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Add in the critical nesting save and restore.

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Richard Barry 2006-08-28 10:19:21 +00:00
parent 9269733ed0
commit 7c183b2f1c
1 changed files with 17 additions and 12 deletions
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29
Source/portable/IAR/ATMega323/portmacro.s90
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@ -18,13 +18,13 @@
;
; A special exception to the GPL can be applied should you wish to distribute
; a combined work that includes FreeRTOS.org, without being obliged to provide
; the source code for any proprietary components. See the licensing section
; the source code for any proprietary components. See the licensing section
; of http://www.FreeRTOS.org for full details of how and when the exception
; can be applied.
;
; ***************************************************************************
; See http://www.FreeRTOS.org for documentation, latest information, license
; and contact details. Please ensure to read the configuration and relevant
; See http://www.FreeRTOS.org for documentation, latest information, license
; and contact details. Please ensure to read the configuration and relevant
; port sections of the online documentation.
; ***************************************************************************
@ -45,6 +45,7 @@ EXTERN SIG_UART_DATA
EXTERN vTaskSwitchContext
EXTERN pxCurrentTCB
EXTERN vTaskIncrementTick
EXTERN uxCriticalNesting
; Functions implemented in this file
; ----------------------------------
@ -88,15 +89,15 @@ PUBLIC vPortStart
; ------------------------------------------------------
;
; The IAR compiler does not fully support inline assembler, so saving and
; restoring a task context has to be written in an asm file.
; restoring a task context has to be written in an asm file.
;
; vPortYield() and vPortYieldFromTick() are usually written in C. Doing
; so in this case would required calls to be made to portSAVE_CONTEXT() and
; portRESTORE_CONTEXT(). This is dis-advantageous as the context switch
; function would require two extra jump and return instructions over the
; WinAVR equivalent.
; portRESTORE_CONTEXT(). This is dis-advantageous as the context switch
; function would require two extra jump and return instructions over the
; WinAVR equivalent.
;
; To avoid this I have opted to implement both vPortYield() and
; To avoid this I have opted to implement both vPortYield() and
; vPortYieldFromTick() in this assembly file. For convenience
; portSAVE_CONTEXT and portRESTORE_CONTEXT are implemented as macros.
@ -140,6 +141,8 @@ portSAVE_CONTEXT MACRO
st -y, r27
st -y, r30
st -y, r31
lds r0, uxCriticalNesting
st -y, r0 ; Store the critical nesting counter.
lds r26, pxCurrentTCB ; Finally save the software stack pointer (Y ...
lds r27, pxCurrentTCB + 1 ; ... register) into the TCB.
@ -155,10 +158,12 @@ portRESTORE_CONTEXT MACRO
ld r28, x+ ; the TCB into the software stack pointer (...
ld r29, x+ ; ... the Y register).
ld r0, y+
sts uxCriticalNesting, r0
ld r31, y+ ; Restore the registers down to R0. The Y
ld r30, y+ ; register is missing from this list as it
ld r27, y+ ; has already been restored.
ld r26, y+
ld r26, y+
ld r25, y+
ld r24, y+
ld r23, y+
@ -202,9 +207,9 @@ portRESTORE_CONTEXT MACRO
; vPortYield() and vPortYieldFromTick()
; -------------------------------------
;
; Manual and preemptive context switch functions respectively.
; The IAR compiler does not fully support inline assembler,
; so these are implemented here rather than the more usually
; Manual and preemptive context switch functions respectively.
; The IAR compiler does not fully support inline assembler,
; so these are implemented here rather than the more usually
; place of within port.c.
vPortYield: