mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
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188 lines
7.3 KiB
ArmAsm
188 lines
7.3 KiB
ArmAsm
/*
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FreeRTOS V8.0.0:rc1 - Copyright (C) 2014 Real Time Engineers Ltd.
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All rights reserved
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VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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***************************************************************************
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* *
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* FreeRTOS provides completely free yet professionally developed, *
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* robust, strictly quality controlled, supported, and cross *
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* platform software that has become a de facto standard. *
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* *
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* Help yourself get started quickly and support the FreeRTOS *
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* project by purchasing a FreeRTOS tutorial book, reference *
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* manual, or both from: http://www.FreeRTOS.org/Documentation *
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* *
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* Thank you! *
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* *
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***************************************************************************
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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
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the terms of the GNU General Public License (version 2) as published by the
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Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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>>! NOTE: The modification to the GPL is included to allow you to distribute
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>>! a combined work that includes FreeRTOS without being obliged to provide
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>>! the source code for proprietary components outside of the FreeRTOS
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>>! kernel.
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FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. Full license text is available from the following
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link: http://www.freertos.org/a00114.html
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1 tab == 4 spaces!
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***************************************************************************
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* *
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* Having a problem? Start by reading the FAQ "My application does *
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* not run, what could be wrong?" *
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* *
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* http://www.FreeRTOS.org/FAQHelp.html *
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* *
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***************************************************************************
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http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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license and Real Time Engineers Ltd. contact details.
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http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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compatible FAT file system, and our tiny thread aware UDP/IP stack.
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http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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licenses offer ticketed support, indemnification and middleware.
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http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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engineered and independently SIL3 certified version for use in safety and
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mission critical applications that require provable dependability.
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1 tab == 4 spaces!
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*/
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.extern vTaskSwitchContext
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.set noat
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# Exported to start the first task.
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.globl restore_sp_from_pxCurrentTCB
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# Entry point for exceptions.
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.section .exceptions.entry, "xa"
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# Save the entire context of a task.
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save_context:
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addi ea, ea, -4 # Point to the next instruction.
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addi sp, sp, -116 # Create space on the stack.
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stw ra, 0(sp)
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# Leave a gap for muldiv 0
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stw at, 8(sp)
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stw r2, 12(sp)
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stw r3, 16(sp)
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stw r4, 20(sp)
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stw r5, 24(sp)
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stw r6, 28(sp)
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stw r7, 32(sp)
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stw r8, 36(sp)
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stw r9, 40(sp)
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stw r10, 44(sp)
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stw r11, 48(sp)
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stw r12, 52(sp)
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stw r13, 56(sp)
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stw r14, 60(sp)
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stw r15, 64(sp)
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rdctl r5, estatus # Save the eStatus
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stw r5, 68(sp)
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stw ea, 72(sp) # Save the PC
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stw r16, 76(sp) # Save the remaining registers
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stw r17, 80(sp)
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stw r18, 84(sp)
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stw r19, 88(sp)
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stw r20, 92(sp)
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stw r21, 96(sp)
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stw r22, 100(sp)
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stw r23, 104(sp)
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stw gp, 108(sp)
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stw fp, 112(sp)
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save_sp_to_pxCurrentTCB:
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movia et, pxCurrentTCB # Load the address of the pxCurrentTCB pointer
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ldw et, (et) # Load the value of the pxCurrentTCB pointer
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stw sp, (et) # Store the stack pointer into the top of the TCB
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.section .exceptions.irqtest, "xa"
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hw_irq_test:
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/*
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* Test to see if the exception was a software exception or caused
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* by an external interrupt, and vector accordingly.
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*/
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rdctl r4, ipending # Load the Pending Interrupts indication
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rdctl r5, estatus # Load the eStatus (enabled interrupts).
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andi r2, r5, 1 # Are interrupts enabled globally.
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beq r2, zero, soft_exceptions # Interrupts are not enabled.
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beq r4, zero, soft_exceptions # There are no interrupts triggered.
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.section .exceptions.irqhandler, "xa"
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hw_irq_handler:
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call alt_irq_handler # Call the alt_irq_handler to deliver to the registered interrupt handler.
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.section .exceptions.irqreturn, "xa"
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restore_sp_from_pxCurrentTCB:
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movia et, pxCurrentTCB # Load the address of the pxCurrentTCB pointer
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ldw et, (et) # Load the value of the pxCurrentTCB pointer
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ldw sp, (et) # Load the stack pointer with the top value of the TCB
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restore_context:
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ldw ra, 0(sp) # Restore the registers.
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# Leave a gap for muldiv 0.
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ldw at, 8(sp)
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ldw r2, 12(sp)
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ldw r3, 16(sp)
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ldw r4, 20(sp)
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ldw r5, 24(sp)
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ldw r6, 28(sp)
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ldw r7, 32(sp)
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ldw r8, 36(sp)
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ldw r9, 40(sp)
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ldw r10, 44(sp)
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ldw r11, 48(sp)
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ldw r12, 52(sp)
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ldw r13, 56(sp)
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ldw r14, 60(sp)
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ldw r15, 64(sp)
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ldw et, 68(sp) # Load the eStatus
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wrctl estatus, et # Write the eStatus
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ldw ea, 72(sp) # Load the Program Counter
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ldw r16, 76(sp)
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ldw r17, 80(sp)
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ldw r18, 84(sp)
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ldw r19, 88(sp)
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ldw r20, 92(sp)
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ldw r21, 96(sp)
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ldw r22, 100(sp)
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ldw r23, 104(sp)
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ldw gp, 108(sp)
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ldw fp, 112(sp)
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addi sp, sp, 116 # Release stack space
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eret # Return to address ea, loading eStatus into Status.
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.section .exceptions.soft, "xa"
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soft_exceptions:
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ldw et, 0(ea) # Load the instruction where the interrupt occured.
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movhi at, %hi(0x003B683A) # Load the registers with the trap instruction code
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ori at, at, %lo(0x003B683A)
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cmpne et, et, at # Compare the trap instruction code to the last excuted instruction
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beq et, r0, call_scheduler # its a trap so switchcontext
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break # This is an un-implemented instruction or muldiv problem.
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br restore_context # its something else
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call_scheduler:
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addi ea, ea, 4 # A trap was called, increment the program counter so it is not called again.
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stw ea, 72(sp) # Save the new program counter to the context.
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call vTaskSwitchContext # Pick the next context.
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br restore_sp_from_pxCurrentTCB # Switch in the task context and restore.
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