Subversion Repositories openrisc

;/*

;    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.

;

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;

;    This file is part of the FreeRTOS distribution.

;

;    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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        EXTERN pxCurrentTCB

        EXTERN ulCriticalNesting

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; Context save and restore macro definitions

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

portSAVE_CONTEXT MACRO

        ; Push R0 as we are going to use the register.

        STMDB   SP!, {R0}

        ; Set R0 to point to the task stack pointer.

        STMDB   SP, {SP}^

        NOP

        SUB             SP, SP, #4

        LDMIA   SP!, {R0}

        ; Push the return address onto the stack.

        STMDB   R0!, {LR}

        ; Now we have saved LR we can use it instead of R0.

        MOV             LR, R0

        ; Pop R0 so we can save it onto the system mode stack.

        LDMIA   SP!, {R0}

        ; Push all the system mode registers onto the task stack.

        STMDB   LR, {R0-LR}^

        NOP

        SUB             LR, LR, #60

        ; Push the SPSR onto the task stack.

        MRS             R0, SPSR

        STMDB   LR!, {R0}

        LDR             R0, =ulCriticalNesting

        LDR             R0, [R0]

        STMDB   LR!, {R0}

        ; Store the new top of stack for the task.

        LDR             R1, =pxCurrentTCB

        LDR             R0, [R1]

        STR             LR, [R0]

        ENDM

portRESTORE_CONTEXT MACRO

        ; Set the LR to the task stack.

        LDR             R1, =pxCurrentTCB

        LDR             R0, [R1]

        LDR             LR, [R0]

        ; The critical nesting depth is the first item on the stack.

        ; Load it into the ulCriticalNesting variable.

        LDR             R0, =ulCriticalNesting

        LDMFD   LR!, {R1}

        STR             R1, [R0]

        ; Get the SPSR from the stack.

        LDMFD   LR!, {R0}

        MSR             SPSR_cxsf, R0

        ; Restore all system mode registers for the task.

        LDMFD   LR, {R0-R14}^

        NOP

        ; Restore the return address.

        LDR             LR, [LR, #+60]

        ; And return - correcting the offset in the LR to obtain the

        ; correct address.

        SUBS    PC, LR, #4

        ENDM