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/*
* FreeRTOS Kernel V10.4.3 LTS Patch 2
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* 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
*
* 1 tab == 4 spaces!
*/
.text
/* Variables and functions. */
.extern ullMaxAPIPriorityMask
.extern pxCurrentTCB
.extern vTaskSwitchContext
.extern vApplicationIRQHandler
.extern ullPortInterruptNesting
.extern ullPortTaskHasFPUContext
.extern ullCriticalNesting
.extern ullPortYieldRequired
.extern ullICCEOIR
.extern ullICCIAR
.extern _freertos_vector_table
.global FreeRTOS_IRQ_Handler
.global FreeRTOS_SWI_Handler
.global vPortRestoreTaskContext
.macro portSAVE_CONTEXT
/* Switch to use the EL0 stack pointer. */
MSR SPSEL, #0
/* Save the entire context. */
STP X0, X1, [SP, #-0x10]!
STP X2, X3, [SP, #-0x10]!
STP X4, X5, [SP, #-0x10]!
STP X6, X7, [SP, #-0x10]!
STP X8, X9, [SP, #-0x10]!
STP X10, X11, [SP, #-0x10]!
STP X12, X13, [SP, #-0x10]!
STP X14, X15, [SP, #-0x10]!
STP X16, X17, [SP, #-0x10]!
STP X18, X19, [SP, #-0x10]!
STP X20, X21, [SP, #-0x10]!
STP X22, X23, [SP, #-0x10]!
STP X24, X25, [SP, #-0x10]!
STP X26, X27, [SP, #-0x10]!
STP X28, X29, [SP, #-0x10]!
STP X30, XZR, [SP, #-0x10]!
/* Save the SPSR. */
#if defined( GUEST )
MRS X3, SPSR_EL1
MRS X2, ELR_EL1
#else
MRS X3, SPSR_EL3
/* Save the ELR. */
MRS X2, ELR_EL3
#endif
STP X2, X3, [SP, #-0x10]!
/* Save the critical section nesting depth. */
LDR X0, ullCriticalNestingConst
LDR X3, [X0]
/* Save the FPU context indicator. */
LDR X0, ullPortTaskHasFPUContextConst
LDR X2, [X0]
/* Save the FPU context, if any (32 128-bit registers). */
CMP X2, #0
B.EQ 1f
STP Q0, Q1, [SP,#-0x20]!
STP Q2, Q3, [SP,#-0x20]!
STP Q4, Q5, [SP,#-0x20]!
STP Q6, Q7, [SP,#-0x20]!
STP Q8, Q9, [SP,#-0x20]!
STP Q10, Q11, [SP,#-0x20]!
STP Q12, Q13, [SP,#-0x20]!
STP Q14, Q15, [SP,#-0x20]!
STP Q16, Q17, [SP,#-0x20]!
STP Q18, Q19, [SP,#-0x20]!
STP Q20, Q21, [SP,#-0x20]!
STP Q22, Q23, [SP,#-0x20]!
STP Q24, Q25, [SP,#-0x20]!
STP Q26, Q27, [SP,#-0x20]!
STP Q28, Q29, [SP,#-0x20]!
STP Q30, Q31, [SP,#-0x20]!
1:
/* Store the critical nesting count and FPU context indicator. */
STP X2, X3, [SP, #-0x10]!
LDR X0, pxCurrentTCBConst
LDR X1, [X0]
MOV X0, SP /* Move SP into X0 for saving. */
STR X0, [X1]
/* Switch to use the ELx stack pointer. */
MSR SPSEL, #1
.endm
; /**********************************************************************/
.macro portRESTORE_CONTEXT
/* Switch to use the EL0 stack pointer. */
MSR SPSEL, #0
/* Set the SP to point to the stack of the task being restored. */
LDR X0, pxCurrentTCBConst
LDR X1, [X0]
LDR X0, [X1]
MOV SP, X0
LDP X2, X3, [SP], #0x10 /* Critical nesting and FPU context. */
/* Set the PMR register to be correct for the current critical nesting
depth. */
LDR X0, ullCriticalNestingConst /* X0 holds the address of ullCriticalNesting. */
MOV X1, #255 /* X1 holds the unmask value. */
LDR X4, ullICCPMRConst /* X4 holds the address of the ICCPMR constant. */
CMP X3, #0
LDR X5, [X4] /* X5 holds the address of the ICCPMR register. */
B.EQ 1f
LDR X6, ullMaxAPIPriorityMaskConst
LDR X1, [X6] /* X1 holds the mask value. */
1:
STR W1, [X5] /* Write the mask value to ICCPMR. */
DSB SY /* _RB_Barriers probably not required here. */
ISB SY
STR X3, [X0] /* Restore the task's critical nesting count. */
/* Restore the FPU context indicator. */
LDR X0, ullPortTaskHasFPUContextConst
STR X2, [X0]
/* Restore the FPU context, if any. */
CMP X2, #0
B.EQ 1f
LDP Q30, Q31, [SP], #0x20
LDP Q28, Q29, [SP], #0x20
LDP Q26, Q27, [SP], #0x20
LDP Q24, Q25, [SP], #0x20
LDP Q22, Q23, [SP], #0x20
LDP Q20, Q21, [SP], #0x20
LDP Q18, Q19, [SP], #0x20
LDP Q16, Q17, [SP], #0x20
LDP Q14, Q15, [SP], #0x20
LDP Q12, Q13, [SP], #0x20
LDP Q10, Q11, [SP], #0x20
LDP Q8, Q9, [SP], #0x20
LDP Q6, Q7, [SP], #0x20
LDP Q4, Q5, [SP], #0x20
LDP Q2, Q3, [SP], #0x20
LDP Q0, Q1, [SP], #0x20
1:
LDP X2, X3, [SP], #0x10 /* SPSR and ELR. */
#if defined( GUEST )
/* Restore the SPSR. */
MSR SPSR_EL1, X3
/* Restore the ELR. */
MSR ELR_EL1, X2
#else
/* Restore the SPSR. */
MSR SPSR_EL3, X3 /*_RB_ Assumes started in EL3. */
/* Restore the ELR. */
MSR ELR_EL3, X2
#endif
LDP X30, XZR, [SP], #0x10
LDP X28, X29, [SP], #0x10
LDP X26, X27, [SP], #0x10
LDP X24, X25, [SP], #0x10
LDP X22, X23, [SP], #0x10
LDP X20, X21, [SP], #0x10
LDP X18, X19, [SP], #0x10
LDP X16, X17, [SP], #0x10
LDP X14, X15, [SP], #0x10
LDP X12, X13, [SP], #0x10
LDP X10, X11, [SP], #0x10
LDP X8, X9, [SP], #0x10
LDP X6, X7, [SP], #0x10
LDP X4, X5, [SP], #0x10
LDP X2, X3, [SP], #0x10
LDP X0, X1, [SP], #0x10
/* Switch to use the ELx stack pointer. _RB_ Might not be required. */
MSR SPSEL, #1
ERET
.endm
/******************************************************************************
* FreeRTOS_SWI_Handler handler is used to perform a context switch.
*****************************************************************************/
.align 8
.type FreeRTOS_SWI_Handler, %function
FreeRTOS_SWI_Handler:
/* Save the context of the current task and select a new task to run. */
portSAVE_CONTEXT
#if defined( GUEST )
MRS X0, ESR_EL1
#else
MRS X0, ESR_EL3
#endif
LSR X1, X0, #26
#if defined( GUEST )
CMP X1, #0x15 /* 0x15 = SVC instruction. */
#else
CMP X1, #0x17 /* 0x17 = SMC instruction. */
#endif
B.NE FreeRTOS_Abort
BL vTaskSwitchContext
portRESTORE_CONTEXT
FreeRTOS_Abort:
/* Full ESR is in X0, exception class code is in X1. */
B .
/******************************************************************************
* vPortRestoreTaskContext is used to start the scheduler.
*****************************************************************************/
.align 8
.type vPortRestoreTaskContext, %function
vPortRestoreTaskContext:
.set freertos_vector_base, _freertos_vector_table
/* Install the FreeRTOS interrupt handlers. */
LDR X1, =freertos_vector_base
#if defined( GUEST )
MSR VBAR_EL1, X1
#else
MSR VBAR_EL3, X1
#endif
DSB SY
ISB SY
/* Start the first task. */
portRESTORE_CONTEXT
/******************************************************************************
* FreeRTOS_IRQ_Handler handles IRQ entry and exit.
*****************************************************************************/
.align 8
.type FreeRTOS_IRQ_Handler, %function
FreeRTOS_IRQ_Handler:
/* Save volatile registers. */
STP X0, X1, [SP, #-0x10]!
STP X2, X3, [SP, #-0x10]!
STP X4, X5, [SP, #-0x10]!
STP X6, X7, [SP, #-0x10]!
STP X8, X9, [SP, #-0x10]!
STP X10, X11, [SP, #-0x10]!
STP X12, X13, [SP, #-0x10]!
STP X14, X15, [SP, #-0x10]!
STP X16, X17, [SP, #-0x10]!
STP X18, X19, [SP, #-0x10]!
STP X29, X30, [SP, #-0x10]!
/* Save the SPSR and ELR. */
#if defined( GUEST )
MRS X3, SPSR_EL1
MRS X2, ELR_EL1
#else
MRS X3, SPSR_EL3
MRS X2, ELR_EL3
#endif
STP X2, X3, [SP, #-0x10]!
/* Increment the interrupt nesting counter. */
LDR X5, ullPortInterruptNestingConst
LDR X1, [X5] /* Old nesting count in X1. */
ADD X6, X1, #1
STR X6, [X5] /* Address of nesting count variable in X5. */
/* Maintain the interrupt nesting information across the function call. */
STP X1, X5, [SP, #-0x10]!
/* Read value from the interrupt acknowledge register, which is stored in W0
for future parameter and interrupt clearing use. */
LDR X2, ullICCIARConst
LDR X3, [X2]
LDR W0, [X3] /* ICCIAR in W0 as parameter. */
/* Maintain the ICCIAR value across the function call. */
STP X0, X1, [SP, #-0x10]!
/* Call the C handler. */
BL vApplicationIRQHandler
/* Disable interrupts. */
MSR DAIFSET, #2
DSB SY
ISB SY
/* Restore the ICCIAR value. */
LDP X0, X1, [SP], #0x10
/* End IRQ processing by writing ICCIAR to the EOI register. */
LDR X4, ullICCEOIRConst
LDR X4, [X4]
STR W0, [X4]
/* Restore the critical nesting count. */
LDP X1, X5, [SP], #0x10
STR X1, [X5]
/* Has interrupt nesting unwound? */
CMP X1, #0
B.NE Exit_IRQ_No_Context_Switch
/* Is a context switch required? */
LDR X0, ullPortYieldRequiredConst
LDR X1, [X0]
CMP X1, #0
B.EQ Exit_IRQ_No_Context_Switch
/* Reset ullPortYieldRequired to 0. */
MOV X2, #0
STR X2, [X0]
/* Restore volatile registers. */
LDP X4, X5, [SP], #0x10 /* SPSR and ELR. */
#if defined( GUEST )
MSR SPSR_EL1, X5
MSR ELR_EL1, X4
#else
MSR SPSR_EL3, X5 /*_RB_ Assumes started in EL3. */
MSR ELR_EL3, X4
#endif
DSB SY
ISB SY
LDP X29, X30, [SP], #0x10
LDP X18, X19, [SP], #0x10
LDP X16, X17, [SP], #0x10
LDP X14, X15, [SP], #0x10
LDP X12, X13, [SP], #0x10
LDP X10, X11, [SP], #0x10
LDP X8, X9, [SP], #0x10
LDP X6, X7, [SP], #0x10
LDP X4, X5, [SP], #0x10
LDP X2, X3, [SP], #0x10
LDP X0, X1, [SP], #0x10
/* Save the context of the current task and select a new task to run. */
portSAVE_CONTEXT
BL vTaskSwitchContext
portRESTORE_CONTEXT
Exit_IRQ_No_Context_Switch:
/* Restore volatile registers. */
LDP X4, X5, [SP], #0x10 /* SPSR and ELR. */
#if defined( GUEST )
MSR SPSR_EL1, X5
MSR ELR_EL1, X4
#else
MSR SPSR_EL3, X5 /*_RB_ Assumes started in EL3. */
MSR ELR_EL3, X4
#endif
DSB SY
ISB SY
LDP X29, X30, [SP], #0x10
LDP X18, X19, [SP], #0x10
LDP X16, X17, [SP], #0x10
LDP X14, X15, [SP], #0x10
LDP X12, X13, [SP], #0x10
LDP X10, X11, [SP], #0x10
LDP X8, X9, [SP], #0x10
LDP X6, X7, [SP], #0x10
LDP X4, X5, [SP], #0x10
LDP X2, X3, [SP], #0x10
LDP X0, X1, [SP], #0x10
ERET
.align 8
pxCurrentTCBConst: .dword pxCurrentTCB
ullCriticalNestingConst: .dword ullCriticalNesting
ullPortTaskHasFPUContextConst: .dword ullPortTaskHasFPUContext
ullICCPMRConst: .dword ullICCPMR
ullMaxAPIPriorityMaskConst: .dword ullMaxAPIPriorityMask
vApplicationIRQHandlerConst: .word vApplicationIRQHandler
ullPortInterruptNestingConst: .dword ullPortInterruptNesting
ullPortYieldRequiredConst: .dword ullPortYieldRequired
ullICCIARConst: .dword ullICCIAR
ullICCEOIRConst: .dword ullICCEOIR
.end
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