Subversion Repositories openrisc_2011-10-31

;/*
;    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
;
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;
;    This file is part of the FreeRTOS distribution.
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;    FreeRTOS is free software; you can redistribute it and/or modify it under
;    the terms of the GNU General Public License (version 2) as published by the
;    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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;    a combined work that includes FreeRTOS without being obliged to provide the
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;*/

        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