1*10465441SEvalZero/* 2*10465441SEvalZero * Copyright (c) 2006-2018, RT-Thread Development Team 3*10465441SEvalZero * 4*10465441SEvalZero * SPDX-License-Identifier: Apache-2.0 5*10465441SEvalZero * 6*10465441SEvalZero * Change Logs: 7*10465441SEvalZero * Date Author Notes 8*10465441SEvalZero */ 9*10465441SEvalZero.global rt_hw_interrupt_disable 10*10465441SEvalZero.global rt_hw_interrupt_enable 11*10465441SEvalZero.global rt_hw_context_switch 12*10465441SEvalZero.global rt_hw_context_switch_to 13*10465441SEvalZero.global rt_hw_context_switch_interrupt 14*10465441SEvalZero 15*10465441SEvalZero.equ NOINT, 0xc0 16*10465441SEvalZero 17*10465441SEvalZero/* 18*10465441SEvalZero * rt_base_t rt_hw_interrupt_disable(); 19*10465441SEvalZero 关闭中断，关闭前返回CPSR寄存器值 20*10465441SEvalZero */ 21*10465441SEvalZerort_hw_interrupt_disable: 22*10465441SEvalZero //EXPORT rt_hw_interrupt_disable 23*10465441SEvalZero MRS r0, cpsr 24*10465441SEvalZero ORR r1, r0, #NOINT 25*10465441SEvalZero MSR cpsr_c, r1 26*10465441SEvalZero BX lr 27*10465441SEvalZero //ENDP 28*10465441SEvalZero 29*10465441SEvalZero/* 30*10465441SEvalZero * void rt_hw_interrupt_enable(rt_base_t level); 31*10465441SEvalZero 恢复中断状态 32*10465441SEvalZero */ 33*10465441SEvalZerort_hw_interrupt_enable: 34*10465441SEvalZero //EXPORT rt_hw_interrupt_enable 35*10465441SEvalZero MSR cpsr_c, r0 36*10465441SEvalZero BX lr 37*10465441SEvalZero //ENDP 38*10465441SEvalZero 39*10465441SEvalZero/* 40*10465441SEvalZero * void rt_hw_context_switch(rt_uint32 from, rt_uint32 to); 41*10465441SEvalZero * r0 --> from 42*10465441SEvalZero * r1 --> to 43*10465441SEvalZero 进行线程的上下文切换 44*10465441SEvalZero */ 45*10465441SEvalZerort_hw_context_switch: 46*10465441SEvalZero //EXPORT rt_hw_context_switch 47*10465441SEvalZero STMFD sp!, {lr} /* push pc (lr should be pushed in place of PC) */ 48*10465441SEvalZero /* 把LR寄存器压入栈（这个函数返回后的下一个执行处） */ 49*10465441SEvalZero STMFD sp!, {r0-r12, lr} /* push lr & register file */ 50*10465441SEvalZero /* 把R0 – R12以及LR压入栈 */ 51*10465441SEvalZero 52*10465441SEvalZero MRS r4, cpsr /* 读取CPSR寄存器到R4寄存器 */ 53*10465441SEvalZero STMFD sp!, {r4} /* push cpsr */ 54*10465441SEvalZero /* 把R4寄存器压栈（即上一指令取出的CPSR寄存器） */ 55*10465441SEvalZero MRS r4, spsr /* 读取SPSR寄存器到R4寄存器 */ 56*10465441SEvalZero STMFD sp!, {r4} /* push spsr */ 57*10465441SEvalZero /* 把R4寄存器压栈（即SPSR寄存器） */ 58*10465441SEvalZero 59*10465441SEvalZero STR sp, [r0] /* store sp in preempted tasks TCB */ 60*10465441SEvalZero /* 把栈指针更新到TCB的sp，是由R0传入此函数 */ 61*10465441SEvalZero /* 到这里换出线程的上下文都保存在栈中 */ 62*10465441SEvalZero LDR sp, [r1] /* get new task stack pointer */ 63*10465441SEvalZero /* 载入切换到线程的TCB的sp */ 64*10465441SEvalZero /* 从切换到线程的栈中恢复上下文，次序和保存的时候刚好相反 */ 65*10465441SEvalZero 66*10465441SEvalZero LDMFD sp!, {r4} /* pop new task spsr */ 67*10465441SEvalZero /* 出栈到R4寄存器（保存了SPSR寄存器） */ 68*10465441SEvalZero MSR spsr_cxsf, r4 /* 恢复SPSR寄存器 */ 69*10465441SEvalZero LDMFD sp!, {r4} /* pop new task cpsr */ 70*10465441SEvalZero /* 出栈到R4寄存器（保存了CPSR寄存器） */ 71*10465441SEvalZero MSR cpsr_cxsf, r4 /* 恢复CPSR寄存器 */ 72*10465441SEvalZero 73*10465441SEvalZero LDMFD sp!, {r0-r12, lr, pc} /* pop new task r0-r12, lr & pc */ 74*10465441SEvalZero /* 对R0 – R12及LR、PC进行恢复 */ 75*10465441SEvalZero //ENDP 76*10465441SEvalZero 77*10465441SEvalZerort_hw_context_switch_to: 78*10465441SEvalZero //EXPORT rt_hw_context_switch_to 79*10465441SEvalZero LDR sp, [r0] /* get new task stack pointer */ 80*10465441SEvalZero /* 获得切换到线程的SP指针 */ 81*10465441SEvalZero 82*10465441SEvalZero LDMFD sp!, {r4} /* pop new task spsr */ 83*10465441SEvalZero /* 出栈R4寄存器（保存了SPSR寄存器值） */ 84*10465441SEvalZero MSR spsr_cxsf, r4 /* 恢复SPSR寄存器 */ 85*10465441SEvalZero LDMFD sp!, {r4} /* pop new task cpsr */ 86*10465441SEvalZero /* 出栈R4寄存器（保存了CPSR寄存器值） */ 87*10465441SEvalZero MSR cpsr_cxsf, r4 /* 恢复CPSR寄存器 */ 88*10465441SEvalZero 89*10465441SEvalZero LDMFD sp!, {r0-r12, lr, pc} /* pop new task r0-r12, lr & pc */ 90*10465441SEvalZero /* 恢复R0 – R12，LR及PC寄存器 */ 91*10465441SEvalZero //ENDP 92*10465441SEvalZero 93*10465441SEvalZerort_hw_context_switch_interrupt: 94*10465441SEvalZero //EXPORT rt_hw_context_switch_interrupt 95*10465441SEvalZero LDR r2, =rt_thread_switch_interrupt_flag 96*10465441SEvalZero LDR r3, [r2] /* 载入中断中切换标致地址 */ 97*10465441SEvalZero CMP r3, #1 /* 等于 1 ？*/ 98*10465441SEvalZero BEQ _reswitch /* 如果等于1，跳转到_reswitch*/ 99*10465441SEvalZero MOV r3, #1 /* set rt_thread_switch_interrupt_flag to 1*/ 100*10465441SEvalZero /* 设置中断中切换标志位1 */ 101*10465441SEvalZero STR r3, [r2] /* */ 102*10465441SEvalZero LDR r2, =rt_interrupt_from_thread /* set rt_interrupt_from_thread*/ 103*10465441SEvalZero STR r0, [r2] /* 保存切换出线程栈指针*/ 104*10465441SEvalZero_reswitch: 105*10465441SEvalZero LDR r2, =rt_interrupt_to_thread /* set rt_interrupt_to_thread*/ 106*10465441SEvalZero STR r1, [r2] /* 保存切换到线程栈指针*/ 107*10465441SEvalZero BX lr 108*10465441SEvalZero //ENDP 109*10465441SEvalZero 110*10465441SEvalZero //END