/*
* Copyright (c) 2006-2024, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2024-03-01 Wangyuqiang first version
*/
#include "rtconfig.h"
.syntax unified
.text
.globl rt_thread_switch_interrupt_flag
.globl rt_interrupt_from_thread
.globl rt_interrupt_to_thread
.globl rt_interrupt_enter
.globl rt_interrupt_leave
.globl rt_hw_trap_irq
/*
* rt_base_t rt_hw_interrupt_disable();
*/
.globl rt_hw_interrupt_disable
rt_hw_interrupt_disable:
mrs r0, cpsr
cpsid i
bx lr
/*
* void rt_hw_interrupt_enable(rt_base_t level);
*/
.globl rt_hw_interrupt_enable
rt_hw_interrupt_enable:
msr cpsr, r0
bx lr
/*
* void rt_hw_context_switch(rt_uint32 from, rt_uint32 to)
* r0 --> from
* r1 --> to
*/
.globl rt_hw_context_switch
rt_hw_context_switch:
clrex
stmfd sp!, {lr} @ push pc (lr should be pushed in place of PC)
stmfd sp!, {r0-r12, lr} @ push lr & register file
mrs r4, cpsr
tst lr, #0x01
orrne r4, r4, #0x20 @ it's thumb code
stmfd sp!, {r4} @ push cpsr
#ifdef RT_USING_FPU
/* fpu context */
vmrs r6, fpexc
tst r6, #(1<<30)
beq __no_vfp_frame1
vstmdb sp!, {d0-d15}
vstmdb sp!, {d16-d31}
vmrs r5, fpscr
stmfd sp!, {r5}
__no_vfp_frame1:
stmfd sp!, {r6}
#endif
str sp, [r0] @ store sp in preempted tasks TCB
ldr sp, [r1] @ get new task stack pointer
#ifdef RT_USING_FPU
/* fpu context */
ldmfd sp!, {r6}
vmsr fpexc, r6
tst r6, #(1<<30)
beq __no_vfp_frame2
ldmfd sp!, {r5}
vmsr fpscr, r5
vldmia sp!, {d16-d31}
vldmia sp!, {d0-d15}
__no_vfp_frame2:
#endif
ldmfd sp!, {r1}
msr spsr_cxsf, r1 /* original mode */
ldmfd sp!, {r0-r12,lr,pc}^ /* irq return */
/*
* void rt_hw_context_switch_to(rt_uint32 to)
* r0 --> to
*/
.globl rt_hw_context_switch_to
rt_hw_context_switch_to:
LDR sp, [r0] @ get new task stack pointer
#ifdef RT_USING_FPU
ldmfd sp!, {r6}
vmsr fpexc, r6
tst r6, #(1<<30)
beq __no_vfp_frame_to
ldmfd sp!, {r5}
vmsr fpscr, r5
vldmia sp!, {d0-d15}
__no_vfp_frame_to:
#endif
LDMIA sp!, {r4} @ pop new task cpsr to spsr
MSR spsr_cxsf, r4
ldmfd sp!, {r0-r12,lr,pc}^ /* irq return */
/*
* void rt_hw_context_switch_interrupt(rt_uint32 from, rt_uint32 to)@
*/
.globl rt_hw_context_switch_interrupt
rt_hw_context_switch_interrupt:
LDR r2, =rt_thread_switch_interrupt_flag
LDR r3, [r2]
CMP r3, #1
BEQ _reswitch
MOV r3, #1 @ set rt_thread_switch_interrupt_flag to 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]
BX lr
.globl IRQ_Handler
IRQ_Handler:
STMDB sp!, {r0-r12,lr}
#ifdef RT_USING_FPU
VMRS r0, fpexc
TST r0, #0x40000000
BEQ __no_vfp_frame_str_irq
VSTMDB sp!, {d0-d15}
VMRS r1, fpscr
@ TODO: add support for Common VFPv3.
@ Save registers like FPINST, FPINST2
STMDB sp!, {r1}
__no_vfp_frame_str_irq:
STMDB sp!, {r0}
#endif
BL rt_interrupt_enter
BL rt_hw_trap_irq
BL rt_interrupt_leave
@ if rt_thread_switch_interrupt_flag set, jump to
@ rt_hw_context_switch_interrupt_do and don't return
LDR r0, =rt_thread_switch_interrupt_flag
LDR r1, [r0]
CMP r1, #1
BEQ rt_hw_context_switch_interrupt_do
#ifdef RT_USING_FPU
LDMIA sp!, {r0} @ get fpexc
VMSR fpexc, r0
TST r0, #0x40000000
BEQ __no_vfp_frame_ldr_irq
LDMIA sp!, {r1} @ get fpscr
VMSR fpscr, r1
VLDMIA sp!, {d0-d15}
__no_vfp_frame_ldr_irq:
#endif
LDMIA sp!, {r0-r12,lr}
SUBS pc, lr, #4
/*
* void rt_hw_context_switch_interrupt_do(rt_base_t flag)
*/
.globl rt_hw_context_switch_interrupt_do
rt_hw_context_switch_interrupt_do:
MOV r1, #0 @ clear flag
STR r1, [r0]
#ifdef RT_USING_FPU
LDMIA sp!, {r0} @ get fpexc
VMSR fpexc, r0
TST r0, #0x40000000
BEQ __no_vfp_frame_do1
LDMIA sp!, {r1} @ get fpscr
VMSR fpscr, r1
VLDMIA sp!, {d0-d15}
__no_vfp_frame_do1:
#endif
LDMIA sp!, {r0-r12,lr} @ reload saved registers
STMDB sp, {r0-r3} @ save r0-r3. We will restore r0-r3 in the SVC
@ mode so there is no need to update SP.
SUB r1, sp, #16 @ save the right SP value in r1, so we could restore r0-r3.
SUB r2, lr, #4 @ save old task's pc to r2
MRS r3, spsr @ get cpsr of interrupt thread
@ switch to SVC mode and no interrupt
CPSID IF, #0x13
STMDB sp!, {r2} @ push old task's pc
STMDB sp!, {r4-r12,lr} @ push old task's lr,r12-r4
LDMIA r1!, {r4-r7} @ restore r0-r3 of the interrupted thread
STMDB sp!, {r4-r7} @ push old task's r3-r0. We don't need to push/pop them to
@ r0-r3 because we just want to transfer the data and don't
@ use them here.
STMDB sp!, {r3} @ push old task's cpsr
#ifdef RT_USING_FPU
VMRS r0, fpexc
TST r0, #0x40000000
BEQ __no_vfp_frame_do2
VSTMDB sp!, {d0-d15}
VMRS r1, fpscr
@ TODO: add support for Common VFPv3.
@ Save registers like FPINST, FPINST2
STMDB sp!, {r1}
__no_vfp_frame_do2:
STMDB sp!, {r0}
#endif
LDR r4, =rt_interrupt_from_thread
LDR r5, [r4]
STR sp, [r5] @ store sp in preempted tasks's TCB
LDR r6, =rt_interrupt_to_thread
LDR r6, [r6]
LDR sp, [r6] @ get new task's stack pointer
#ifdef RT_USING_FPU
ldmfd sp!, {r6}
vmsr fpexc, r6
tst r6, #(1<<30)
beq __no_vfp_frame_do3
ldmfd sp!, {r5}
vmsr fpscr, r5
vldmia sp!, {d0-d15}
__no_vfp_frame_do3:
#endif
LDMIA sp!, {r4} @ pop new task's cpsr to spsr
MSR spsr_cxsf, r4
ldmfd sp!, {r0-r12,lr,pc}^ /* irq return */