/*
* FreeRTOS Kernel <DEVELOPMENT BRANCH>
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/* FreeRTOS includes. */
#include "FreeRTOSConfig.h"
/* Xilinx library includes. */
#include "microblaze_exceptions_g.h"
#include "xparameters.h"
/* The context is oversized to allow functions called from the ISR to write
back into the caller stack. */
#if( XPAR_MICROBLAZE_USE_FPU != 0 )
#define portCONTEXT_SIZE 136
#define portMINUS_CONTEXT_SIZE -136
#else
#define portCONTEXT_SIZE 132
#define portMINUS_CONTEXT_SIZE -132
#endif
/* Offsets from the stack pointer at which saved registers are placed. */
#define portR31_OFFSET 4
#define portR30_OFFSET 8
#define portR29_OFFSET 12
#define portR28_OFFSET 16
#define portR27_OFFSET 20
#define portR26_OFFSET 24
#define portR25_OFFSET 28
#define portR24_OFFSET 32
#define portR23_OFFSET 36
#define portR22_OFFSET 40
#define portR21_OFFSET 44
#define portR20_OFFSET 48
#define portR19_OFFSET 52
#define portR18_OFFSET 56
#define portR17_OFFSET 60
#define portR16_OFFSET 64
#define portR15_OFFSET 68
#define portR14_OFFSET 72
#define portR13_OFFSET 76
#define portR12_OFFSET 80
#define portR11_OFFSET 84
#define portR10_OFFSET 88
#define portR9_OFFSET 92
#define portR8_OFFSET 96
#define portR7_OFFSET 100
#define portR6_OFFSET 104
#define portR5_OFFSET 108
#define portR4_OFFSET 112
#define portR3_OFFSET 116
#define portR2_OFFSET 120
#define portCRITICAL_NESTING_OFFSET 124
#define portMSR_OFFSET 128
#define portFSR_OFFSET 132
.extern pxCurrentTCB
.extern XIntc_DeviceInterruptHandler
.extern vTaskSwitchContext
.extern uxCriticalNesting
.extern pulISRStack
.extern ulTaskSwitchRequested
.extern vPortExceptionHandler
.extern pulStackPointerOnFunctionEntry
.global _interrupt_handler
.global VPortYieldASM
.global vPortStartFirstTask
.global vPortExceptionHandlerEntry
.macro portSAVE_CONTEXT
/* Make room for the context on the stack. */
addik r1, r1, portMINUS_CONTEXT_SIZE
/* Stack general registers. */
swi r31, r1, portR31_OFFSET
swi r30, r1, portR30_OFFSET
swi r29, r1, portR29_OFFSET
swi r28, r1, portR28_OFFSET
swi r27, r1, portR27_OFFSET
swi r26, r1, portR26_OFFSET
swi r25, r1, portR25_OFFSET
swi r24, r1, portR24_OFFSET
swi r23, r1, portR23_OFFSET
swi r22, r1, portR22_OFFSET
swi r21, r1, portR21_OFFSET
swi r20, r1, portR20_OFFSET
swi r19, r1, portR19_OFFSET
swi r18, r1, portR18_OFFSET
swi r17, r1, portR17_OFFSET
swi r16, r1, portR16_OFFSET
swi r15, r1, portR15_OFFSET
/* R14 is saved later as it needs adjustment if a yield is performed. */
swi r13, r1, portR13_OFFSET
swi r12, r1, portR12_OFFSET
swi r11, r1, portR11_OFFSET
swi r10, r1, portR10_OFFSET
swi r9, r1, portR9_OFFSET
swi r8, r1, portR8_OFFSET
swi r7, r1, portR7_OFFSET
swi r6, r1, portR6_OFFSET
swi r5, r1, portR5_OFFSET
swi r4, r1, portR4_OFFSET
swi r3, r1, portR3_OFFSET
swi r2, r1, portR2_OFFSET
/* Stack the critical section nesting value. */
lwi r18, r0, uxCriticalNesting
swi r18, r1, portCRITICAL_NESTING_OFFSET
/* Stack MSR. */
mfs r18, rmsr
swi r18, r1, portMSR_OFFSET
#if( XPAR_MICROBLAZE_USE_FPU != 0 )
/* Stack FSR. */
mfs r18, rfsr
swi r18, r1, portFSR_OFFSET
#endif
/* Save the top of stack value to the TCB. */
lwi r3, r0, pxCurrentTCB
sw r1, r0, r3
.endm
.macro portRESTORE_CONTEXT
/* Load the top of stack value from the TCB. */
lwi r18, r0, pxCurrentTCB
lw r1, r0, r18
/* Restore the general registers. */
lwi r31, r1, portR31_OFFSET
lwi r30, r1, portR30_OFFSET
lwi r29, r1, portR29_OFFSET
lwi r28, r1, portR28_OFFSET
lwi r27, r1, portR27_OFFSET
lwi r26, r1, portR26_OFFSET
lwi r25, r1, portR25_OFFSET
lwi r24, r1, portR24_OFFSET
lwi r23, r1, portR23_OFFSET
lwi r22, r1, portR22_OFFSET
lwi r21, r1, portR21_OFFSET
lwi r20, r1, portR20_OFFSET
lwi r19, r1, portR19_OFFSET
lwi r17, r1, portR17_OFFSET
lwi r16, r1, portR16_OFFSET
lwi r15, r1, portR15_OFFSET
lwi r14, r1, portR14_OFFSET
lwi r13, r1, portR13_OFFSET
lwi r12, r1, portR12_OFFSET
lwi r11, r1, portR11_OFFSET
lwi r10, r1, portR10_OFFSET
lwi r9, r1, portR9_OFFSET
lwi r8, r1, portR8_OFFSET
lwi r7, r1, portR7_OFFSET
lwi r6, r1, portR6_OFFSET
lwi r5, r1, portR5_OFFSET
lwi r4, r1, portR4_OFFSET
lwi r3, r1, portR3_OFFSET
lwi r2, r1, portR2_OFFSET
/* Reload the rmsr from the stack. */
lwi r18, r1, portMSR_OFFSET
mts rmsr, r18
#if( XPAR_MICROBLAZE_USE_FPU != 0 )
/* Reload the FSR from the stack. */
lwi r18, r1, portFSR_OFFSET
mts rfsr, r18
#endif
/* Load the critical nesting value. */
lwi r18, r1, portCRITICAL_NESTING_OFFSET
swi r18, r0, uxCriticalNesting
/* Test the critical nesting value. If it is non zero then the task last
exited the running state using a yield. If it is zero, then the task
last exited the running state through an interrupt. */
xori r18, r18, 0
bnei r18, exit_from_yield
/* r18 was being used as a temporary. Now restore its true value from the
stack. */
lwi r18, r1, portR18_OFFSET
/* Remove the stack frame. */
addik r1, r1, portCONTEXT_SIZE
/* Return using rtid so interrupts are re-enabled as this function is
exited. */
rtid r14, 0
or r0, r0, r0
.endm
/* This function is used to exit portRESTORE_CONTEXT() if the task being
returned to last left the Running state by calling taskYIELD() (rather than
being preempted by an interrupt). */
.text
.align 4
exit_from_yield:
/* r18 was being used as a temporary. Now restore its true value from the
stack. */
lwi r18, r1, portR18_OFFSET
/* Remove the stack frame. */
addik r1, r1, portCONTEXT_SIZE
/* Return to the task. */
rtsd r14, 0
or r0, r0, r0
.text
.align 4
_interrupt_handler:
portSAVE_CONTEXT
/* Stack the return address. */
swi r14, r1, portR14_OFFSET
/* Switch to the ISR stack. */
lwi r1, r0, pulISRStack
/* The parameter to the interrupt handler. */
ori r5, r0, configINTERRUPT_CONTROLLER_TO_USE
/* Execute any pending interrupts. */
bralid r15, XIntc_DeviceInterruptHandler
or r0, r0, r0
/* See if a new task should be selected to execute. */
lwi r18, r0, ulTaskSwitchRequested
or r18, r18, r0
/* If ulTaskSwitchRequested is already zero, then jump straight to
restoring the task that is already in the Running state. */
beqi r18, task_switch_not_requested
/* Set ulTaskSwitchRequested back to zero as a task switch is about to be
performed. */
swi r0, r0, ulTaskSwitchRequested
/* ulTaskSwitchRequested was not 0 when tested. Select the next task to
execute. */
bralid r15, vTaskSwitchContext
or r0, r0, r0
task_switch_not_requested:
/* Restore the context of the next task scheduled to execute. */
portRESTORE_CONTEXT
.text
.align 4
VPortYieldASM:
portSAVE_CONTEXT
/* Modify the return address so a return is done to the instruction after
the call to VPortYieldASM. */
addi r14, r14, 8
swi r14, r1, portR14_OFFSET
/* Switch to use the ISR stack. */
lwi r1, r0, pulISRStack
/* Select the next task to execute. */
bralid r15, vTaskSwitchContext
or r0, r0, r0
/* Restore the context of the next task scheduled to execute. */
portRESTORE_CONTEXT
.text
.align 4
vPortStartFirstTask:
portRESTORE_CONTEXT
#if ( MICROBLAZE_EXCEPTIONS_ENABLED == 1 ) && ( configINSTALL_EXCEPTION_HANDLERS == 1 )
.text
.align 4
vPortExceptionHandlerEntry:
/* Take a copy of the stack pointer before vPortExecptionHandler is called,
storing its value prior to the function stack frame being created. */
swi r1, r0, pulStackPointerOnFunctionEntry
bralid r15, vPortExceptionHandler
or r0, r0, r0
#endif /* ( MICROBLAZE_EXCEPTIONS_ENABLED == 1 ) && ( configINSTALL_EXCEPTION_HANDLERS == 1 ) */