;/***************************************************************************
; * Copyright (c) 2024 Microsoft Corporation 
; * 
; * This program and the accompanying materials are made available under the
; * terms of the MIT License which is available at
; * https://opensource.org/licenses/MIT.
; * 
; * SPDX-License-Identifier: MIT
; **************************************************************************/
;
;
;/**************************************************************************/
;/**************************************************************************/
;/**                                                                       */ 
;/** ThreadX Component                                                     */ 
;/**                                                                       */
;/**   Initialize                                                          */
;/**                                                                       */
;/**************************************************************************/
;/**************************************************************************/
;

    .GLB __tx_initialize_unused_memory

    IPR03    .EQU  87303H
    IEN03    .EQU  87203H

    .SECTION P,CODE
    
;
;/**************************************************************************/ 
;/*                                                                        */ 
;/*  FUNCTION                                               RELEASE        */ 
;/*                                                                        */ 
;/*    _tx_initialize_low_level                             RXv3/CCRX      */
;/*                                                           6.1.11       */
;/*  AUTHOR                                                                */ 
;/*                                                                        */ 
;/*    William E. Lamie, Microsoft Corporation                             */
;/*                                                                        */ 
;/*  DESCRIPTION                                                           */ 
;/*                                                                        */ 
;/*    This function is responsible for any low-level processor            */ 
;/*    initialization, including setting up interrupt vectors, setting     */ 
;/*    up a periodic timer interrupt source, saving the system stack       */ 
;/*    pointer for use in ISR processing later, and finding the first      */ 
;/*    available RAM memory address for tx_application_define.             */ 
;/*                                                                        */ 
;/*  INPUT                                                                 */ 
;/*                                                                        */ 
;/*    None                                                                */ 
;/*                                                                        */ 
;/*  OUTPUT                                                                */ 
;/*                                                                        */ 
;/*    None                                                                */ 
;/*                                                                        */ 
;/*  CALLS                                                                 */ 
;/*                                                                        */ 
;/*    None                                                                */ 
;/*                                                                        */ 
;/*  CALLED BY                                                             */ 
;/*                                                                        */ 
;/*    _tx_initialize_kernel_enter           ThreadX entry function        */ 
;/*                                                                        */ 
;/*  RELEASE HISTORY                                                       */ 
;/*                                                                        */ 
;/*    DATE              NAME                      DESCRIPTION             */ 
;/*                                                                        */ 
;/*  06-02-2021     William E. Lamie         Initial Version 6.1.7         */
;/*  10-15-2021     William E. Lamie         Modified comment(s),          */ 
;/*                                            resulting in version 6.1.9  */ 
;/*  01-31-2022     William E. Lamie         Modified comment(s),          */
;/*                                            resulting in version 6.1.10 */
;/*  04-25-2022     William E. Lamie         Modified comment(s),          */
;/*                                            resulting in version 6.1.11 */
;/*                                                                        */ 
;/**************************************************************************/ 

    .GLB __tx_initialize_low_level
__tx_initialize_low_level:
;
;    /* Save the first available memory address.  */
;    _tx_initialize_unused_memory =  (VOID_PTR) &free_mem_start;
;
    MOV.L    #free_mem_start, R1                ; Pickup unused memory address
    MOV.L    #__tx_initialize_unused_memory,R2
    MOV.L    R1,[R2]                            ; Save first free memory address

;   /* Set priority of SWINT to 1. */
    MOV.L    #IPR03, r1
    MOV.L    #1, r2
    MOV.B    r2, [r1]

;   /* Enable SWINT. */
    MOV.L    #IEN03,r1
    MOV.B    [r1], r2
    OR       #(1 << 3), r2
    MOV.B    r2, [r1]

    RTS                                    

    .SECTION    FREEMEM ,DATA, ALIGN=4
free_mem_start:
    .BLKL 8              ; this section is last in the link map so we can access the end of RAM memory

    .END