242 lines
6.3 KiB
ArmAsm
242 lines
6.3 KiB
ArmAsm
;/*
|
|
; * File : context_rvds.S
|
|
; * This file is part of RT-Thread RTOS
|
|
; * COPYRIGHT (C) 2009, RT-Thread Development Team
|
|
; *
|
|
; * The license and distribution terms for this file may be
|
|
; * found in the file LICENSE in this distribution or at
|
|
; * http://www.rt-thread.org/license/LICENSE
|
|
; *
|
|
; * Change Logs:
|
|
; * Date Author Notes
|
|
; * 2009-01-17 Bernard first version.
|
|
; * 2012-01-01 aozima support context switch load/store FPU register.
|
|
; * 2013-06-18 aozima add restore MSP feature.
|
|
; * 2013-06-23 aozima support lazy stack optimized.
|
|
; */
|
|
|
|
;/**
|
|
; * @addtogroup cortex-m4
|
|
; */
|
|
;/*@{*/
|
|
|
|
SCB_VTOR EQU 0xE000ED08 ; Vector Table Offset Register
|
|
NVIC_INT_CTRL EQU 0xE000ED04 ; interrupt control state register
|
|
NVIC_SYSPRI2 EQU 0xE000ED20 ; system priority register (2)
|
|
NVIC_PENDSV_PRI EQU 0x00FF0000 ; PendSV priority value (lowest)
|
|
NVIC_PENDSVSET EQU 0x10000000 ; value to trigger PendSV exception
|
|
|
|
AREA |.text|, CODE, READONLY, ALIGN=2
|
|
THUMB
|
|
REQUIRE8
|
|
PRESERVE8
|
|
|
|
IMPORT rt_thread_switch_interrupt_flag
|
|
IMPORT rt_interrupt_from_thread
|
|
IMPORT rt_interrupt_to_thread
|
|
|
|
;/*
|
|
; * rt_base_t rt_hw_interrupt_disable();
|
|
; */
|
|
rt_hw_interrupt_disable PROC
|
|
EXPORT rt_hw_interrupt_disable
|
|
MRS r0, PRIMASK
|
|
CPSID I
|
|
BX LR
|
|
ENDP
|
|
|
|
;/*
|
|
; * void rt_hw_interrupt_enable(rt_base_t level);
|
|
; */
|
|
rt_hw_interrupt_enable PROC
|
|
EXPORT rt_hw_interrupt_enable
|
|
MSR PRIMASK, r0
|
|
BX LR
|
|
ENDP
|
|
|
|
;/*
|
|
; * void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
|
|
; * r0 --> from
|
|
; * r1 --> to
|
|
; */
|
|
rt_hw_context_switch_interrupt
|
|
EXPORT rt_hw_context_switch_interrupt
|
|
rt_hw_context_switch PROC
|
|
EXPORT rt_hw_context_switch
|
|
|
|
; set rt_thread_switch_interrupt_flag to 1
|
|
LDR r2, =rt_thread_switch_interrupt_flag
|
|
LDR r3, [r2]
|
|
CMP r3, #1
|
|
BEQ _reswitch
|
|
MOV r3, #1
|
|
STR r3, [r2]
|
|
|
|
LDR r2, =rt_interrupt_from_thread ; set rt_interrupt_from_thread
|
|
STR r0, [r2]
|
|
|
|
_reswitch
|
|
LDR r2, =rt_interrupt_to_thread ; set rt_interrupt_to_thread
|
|
STR r1, [r2]
|
|
|
|
LDR r0, =NVIC_INT_CTRL ; trigger the PendSV exception (causes context switch)
|
|
LDR r1, =NVIC_PENDSVSET
|
|
STR r1, [r0]
|
|
BX LR
|
|
ENDP
|
|
|
|
; r0 --> switch from thread stack
|
|
; r1 --> switch to thread stack
|
|
; psr, pc, lr, r12, r3, r2, r1, r0 are pushed into [from] stack
|
|
PendSV_Handler PROC
|
|
EXPORT PendSV_Handler
|
|
|
|
; disable interrupt to protect context switch
|
|
MRS r2, PRIMASK
|
|
CPSID I
|
|
|
|
; get rt_thread_switch_interrupt_flag
|
|
LDR r0, =rt_thread_switch_interrupt_flag
|
|
LDR r1, [r0]
|
|
CBZ r1, pendsv_exit ; pendsv already handled
|
|
|
|
; clear rt_thread_switch_interrupt_flag to 0
|
|
MOV r1, #0x00
|
|
STR r1, [r0]
|
|
|
|
LDR r0, =rt_interrupt_from_thread
|
|
LDR r1, [r0]
|
|
CBZ r1, switch_to_thread ; skip register save at the first time
|
|
|
|
MRS r1, psp ; get from thread stack pointer
|
|
|
|
IF {FPU} != "SoftVFP"
|
|
TST lr, #0x10 ; if(!EXC_RETURN[4])
|
|
VSTMFDEQ r1!, {d8 - d15} ; push FPU register s16~s31
|
|
ENDIF
|
|
|
|
STMFD r1!, {r4 - r11} ; push r4 - r11 register
|
|
|
|
IF {FPU} != "SoftVFP"
|
|
MOV r4, #0x00 ; flag = 0
|
|
|
|
TST lr, #0x10 ; if(!EXC_RETURN[4])
|
|
MOVEQ r4, #0x01 ; flag = 1
|
|
|
|
STMFD r1!, {r4} ; push flag
|
|
ENDIF
|
|
|
|
LDR r0, [r0]
|
|
STR r1, [r0] ; update from thread stack pointer
|
|
|
|
switch_to_thread
|
|
LDR r1, =rt_interrupt_to_thread
|
|
LDR r1, [r1]
|
|
LDR r1, [r1] ; load thread stack pointer
|
|
|
|
IF {FPU} != "SoftVFP"
|
|
LDMFD r1!, {r3} ; pop flag
|
|
ENDIF
|
|
|
|
LDMFD r1!, {r4 - r11} ; pop r4 - r11 register
|
|
|
|
IF {FPU} != "SoftVFP"
|
|
CMP r3, #0 ; if(flag_r3 != 0)
|
|
VLDMFDNE r1!, {d8 - d15} ; pop FPU register s16~s31
|
|
ENDIF
|
|
|
|
MSR psp, r1 ; update stack pointer
|
|
|
|
IF {FPU} != "SoftVFP"
|
|
ORR lr, lr, #0x10 ; lr |= (1 << 4), clean FPCA.
|
|
CMP r3, #0 ; if(flag_r3 != 0)
|
|
BICNE lr, lr, #0x10 ; lr &= ~(1 << 4), set FPCA.
|
|
ENDIF
|
|
|
|
pendsv_exit
|
|
; restore interrupt
|
|
MSR PRIMASK, r2
|
|
|
|
ORR lr, lr, #0x04
|
|
BX lr
|
|
ENDP
|
|
|
|
;/*
|
|
; * void rt_hw_context_switch_to(rt_uint32 to);
|
|
; * r0 --> to
|
|
; * this fucntion is used to perform the first thread switch
|
|
; */
|
|
rt_hw_context_switch_to PROC
|
|
EXPORT rt_hw_context_switch_to
|
|
; set to thread
|
|
LDR r1, =rt_interrupt_to_thread
|
|
STR r0, [r1]
|
|
|
|
IF {FPU} != "SoftVFP"
|
|
; CLEAR CONTROL.FPCA
|
|
MRS r2, CONTROL ; read
|
|
BIC r2, #0x04 ; modify
|
|
MSR CONTROL, r2 ; write-back
|
|
ENDIF
|
|
|
|
; set from thread to 0
|
|
LDR r1, =rt_interrupt_from_thread
|
|
MOV r0, #0x0
|
|
STR r0, [r1]
|
|
|
|
; set interrupt flag to 1
|
|
LDR r1, =rt_thread_switch_interrupt_flag
|
|
MOV r0, #1
|
|
STR r0, [r1]
|
|
|
|
; set the PendSV exception priority
|
|
LDR r0, =NVIC_SYSPRI2
|
|
LDR r1, =NVIC_PENDSV_PRI
|
|
LDR.W r2, [r0,#0x00] ; read
|
|
ORR r1,r1,r2 ; modify
|
|
STR r1, [r0] ; write-back
|
|
|
|
; trigger the PendSV exception (causes context switch)
|
|
LDR r0, =NVIC_INT_CTRL
|
|
LDR r1, =NVIC_PENDSVSET
|
|
STR r1, [r0]
|
|
|
|
; restore MSP
|
|
LDR r0, =SCB_VTOR
|
|
LDR r0, [r0]
|
|
LDR r0, [r0]
|
|
MSR msp, r0
|
|
|
|
; enable interrupts at processor level
|
|
CPSIE F
|
|
CPSIE I
|
|
|
|
; never reach here!
|
|
ENDP
|
|
|
|
; compatible with old version
|
|
rt_hw_interrupt_thread_switch PROC
|
|
EXPORT rt_hw_interrupt_thread_switch
|
|
BX lr
|
|
ENDP
|
|
|
|
IMPORT rt_hw_hard_fault_exception
|
|
EXPORT HardFault_Handler
|
|
EXPORT MemManage_Handler
|
|
HardFault_Handler PROC
|
|
MemManage_Handler
|
|
|
|
; get current context
|
|
MRS r0, psp ; get fault thread stack pointer
|
|
PUSH {lr}
|
|
BL rt_hw_hard_fault_exception
|
|
POP {lr}
|
|
|
|
ORR lr, lr, #0x04
|
|
BX lr
|
|
ENDP
|
|
|
|
ALIGN 4
|
|
|
|
END
|