2 FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.
\r
4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
\r
5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
7 ***************************************************************************
\r
9 * FreeRTOS tutorial books are available in pdf and paperback. *
\r
10 * Complete, revised, and edited pdf reference manuals are also *
\r
13 * Purchasing FreeRTOS documentation will not only help you, by *
\r
14 * ensuring you get running as quickly as possible and with an *
\r
15 * in-depth knowledge of how to use FreeRTOS, it will also help *
\r
16 * the FreeRTOS project to continue with its mission of providing *
\r
17 * professional grade, cross platform, de facto standard solutions *
\r
18 * for microcontrollers - completely free of charge! *
\r
20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
\r
22 * Thank you for using FreeRTOS, and thank you for your support! *
\r
24 ***************************************************************************
\r
27 This file is part of the FreeRTOS distribution.
\r
29 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
30 the terms of the GNU General Public License (version 2) as published by the
\r
31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
33 >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
\r
34 distribute a combined work that includes FreeRTOS without being obliged to
\r
35 provide the source code for proprietary components outside of the FreeRTOS
\r
38 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
\r
39 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
\r
40 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
\r
41 details. You should have received a copy of the GNU General Public License
\r
42 and the FreeRTOS license exception along with FreeRTOS; if not it can be
\r
43 viewed here: http://www.freertos.org/a00114.html and also obtained by
\r
44 writing to Real Time Engineers Ltd., contact details for whom are available
\r
45 on the FreeRTOS WEB site.
\r
49 ***************************************************************************
\r
51 * Having a problem? Start by reading the FAQ "My application does *
\r
52 * not run, what could be wrong?" *
\r
54 * http://www.FreeRTOS.org/FAQHelp.html *
\r
56 ***************************************************************************
\r
59 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
\r
60 license and Real Time Engineers Ltd. contact details.
\r
62 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
63 including FreeRTOS+Trace - an indispensable productivity tool, and our new
\r
64 fully thread aware and reentrant UDP/IP stack.
\r
66 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
\r
67 Integrity Systems, who sell the code with commercial support,
\r
68 indemnification and middleware, under the OpenRTOS brand.
\r
70 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
\r
71 engineered and independently SIL3 certified version for use in safety and
\r
72 mission critical applications that require provable dependability.
\r
75 .extern vTaskSwitchContext
\r
79 # Exported to start the first task.
\r
80 .globl restore_sp_from_pxCurrentTCB
\r
82 # Entry point for exceptions.
\r
83 .section .exceptions.entry, "xa"
\r
85 # Save the entire context of a task.
\r
87 addi ea, ea, -4 # Point to the next instruction.
\r
88 addi sp, sp, -116 # Create space on the stack.
\r
90 # Leave a gap for muldiv 0
\r
106 rdctl r5, estatus # Save the eStatus
\r
108 stw ea, 72(sp) # Save the PC
\r
109 stw r16, 76(sp) # Save the remaining registers
\r
120 save_sp_to_pxCurrentTCB:
\r
121 movia et, pxCurrentTCB # Load the address of the pxCurrentTCB pointer
\r
122 ldw et, (et) # Load the value of the pxCurrentTCB pointer
\r
123 stw sp, (et) # Store the stack pointer into the top of the TCB
\r
125 .section .exceptions.irqtest, "xa"
\r
128 * Test to see if the exception was a software exception or caused
\r
129 * by an external interrupt, and vector accordingly.
\r
131 rdctl r4, ipending # Load the Pending Interrupts indication
\r
132 rdctl r5, estatus # Load the eStatus (enabled interrupts).
\r
133 andi r2, r5, 1 # Are interrupts enabled globally.
\r
134 beq r2, zero, soft_exceptions # Interrupts are not enabled.
\r
135 beq r4, zero, soft_exceptions # There are no interrupts triggered.
\r
137 .section .exceptions.irqhandler, "xa"
\r
139 call alt_irq_handler # Call the alt_irq_handler to deliver to the registered interrupt handler.
\r
141 .section .exceptions.irqreturn, "xa"
\r
142 restore_sp_from_pxCurrentTCB:
\r
143 movia et, pxCurrentTCB # Load the address of the pxCurrentTCB pointer
\r
144 ldw et, (et) # Load the value of the pxCurrentTCB pointer
\r
145 ldw sp, (et) # Load the stack pointer with the top value of the TCB
\r
148 ldw ra, 0(sp) # Restore the registers.
\r
149 # Leave a gap for muldiv 0.
\r
165 ldw et, 68(sp) # Load the eStatus
\r
166 wrctl estatus, et # Write the eStatus
\r
167 ldw ea, 72(sp) # Load the Program Counter
\r
178 addi sp, sp, 116 # Release stack space
\r
180 eret # Return to address ea, loading eStatus into Status.
\r
182 .section .exceptions.soft, "xa"
\r
184 ldw et, 0(ea) # Load the instruction where the interrupt occured.
\r
185 movhi at, %hi(0x003B683A) # Load the registers with the trap instruction code
\r
186 ori at, at, %lo(0x003B683A)
\r
187 cmpne et, et, at # Compare the trap instruction code to the last excuted instruction
\r
188 beq et, r0, call_scheduler # its a trap so switchcontext
\r
189 break # This is an un-implemented instruction or muldiv problem.
\r
190 br restore_context # its something else
\r
193 addi ea, ea, 4 # A trap was called, increment the program counter so it is not called again.
\r
194 stw ea, 72(sp) # Save the new program counter to the context.
\r
195 call vTaskSwitchContext # Pick the next context.
\r
196 br restore_sp_from_pxCurrentTCB # Switch in the task context and restore.
\r