56 lines
1.8 KiB
Plaintext
Executable File
56 lines
1.8 KiB
Plaintext
Executable File
; --------------------------------------------------------------------------------
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; @Title: Readme for FreeRTOS on ARM
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; @Description:
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; This file includes necessary patches for FreeRTOS to support Task aware
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; tracing.
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;
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; @Keywords: awareness, RTOS, FreeRTOS
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; @Author: AME
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; @Copyright: (C) 1989-2019 Lauterbach GmbH, licensed for use with TRACE32(R) only
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; --------------------------------------------------------------------------------
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; $Id: readme.txt 14136 2019-03-15 14:47:46Z amerkle $
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= Task aware Trace =
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== CortexA/R without DataTrace ==
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Applicable for Cortex-A5/A8/A9/A15/A17/A32.
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Applicable for Cortex-A7/R4/R5/R7/R8/R52 (without DataTrace)
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Description: A function T32_Magic_Update is used to write the pxCurrectTCB value to the CONTEXTIDR (C15:0x10d).
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<portasm.s>
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+ .type T32_Magic_Update, %function
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+ T32_Magic_Update:
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+ /* Write the Magic to the ContextID Register */
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+ LDR R0, pxCurrentTCBConst
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+ LDR R0, [R0]
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+ MCR P15, 0x0,R0,C13,C0,0x1
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+ BX R14
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...
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.type FreeRTOS_SWI_Handler, %function
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FreeRTOS_SWI_Handler:
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/* Save the context of the current task and select a new task to run. */
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portSAVE_CONTEXT
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LDR R0, vTaskSwitchContextConst
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BLX R0
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+ BL T32_Magic_Update
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portRESTORE_CONTEXT
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...
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switch_before_exit:
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...
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/* Call the function that selects the new task to execute.
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vTaskSwitchContext() if vTaskSwitchContext() uses LDRD or STRD
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instructions, or 8 byte aligned stack allocated data. LR does not need
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saving as a new LR will be loaded by portRESTORE_CONTEXT anyway. */
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LDR R0, vTaskSwitchContextConst
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BLX R0
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+ BL T32_Magic_Update
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/* Restore the context of, and branch to, the task selected to execute
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next. */
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portRESTORE_CONTEXT
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...
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</portasm.s>
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Setting within TRACE32:
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ETM.ContextID 32
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ETM.TraceON
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ETM.ON
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