Add in the critical nesting save and restore.
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@ -18,13 +18,13 @@
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;
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; A special exception to the GPL can be applied should you wish to distribute
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; a combined work that includes FreeRTOS.org, without being obliged to provide
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; the source code for any proprietary components. See the licensing section
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; the source code for any proprietary components. See the licensing section
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; of http://www.FreeRTOS.org for full details of how and when the exception
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; can be applied.
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;
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; ***************************************************************************
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; See http://www.FreeRTOS.org for documentation, latest information, license
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; and contact details. Please ensure to read the configuration and relevant
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; See http://www.FreeRTOS.org for documentation, latest information, license
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; and contact details. Please ensure to read the configuration and relevant
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; port sections of the online documentation.
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; ***************************************************************************
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@ -45,6 +45,7 @@ EXTERN SIG_UART_DATA
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EXTERN vTaskSwitchContext
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EXTERN pxCurrentTCB
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EXTERN vTaskIncrementTick
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EXTERN uxCriticalNesting
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; Functions implemented in this file
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; ----------------------------------
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@ -88,15 +89,15 @@ PUBLIC vPortStart
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; ------------------------------------------------------
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;
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; The IAR compiler does not fully support inline assembler, so saving and
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; restoring a task context has to be written in an asm file.
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; restoring a task context has to be written in an asm file.
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;
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; vPortYield() and vPortYieldFromTick() are usually written in C. Doing
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; so in this case would required calls to be made to portSAVE_CONTEXT() and
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; portRESTORE_CONTEXT(). This is dis-advantageous as the context switch
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; function would require two extra jump and return instructions over the
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; WinAVR equivalent.
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; portRESTORE_CONTEXT(). This is dis-advantageous as the context switch
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; function would require two extra jump and return instructions over the
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; WinAVR equivalent.
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;
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; To avoid this I have opted to implement both vPortYield() and
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; To avoid this I have opted to implement both vPortYield() and
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; vPortYieldFromTick() in this assembly file. For convenience
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; portSAVE_CONTEXT and portRESTORE_CONTEXT are implemented as macros.
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@ -140,6 +141,8 @@ portSAVE_CONTEXT MACRO
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st -y, r27
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st -y, r30
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st -y, r31
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lds r0, uxCriticalNesting
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st -y, r0 ; Store the critical nesting counter.
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lds r26, pxCurrentTCB ; Finally save the software stack pointer (Y ...
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lds r27, pxCurrentTCB + 1 ; ... register) into the TCB.
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@ -155,10 +158,12 @@ portRESTORE_CONTEXT MACRO
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ld r28, x+ ; the TCB into the software stack pointer (...
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ld r29, x+ ; ... the Y register).
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ld r0, y+
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sts uxCriticalNesting, r0
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ld r31, y+ ; Restore the registers down to R0. The Y
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ld r30, y+ ; register is missing from this list as it
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ld r27, y+ ; has already been restored.
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ld r26, y+
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ld r26, y+
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ld r25, y+
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ld r24, y+
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ld r23, y+
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@ -202,9 +207,9 @@ portRESTORE_CONTEXT MACRO
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; vPortYield() and vPortYieldFromTick()
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; -------------------------------------
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;
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; Manual and preemptive context switch functions respectively.
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; The IAR compiler does not fully support inline assembler,
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; so these are implemented here rather than the more usually
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; Manual and preemptive context switch functions respectively.
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; The IAR compiler does not fully support inline assembler,
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; so these are implemented here rather than the more usually
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; place of within port.c.
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vPortYield:
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