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FreeRTOS-Kernel/Source/portable/MPLAB/PIC32MX/ISR_Support.h

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2007-12-02 04:29:54 +08:00
/*
2008-02-22 03:45:27 +08:00
FreeRTOS.org V4.7.2 - Copyright (C) 2003-2008 Richard Barry.
2007-12-02 04:29:54 +08:00
This file is part of the FreeRTOS.org distribution.
FreeRTOS.org is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FreeRTOS.org is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FreeRTOS.org; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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
of http://www.FreeRTOS.org for full details of how and when the exception
can be applied.
***************************************************************************
2008-02-04 03:45:58 +08:00
Please ensure to read the configuration and relevant port sections of the
online documentation.
+++ http://www.FreeRTOS.org +++
Documentation, latest information, license and contact details.
+++ http://www.SafeRTOS.com +++
A version that is certified for use in safety critical systems.
+++ http://www.OpenRTOS.com +++
Commercial support, development, porting, licensing and training services.
2007-12-02 04:29:54 +08:00
***************************************************************************
*/
#include "FreeRTOSConfig.h"
#define portCONTEXT_SIZE 136
#define portEXL_AND_IE_BITS 0x03
#define portEPC_STACK_LOCATION 124
#define portSTATUS_STACK_LOCATION 128
#define portCAUSE_STACK_LOCATION 132
/******************************************************************/
.macro portSAVE_CONTEXT
/* Make room for the context. */
addiu sp, sp, -portCONTEXT_SIZE
/* Get interrupts above the kernel priority enabled again ASAP. First
save the current status so we can manipulate it, and the cause and EPC
registers so we capture their original values in case of interrupt nesting. */
mfc0 k0, _CP0_CAUSE
sw k0, portCAUSE_STACK_LOCATION(sp)
mfc0 k1, _CP0_STATUS
sw k1, portSTATUS_STACK_LOCATION(sp)
/* Also save s6 so we can use it during this interrupt. Any
nesting interrupts should maintain the values of this register
accross the ISR. */
sw s6, 44(sp)
/* s6 holds the EPC value, we may want this during the context switch. */
mfc0 s6, _CP0_EPC
/* Enable interrupts above the kernel priority. */
addiu k0, zero, configKERNEL_INTERRUPT_PRIORITY
ins k1, k0, 10, 6
ins k1, zero, 1, 4
mtc0 k1, _CP0_STATUS
/* Save the context into the space just created. s6 is saved again
here as it now contains the EPC value. */
sw ra, 120(sp)
sw s8, 116(sp)
sw t9, 112(sp)
sw t8, 108(sp)
sw t7, 104(sp)
sw t6, 100(sp)
sw t5, 96(sp)
sw t4, 92(sp)
sw t3, 88(sp)
sw t2, 84(sp)
sw t1, 80(sp)
sw t0, 76(sp)
sw a3, 72(sp)
sw a2, 68(sp)
sw a1, 64(sp)
sw a0, 60(sp)
sw v1, 56(sp)
sw v0, 52(sp)
sw s7, 48(sp)
sw s6, portEPC_STACK_LOCATION(sp)
sw s5, 40(sp)
sw s4, 36(sp)
sw s3, 32(sp)
sw s2, 28(sp)
sw s1, 24(sp)
sw s0, 20(sp)
sw $1, 16(sp)
/* s7 is used as a scratch register. */
mfhi s7
sw s7, 12(sp)
mflo s7
sw s7, 8(sp)
/* Each task maintains its own nesting count. */
la s7, uxCriticalNesting
lw s7, (s7)
sw s7, 4(sp)
/* Update the TCB stack pointer value */
la s7, pxCurrentTCB
lw s7, (s7)
sw sp, (s7)
/* Switch to the ISR stack, saving the current stack in s5. This might
be used to determine the cause of a general exception. */
add s5, zero, sp
la s7, xISRStackTop
lw sp, (s7)
.endm
/******************************************************************/
.macro portRESTORE_CONTEXT
/* Restore the stack pointer from the TCB */
la s0, pxCurrentTCB
lw s1, (s0)
lw sp, (s1)
/* Restore the context, the first item of which is the critical nesting
depth. */
la s0, uxCriticalNesting
lw s1, 4(sp)
sw s1, (s0)
/* Restore the rest of the context. */
lw s0, 8(sp)
mtlo s0
lw s0, 12(sp)
mthi s0
lw $1, 16(sp)
lw s0, 20(sp)
lw s1, 24(sp)
lw s2, 28(sp)
lw s3, 32(sp)
lw s4, 36(sp)
lw s5, 40(sp)
lw s6, 44(sp)
lw s7, 48(sp)
lw v0, 52(sp)
lw v1, 56(sp)
lw a0, 60(sp)
lw a1, 64(sp)
lw a2, 68(sp)
lw a3, 72(sp)
lw t0, 76(sp)
lw t1, 80(sp)
lw t2, 84(sp)
lw t3, 88(sp)
lw t4, 92(sp)
lw t5, 96(sp)
lw t6, 100(sp)
lw t7, 104(sp)
lw t8, 108(sp)
lw t9, 112(sp)
lw s8, 116(sp)
lw ra, 120(sp)
/* Protect access to the k registers. */
di
lw k1, portSTATUS_STACK_LOCATION(sp)
lw k0, portEPC_STACK_LOCATION(sp)
/* Leave the stack how we found it. */
addiu sp, sp, portCONTEXT_SIZE
mtc0 k1, _CP0_STATUS
ehb
mtc0 k0, _CP0_EPC
eret
nop
.endm