execute_Task is a pointer to the task to execute.  Note that this
+   pointer does not necessarily point to the currently executing task.  There
+   are several points in the system where this is true.  One situation is
+   when preemption is about to take place.  Another situation can result from
+   a internal protection conflict.  */
+
+TC_TCB         *TCD_Execute_Task;
+
+
+/* TCD_Created_HISRs_List is the head pointer of the list of created High-
+   Level Interrupt Service Routines (HISR).  If this pointer is NU_NULL, there
+   are no HISRs currently created.  */
+
+CS_NODE        *TCD_Created_HISRs_List;
+
+
+/* TCD_Total_HISRs contains the number of currently created HISRs.  */
+
+UNSIGNED        TCD_Total_HISRs;
+
+
+/* TCD_Active_HISR_Heads is an array of active HISR list head pointers.
+   There are three HISR priorities available.  The HISR priority is an index
+   into this table.  Priority/index 0 represents the highest priority.  */
+
+TC_HCB         *TCD_Active_HISR_Heads[TC_HISR_PRIORITIES];
+
+
+/* TCD_Active_HISR_Tails is an array of active HISR list tail pointers.
+   There are three HISR priorities available.  The HISR priority is an index
+   into this table.  Priority/index 0 represents the highest priority.  */
+
+TC_HCB          *TCD_Active_HISR_Tails[TC_HISR_PRIORITIES];
+
+
+/* TCD_Execute_HISR contains a pointer to the highest priority HISR to execute.
+   If this pointer is NU_NULL, no HISRs are currently activated.  Note that
+   the current thread pointer is not always equal to this pointer.  */
+
+TC_HCB         *TCD_Execute_HISR;
+
+
+/* TCD_Current_Thread points to the control block of the currently executing
+   thread of execution.  Therefore, this variable points at either a TC_TCB
+   or a TC_HCB structure.  Except for initialization, this variable is set
+   and cleared in the target dependent portion of this component.  */
+
+VOID           *TCD_Current_Thread;
+
+
+/* TCD_System_Stack contains the system stack base pointer.  When the system
+   is idle or in interrupt processing the system stack pointer is used.  This
+   variable is usually setup during target dependent initialization.  */
+
+VOID           *TCD_System_Stack;
+
+
+/* TCD_Registered_LISRs is a list that specifies whether or not a
+   LISR is registered for a given interrupt vector.  If the value in the
+   list indexed by the vector is non-zero, then that value can be used
+   as the index into the list of LISR pointers to find the actual registered
+   LISR.  */
+
+UNSIGNED_CHAR   TCD_Registered_LISRs[NU_MAX_VECTORS+1];
+
+
+/* TCD_LISR_Pointers is a list of LISR pointers that indicate the LISR function
+   to call when the interrupt occurs.  If the entry is NULL, it is
+   available.  */
+
+VOID    (*TCD_LISR_Pointers[NU_MAX_LISRS+1])(INT vector);
+
+
+/* TCD_Interrupt_Count contains the number of Interrupt Service Routines (ISRs)
+   currently in progress.  If the contents of this variable is zero, then no
+   interrupts are in progress.  If the contents are greater than 1, nested
+   interrupts are being processed.  */
+
+INT     TCD_Interrupt_Count;
+
+
+/* TCD_Stack_Switched contains a flag indicating that the system stack was
+   switched to after the thread's context was saved.  This variable is not
+   used in all ports.  */
+
+INT     TCD_Stack_Switched;
+
+
+/* TCD_List_Protect is a structure that is used to protect against multiple
+   access to the list of established tasks.  */
+
+TC_PROTECT      TCD_List_Protect;
+
+
+/* TCD_System_Protect is a structure that is used to provide protection
+   against multiple threads accessing the same system structures at the
+   same time.  */
+
+TC_PROTECT      TCD_System_Protect;
+
+
+/* TCD_LISR_Protect is a structure that is used to provide protection against
+   multiple threads accessing the LISR registration structures at the same
+   time.  */
+
+TC_PROTECT      TCD_LISR_Protect;
+
+
+/* TCD_HISR_Protect is a structure that is used to provide protection against
+   multiple threads accessing the created HISR linked-list at the same time. */
+
+TC_PROTECT      TCD_HISR_Protect;
+
+
+/* TCD_Interrupt_Level is a variable that contains the enabled interrupt
+   level.  If the target processor does not have multiple enable interrupt
+   levels, this variable is a boolean.  */
+
+INT             TCD_Interrupt_Level;
+
+
+/* TCD_Unhandled_Interrupt is a variable that contains the last unhandled
+   interrupt in system error conditions.  */
+
+INT             TCD_Unhandled_Interrupt;
+
+
+
+
+