rt-thread-official/bsp/qemu-vexpress-a9/cpu/context_gcc.S

174 lines
5.0 KiB
ArmAsm

/*
* File : context.S
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2013, RT-Thread Development Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Change Logs:
* Date Author Notes
* 2013-07-05 Bernard the first version
* 2018-11-22 Jesven in the smp version, using macro to
* define rt_hw_interrupt_enable and rt_hw_interrupt_disable
* rt_hw_context_switch_interrupt switches to the new thread directly
*/
#include "rtconfig.h"
.section .text, "ax"
#ifdef RT_USING_SMP
#define rt_hw_interrupt_disable rt_hw_local_irq_disable
#define rt_hw_interrupt_enable rt_hw_local_irq_enable
#endif
/*
* 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_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_SMP
mov r0, r1
bl rt_cpus_lock_status_restore
#endif /*RT_USING_SMP*/
ldmfd sp!, {r4} @ pop new task spsr
msr spsr_cxsf, r4
ldmfd sp!, {r0-r12, lr, pc}^ @ pop new task r0-r12, lr & pc
.section .bss.share.isr
_guest_switch_lvl:
.word 0
.section .text.isr, "ax"
/*
* void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
* r0 --> from
* r1 --> to
*/
.globl rt_hw_context_switch
rt_hw_context_switch:
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
str sp, [r0] @ store sp in preempted tasks TCB
ldr sp, [r1] @ get new task stack pointer
#ifdef RT_USING_SMP
mov r0, r2
bl rt_cpus_lock_status_restore
#endif /*RT_USING_SMP*/
ldmfd sp!, {r4} @ pop new task cpsr to spsr
msr spsr_cxsf, r4
ldmfd sp!, {r0-r12, lr, pc}^ @ pop new task r0-r12, lr & pc, copy spsr to cpsr
/*
* void rt_hw_context_switch_interrupt(rt_uint32 from, rt_uint32 to);
*/
.equ Mode_USR, 0x10
.equ Mode_FIQ, 0x11
.equ Mode_IRQ, 0x12
.equ Mode_SVC, 0x13
.equ Mode_ABT, 0x17
.equ Mode_UND, 0x1B
.equ Mode_SYS, 0x1F
.equ I_Bit, 0x80 @ when I bit is set, IRQ is disabled
.equ F_Bit, 0x40 @ when F bit is set, FIQ is disabled
.globl rt_thread_switch_interrupt_flag
.globl rt_interrupt_from_thread
.globl rt_interrupt_to_thread
.globl rt_hw_context_switch_interrupt
rt_hw_context_switch_interrupt:
#ifdef RT_USING_SMP
/* r0 :irq_mod context
* r1 :addr of from_thread's sp
* r2 :addr of to_thread's sp
* r3 :to_thread's tcb
*/
@ r0 point to {r0-r3} in stack
push {r1 - r3}
mov r1, r0
add r0, r0, #4*4
ldmfd r0!, {r4-r12,lr}@ reload saved registers
mrs r3, spsr @ get cpsr of interrupt thread
sub r2, lr, #4 @ save old task's pc to r2
msr cpsr_c, #I_Bit|F_Bit|Mode_SVC
stmfd sp!, {r2} @ push old task's pc
stmfd sp!, {r4-r12,lr}@ push old task's lr,r12-r4
ldmfd r0, {r4-r7} @ restore r0-r3 of the interrupt thread
stmfd sp!, {r4-r7} @ push old task's r0-r3
stmfd sp!, {r3} @ push old task's cpsr
msr cpsr_c, #I_Bit|F_Bit|Mode_IRQ
pop {r1 - r3}
mov sp, r0
msr cpsr_c, #I_Bit|F_Bit|Mode_SVC
str sp, [r1]
ldr sp, [r2]
mov r0, r3
bl rt_cpus_lock_status_restore
ldmfd sp!, {r4} @ pop new task's cpsr to spsr
msr spsr_cxsf, r4
ldmfd sp!, {r0-r12,lr,pc}^ @ pop new task's r0-r12,lr & pc, copy spsr to cpsr
#else /*RT_USING_SMP*/
ldr r2, =rt_thread_switch_interrupt_flag
ldr r3, [r2]
cmp r3, #1
beq _reswitch
ldr ip, =rt_interrupt_from_thread @ set rt_interrupt_from_thread
mov r3, #1 @ set rt_thread_switch_interrupt_flag to 1
str r0, [ip]
str r3, [r2]
_reswitch:
ldr r2, =rt_interrupt_to_thread @ set rt_interrupt_to_thread
str r1, [r2]
bx lr
#endif /*RT_USING_SMP*/