;/*
; * FreeRTOS Kernel <DEVELOPMENT BRANCH>
; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
; *
; * SPDX-License-Identifier: MIT
; *
; * Permission is hereby granted, free of charge, to any person obtaining a copy of
; * this software and associated documentation files (the "Software"), to deal in
; * the Software without restriction, including without limitation the rights to
; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
; * the Software, and to permit persons to whom the Software is furnished to do so,
; * subject to the following conditions:
; *
; * The above copyright notice and this permission notice shall be included in all
; * copies or substantial portions of the Software.
; *
; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
; *
; * https://www.FreeRTOS.org
; * https://github.com/FreeRTOS
; *
; */

    IMPORT  ulCriticalNesting       ;
    IMPORT  pxCurrentTCB            ;


    MACRO
    portRESTORE_CONTEXT


    LDR     R0, =pxCurrentTCB       ; Set the LR to the task stack.  The location was...
    LDR     R0, [R0]                ; ... stored in pxCurrentTCB
    LDR     LR, [R0]

    LDR     R0, =ulCriticalNesting  ; The critical nesting depth is the first item on...
    LDMFD   LR!, {R1}               ; ...the stack.  Load it into the ulCriticalNesting var.
    STR     R1, [R0]                ;

    LDMFD   LR!, {R0}               ; Get the SPSR from the stack.
    MSR     SPSR_cxsf, R0           ;

    LDMFD   LR, {R0-R14}^           ; Restore all system mode registers for the task.
    NOP                             ;

    LDR     LR, [LR, #+60]          ; Restore the return address

                                    ; And return - correcting the offset in the LR to obtain ...
    SUBS    PC, LR, #4              ; ...the correct address.

    MEND

; /**********************************************************************/

    MACRO
    portSAVE_CONTEXT


    STMDB   SP!, {R0}               ; Store R0 first as we need to use it.

    STMDB   SP,{SP}^                ; Set R0 to point to the task stack pointer.
    NOP                             ;
    SUB     SP, SP, #4              ;
    LDMIA   SP!,{R0}                ;

    STMDB   R0!, {LR}               ; Push the return address onto the stack.
    MOV     LR, R0                  ; Now we have saved LR we can use it instead of R0.
    LDMIA   SP!, {R0}               ; Pop R0 so we can save it onto the system mode stack.

    STMDB   LR,{R0-LR}^             ; Push all the system mode registers onto the task stack.
    NOP                             ;
    SUB     LR, LR, #60             ;

    MRS     R0, SPSR                ; Push the SPSR onto the task stack.
    STMDB   LR!, {R0}               ;

    LDR     R0, =ulCriticalNesting  ;
    LDR     R0, [R0]                ;
    STMDB   LR!, {R0}               ;

    LDR     R0, =pxCurrentTCB       ; Store the new top of stack for the task.
    LDR     R1, [R0]                ;
    STR     LR, [R1]                ;

    MEND

    END
