mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-08-19 09:38:32 -04:00
Carry on working on the Cortex-A/GCC port layer - still a work in progress.
This commit is contained in:
Richard Barry
parent
33351b02c9
commit
3e430b3801
3 changed files with 209 additions and 189 deletions
|
|
@ -53,40 +53,124 @@
|
|||
*/
|
||||
|
||||
|
||||
.org 0
|
||||
.text
|
||||
|
||||
.set SYS_MODE, 0x1f
|
||||
.set SVC_MODE, 0x13
|
||||
.set IRQ_MODE, 0x12
|
||||
|
||||
.extern _boot
|
||||
.extern vTaskSwitchContext
|
||||
.extern ulICCIAR
|
||||
.extern ulICCEOIR
|
||||
.extern ulMaxAPIPriorityMask
|
||||
.extern ulICCPMR
|
||||
.extern _freertos_vector_table
|
||||
|
||||
.global _vector_table
|
||||
.global FreeRTOS_vector_table
|
||||
.global FIQInterrupt
|
||||
.global Undefined
|
||||
.global PrefetchAbortHandler
|
||||
.global DataAbortInterrupt
|
||||
|
||||
.extern pxCurrentTCB
|
||||
.extern XIntc_DeviceInterruptHandler
|
||||
.extern vTaskSwitchContext
|
||||
.extern uxCriticalNesting
|
||||
.extern pulISRStack
|
||||
.extern ulTaskSwitchRequested
|
||||
.extern vPortExceptionHandler
|
||||
.extern pulStackPointerOnFunctionEntry
|
||||
|
||||
.global FreeRTOS_IRQ_Handler
|
||||
.global FreeRTOS_SWI_Handler
|
||||
.global vPortRestoreTaskContext
|
||||
.global vPortInstallFreeRTOSVectorTable
|
||||
|
||||
|
||||
|
||||
|
||||
.macro portSAVE_CONTEXT
|
||||
|
||||
/* Save the LR and SPSR onto the system mode stack before switching to
|
||||
system mode to save the remaining system mode registers. */
|
||||
SRSDB sp!, #SYS_MODE
|
||||
CPS #SYS_MODE
|
||||
PUSH {R0-R12, R14}
|
||||
|
||||
/* Push the critical nesting count. */
|
||||
LDR R2, =ulCriticalNesting
|
||||
LDR R1, [R2]
|
||||
PUSH {R1}
|
||||
|
||||
/* Does the task have a floating point context that needs saving? If
|
||||
ulPortTaskHasFPUContext is 0 then no. */
|
||||
LDR R2, =ulPortTaskHasFPUContext
|
||||
LDR R3, [R2]
|
||||
CMP R3, #0
|
||||
|
||||
/* Save the floating point context, if any. */
|
||||
FMRXNE R1, FPSCR
|
||||
VPUSHNE {D0-D15}
|
||||
VPUSHNE {D16-D31}
|
||||
PUSHNE {R1}
|
||||
|
||||
/* Save ulPortTaskHasFPUContext itself. */
|
||||
PUSH {R3}
|
||||
|
||||
/* Save the stack pointer in the TCB. */
|
||||
LDR R0, =pxCurrentTCB
|
||||
LDR R1, [R0]
|
||||
STR SP, [R1]
|
||||
|
||||
.endm
|
||||
|
||||
; /**********************************************************************/
|
||||
|
||||
.macro portRESTORE_CONTEXT
|
||||
|
||||
/* Switch to system mode. */
|
||||
CPS #SYS_MODE
|
||||
|
||||
/* Set the SP to point to the stack of the task being restored. */
|
||||
LDR R0, =pxCurrentTCB
|
||||
LDR R1, [R0]
|
||||
LDR SP, [R1]
|
||||
|
||||
/* Is there a floating point context to restore? If the restored
|
||||
ulPortTaskHasFPUContext is zero then no. */
|
||||
LDR R0, =ulPortTaskHasFPUContext
|
||||
POP {R1}
|
||||
STR R1, [R0]
|
||||
CMP R1, #0
|
||||
|
||||
/* Restore the floating point context, if any. */
|
||||
POPNE {R0}
|
||||
VPOPNE {D16-D31}
|
||||
VPOPNE {D0-D15}
|
||||
VMSRNE FPSCR, R0
|
||||
|
||||
/* Restore the critical section nesting depth. */
|
||||
LDR R0, =ulCriticalNesting
|
||||
POP {R1}
|
||||
STR R1, [R0]
|
||||
|
||||
/* Ensure the priority mask is correct for the critical nesting depth. */
|
||||
LDR R2, =ulICCPMR
|
||||
CMP R1, #0
|
||||
MOVEQ R4, #255
|
||||
LDRNE R4, =ulMaxAPIPriorityMask
|
||||
STR R4, [r2]
|
||||
|
||||
/* Restore all system mode registers other than the SP (which is already
|
||||
being used). */
|
||||
POP {R0-R12, R14}
|
||||
|
||||
/* Return to the task code, loading CPSR on the way. */
|
||||
RFEIA sp!
|
||||
|
||||
.endm
|
||||
|
||||
.section .vectors
|
||||
|
||||
_vector_table:
|
||||
B _boot
|
||||
B Undefined
|
||||
ldr pc, _swi
|
||||
B PrefetchAbortHandler
|
||||
B DataAbortHandler
|
||||
NOP /* Placeholder for address exception vector*/
|
||||
LDR PC, _irq
|
||||
B FIQHandler
|
||||
|
||||
_irq: .word FreeRTOS_IRQ_Handler
|
||||
_swi: .word FreeRTOS_SWI_Handler
|
||||
|
||||
/******************************************************************************
|
||||
* SVC handler is used to start the scheduler and yield a task.
|
||||
|
|
@ -94,12 +178,42 @@ _swi: .word FreeRTOS_SWI_Handler
|
|||
FreeRTOS_SWI_Handler:
|
||||
|
||||
/* Save the context of the current task and select a new task to run. */
|
||||
// portSAVE_CONTEXT
|
||||
/* Save the LR and SPSR onto the system mode stack before switching to
|
||||
system mode to save the remaining system mode registers. */
|
||||
SRSDB sp!, #SYS_MODE
|
||||
CPS #SYS_MODE
|
||||
PUSH {R0-R12, R14}
|
||||
|
||||
/* Push the critical nesting count. */
|
||||
LDR R2, =ulCriticalNesting
|
||||
LDR R1, [R2]
|
||||
PUSH {R1}
|
||||
|
||||
/* Does the task have a floating point context that needs saving? If
|
||||
ulPortTaskHasFPUContext is 0 then no. */
|
||||
LDR R2, =ulPortTaskHasFPUContext
|
||||
LDR R3, [R2]
|
||||
CMP R3, #0
|
||||
|
||||
/* Save the floating point context, if any. */
|
||||
FMRXNE R1, FPSCR
|
||||
VPUSHNE {D0-D15}
|
||||
VPUSHNE {D16-D31}
|
||||
PUSHNE {R1}
|
||||
|
||||
/* Save ulPortTaskHasFPUContext itself. */
|
||||
PUSH {R3}
|
||||
|
||||
/* Save the stack pointer in the TCB. */
|
||||
LDR R0, =pxCurrentTCB
|
||||
LDR R1, [R0]
|
||||
STR SP, [R1]
|
||||
|
||||
LDR R0, =vTaskSwitchContext
|
||||
BLX R0
|
||||
|
||||
vPortRestoreTaskContext:
|
||||
// portRESTORE_CONTEXT
|
||||
portRESTORE_CONTEXT
|
||||
|
||||
FreeRTOS_IRQ_Handler:
|
||||
/* Return to the interrupted instruction. */
|
||||
|
|
@ -185,7 +299,7 @@ switch_before_exit:
|
|||
POP {LR}
|
||||
MSR SPSR_cxsf, LR
|
||||
POP {LR}
|
||||
// portSAVE_CONTEXT
|
||||
portSAVE_CONTEXT
|
||||
|
||||
/* Call the function that selects the new task to execute.
|
||||
vTaskSwitchContext() if vTaskSwitchContext() uses LDRD or STRD
|
||||
|
|
@ -195,23 +309,19 @@ switch_before_exit:
|
|||
|
||||
/* Restore the context of, and branch to, the task selected to execute
|
||||
next. */
|
||||
// portRESTORE_CONTEXT
|
||||
portRESTORE_CONTEXT
|
||||
|
||||
ulICCIARConst: .word ulICCIAR
|
||||
ulICCEOIRConst: .word ulICCEOIR
|
||||
|
||||
vPortInstallFreeRTOSVectorTable:
|
||||
/* Set VBAR to the vector table that contains the FreeRTOS handlers. */
|
||||
ldr r0, =_freertos_vector_table
|
||||
mcr p15, 0, r0, c12, c0, 0
|
||||
dsb
|
||||
isb
|
||||
bx lr
|
||||
|
||||
Undefined:
|
||||
B .
|
||||
|
||||
PrefetchAbortHandler:
|
||||
B .
|
||||
|
||||
FIQHandler:
|
||||
B .
|
||||
|
||||
DataAbortHandler:
|
||||
B .
|
||||
|
||||
.end
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue