2 FreeRTOS V9.0.1 - Copyright (C) 2017 Real Time Engineers Ltd.
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5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 This file is part of the FreeRTOS distribution.
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9 FreeRTOS is free software; you can redistribute it and/or modify it under
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10 the terms of the GNU General Public License (version 2) as published by the
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11 Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.
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13 ***************************************************************************
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14 >>! NOTE: The modification to the GPL is included to allow you to !<<
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15 >>! distribute a combined work that includes FreeRTOS without being !<<
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16 >>! obliged to provide the source code for proprietary components !<<
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17 >>! outside of the FreeRTOS kernel. !<<
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18 ***************************************************************************
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20 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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21 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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22 FOR A PARTICULAR PURPOSE. Full license text is available on the following
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23 link: http://www.freertos.org/a00114.html
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25 ***************************************************************************
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27 * FreeRTOS provides completely free yet professionally developed, *
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28 * robust, strictly quality controlled, supported, and cross *
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29 * platform software that is more than just the market leader, it *
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30 * is the industry's de facto standard. *
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32 * Help yourself get started quickly while simultaneously helping *
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33 * to support the FreeRTOS project by purchasing a FreeRTOS *
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34 * tutorial book, reference manual, or both: *
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35 * http://www.FreeRTOS.org/Documentation *
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37 ***************************************************************************
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39 http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading
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40 the FAQ page "My application does not run, what could be wrong?". Have you
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41 defined configASSERT()?
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43 http://www.FreeRTOS.org/support - In return for receiving this top quality
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44 embedded software for free we request you assist our global community by
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45 participating in the support forum.
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47 http://www.FreeRTOS.org/training - Investing in training allows your team to
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48 be as productive as possible as early as possible. Now you can receive
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49 FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
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50 Ltd, and the world's leading authority on the world's leading RTOS.
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52 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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53 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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54 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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56 http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
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57 Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
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59 http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
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60 Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
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61 licenses offer ticketed support, indemnification and commercial middleware.
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63 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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64 engineered and independently SIL3 certified version for use in safety and
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65 mission critical applications that require provable dependability.
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70 .extern vTaskSwitchContext
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74 # Exported to start the first task.
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75 .globl restore_sp_from_pxCurrentTCB
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77 # Entry point for exceptions.
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78 .section .exceptions.entry, "xa"
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80 # Save the entire context of a task.
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82 addi ea, ea, -4 # Point to the next instruction.
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83 addi sp, sp, -116 # Create space on the stack.
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85 # Leave a gap for muldiv 0
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101 rdctl r5, estatus # Save the eStatus
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103 stw ea, 72(sp) # Save the PC
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104 stw r16, 76(sp) # Save the remaining registers
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115 save_sp_to_pxCurrentTCB:
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116 movia et, pxCurrentTCB # Load the address of the pxCurrentTCB pointer
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117 ldw et, (et) # Load the value of the pxCurrentTCB pointer
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118 stw sp, (et) # Store the stack pointer into the top of the TCB
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120 .section .exceptions.irqtest, "xa"
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123 * Test to see if the exception was a software exception or caused
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124 * by an external interrupt, and vector accordingly.
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126 rdctl r4, ipending # Load the Pending Interrupts indication
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127 rdctl r5, estatus # Load the eStatus (enabled interrupts).
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128 andi r2, r5, 1 # Are interrupts enabled globally.
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129 beq r2, zero, soft_exceptions # Interrupts are not enabled.
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130 beq r4, zero, soft_exceptions # There are no interrupts triggered.
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132 .section .exceptions.irqhandler, "xa"
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134 call alt_irq_handler # Call the alt_irq_handler to deliver to the registered interrupt handler.
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136 .section .exceptions.irqreturn, "xa"
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137 restore_sp_from_pxCurrentTCB:
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138 movia et, pxCurrentTCB # Load the address of the pxCurrentTCB pointer
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139 ldw et, (et) # Load the value of the pxCurrentTCB pointer
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140 ldw sp, (et) # Load the stack pointer with the top value of the TCB
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143 ldw ra, 0(sp) # Restore the registers.
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144 # Leave a gap for muldiv 0.
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160 ldw et, 68(sp) # Load the eStatus
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161 wrctl estatus, et # Write the eStatus
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162 ldw ea, 72(sp) # Load the Program Counter
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173 addi sp, sp, 116 # Release stack space
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175 eret # Return to address ea, loading eStatus into Status.
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177 .section .exceptions.soft, "xa"
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179 ldw et, 0(ea) # Load the instruction where the interrupt occured.
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180 movhi at, %hi(0x003B683A) # Load the registers with the trap instruction code
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181 ori at, at, %lo(0x003B683A)
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182 cmpne et, et, at # Compare the trap instruction code to the last excuted instruction
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183 beq et, r0, call_scheduler # its a trap so switchcontext
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184 break # This is an un-implemented instruction or muldiv problem.
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185 br restore_context # its something else
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188 addi ea, ea, 4 # A trap was called, increment the program counter so it is not called again.
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189 stw ea, 72(sp) # Save the new program counter to the context.
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190 call vTaskSwitchContext # Pick the next context.
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191 br restore_sp_from_pxCurrentTCB # Switch in the task context and restore.
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