Министерство образования и науки Российской Федерации
Федеральное государственное бюджетное образовательное учреждение
высшего профессионального образования
«САРАТОВСКИЙ НАЦИОНАЛЬНЫЙ ИССЛЕДОВАТЕЛЬСКИЙ ГОСУДАРСТВЕННЫЙ УНИВЕРСИТЕТ ИМЕНИ Н.Г.ЧЕРНЫШЕВСКОГО»







Лабораторная работа №3
по дисциплине
«Системы реального времени»







Студентов 4 курса
факультета КНиИТ
441 группы
Луг Юрия Александровича
Батыр Егора Валерьевича
Исайкина Виктора Викторовича










Саратов 2017
Assembler code:


Stack_Size      EQU     0x00000400

                AREA    STACK, NOINIT, READWRITE, ALIGN=3
Stack_Mem       SPACE   Stack_Size
__initial_sp


                PRESERVE8
                THUMB


; Vector Table Mapped to Address 0 at Reset
                AREA    RESET, DATA, READONLY
                EXPORT  __Vectors
                EXPORT  __Vectors_End
                EXPORT  __Vectors_Size

__Vectors       DCD     __initial_sp               ; Top of Stack
                DCD     Reset_Handler              ; Reset Handler
				SPACE 168
				DCD TIM2_Handler
__Vectors_End

__Vectors_Size  EQU  __Vectors_End - __Vectors

                AREA    |.text|, CODE, READONLY

SaveContext 	PROC
					EXPORT SaveContext
					; POINER TO CONTEXT IN R0 (argument)

					LDR r1, [sp, #12] ; r0 from stack -> r1
					STR r1, [r0, #0x00] ; r1 (temp) -> context.gpr;

					LDR r1, [sp, #12+4] ; r1 from stack -> r1
					STR r1, [r0, #0x04] ; r1 (temp) -> context.gpr;

					LDR r1, [sp, #12+8] ; r2 from stack -> r1
					STR r1, [r0, #0x08]  ; r1 (temp) -> context.gpr;

					LDR r1, [sp, #12+12] ; r3 from stack -> r1
					STR r1, [r0, #0x0C] ; r1 (temp) -> context.gpr;

					STR r4, [r0, #0x10] ; r4 (temp) -> context.gpr;
					STR r5, [r0, #0x14] ; r5 (temp) -> context.gpr;
					STR r6, [r0, #0x18] ; r6 (temp) -> context.gpr;
					STR r7, [r0, #0x1C] ; r7 (temp) -> context.gpr;
					STR r8, [r0, #0x20] ; r8 (temp) -> context.gpr;
					STR r9, [r0, #0x24] ; r9 (temp) -> context.gpr;
					STR r10, [r0, #0x28] ; r10 (temp) -> context.gpr;
					STR r11, [r0, #0x2C] ; r11 (temp) -> context.gpr;

					LDR r1, [sp, #12+16] ; r12 from stack -> r1
					STR r1, [r0, #0x30] ; r1 (temp) -> context.gpr;

					LDR r1, [sp, #12+24] ; PC (ReturnAdderss()) from stack -> r1
					STR r1, [r0, #0x34] ; r1 (temp) -> context.pc;

					LDR r1, [sp, #12+20] ; LR from stack -> r1
					STR r1, [r0, #0x38] ; r1 (temp) -> context.lr;

					MOV r1, sp	; sp -> r1 (temp)
					STR r1, [r0, #0x3c] ; r1 (temp) -> context.sp;

					LDR r1, [sp, #12+28] ; xPSR from stack -> r1
					STR r1, [r0, #0x40] ; r1 (temp) -> context.psw;

					BX LR
				ENDP

RestoreContext 	PROC
					EXPORT RestoreContext
					LDR R2,[sp, #0] ; pop system values
					LDR R3,[sp, #4]
					LDR R4,[sp, #8]

					LDR R1,[r0, #0x3c] ; sp from struct -> r1
					mov SP,R1			; r1 -> sp

					STR R2,[sp, #0] ; return system values to stack
					STR R3,[sp, #4]
					STR R4,[sp, #8]


					LDR r1, [r0, #0x00] ; r0 from context.gpr -> r1
					STR r1, [sp, #12] ; r1 (temp) -> stack;

					LDR r1, [r0, #0x04] ; r1 from  context.gpr-> r1
					STR r1, [sp, #12+4] ; r1 (temp) ->stack

					LDR r1, [r0, #0x08] ; r2 from context.gpr -> r1
					STR r1, [sp, #12+8]   ; r1 (temp) -> stack

					LDR r1, [r0, #0x0C] ; r3 from context.gpr -> r1
					STR r1, [sp, #12+12] ; r1 (temp) -> stack

					LDR r1 ,[r0, #0x10] ; r4 from context.gpr ->r1 (temp)
					mov r4,r1;		; r1(temp) -> r4

					LDR r1 ,[r0, #0x14] ; r5 from context.gpr ->r1 (temp)
					mov r5,r1; 		; r1(temp) -> r5

					LDR r1 ,[r0, #0x18] ; r6 from context.gpr ->r1 (temp)
					mov r6,r1; 		; r1(temp) -> r6

					LDR r1 ,[r0, #0x1C] ; r7 from context.gpr ->r1 (temp)
					mov r7,r1; 		; r1(temp) -> r7

					LDR r1 ,[r0, #0x20] ; r8 from context.gpr ->r1 (temp)
					mov r8,r1; 		; r1(temp) -> r8

					LDR r1 ,[r0, #0x24] ; r9 from context.gpr ->r1 (temp)
					mov r9,r1; 		; r1(temp) -> r9

					LDR r1 ,[r0, #0x28] ; r10 from context.gpr ->r1 (temp)
					mov r10,r1; 		; r1(temp) -> r10

					LDR r1 ,[r0, #0x2C] ; r11 from context.gpr ->r1 (temp)
					mov r11,r1; 		; r1(temp) -> r11

					LDR r1, [r0, #0x30] ; r12 from context.gpr -> r1
					STR r1, [sp, #12+16] ; r1 (temp) -> stack

					LDR r1, [r0, #0x34] ; PC from context.pc -> r1
					STR r1, [sp, #12+24] ; r1 (temp) -> stack

					LDR r1, [r0, #0x38] ; LR from context.lr -> r1
					STR r1, [sp, #12+20] ; r1 (temp) -> stack

					LDR r1, [r0, #0x40] ; xPSR from context.psw -> r1
					STR r1,[sp, #12+28]  ; r1 (temp) -> stack

					BX LR
				ENDP

TIM2_Handler 	PROC
					IMPORT OSkernel

					MOV R0, LR
					PUSH {R0}

					BL OSkernel

					POP {R0}
					MOV LR, R0

					LDR R0, =0x40000000
					LDR R1, [R0, #0x10]
					LDR R2, =~0x00000001
					AND R1, R2
					STR R1, [R0, #0x10]

					;LDR R0, =0x48001000
					;LDR R1, [R0, #0x14]
					;LDR R2, =0x00000800
					;EOR R1,R2
					;STR R1,[R0,#0x14]

					ISB

					BX LR
				ENDP

; Reset handler
Reset_Handler    PROC

					EXPORT  Reset_Handler             [WEAK]

					IMPORT OSinit




					 ; init
					 ; SystemInit()

					 ; rcc start
					 ; mod led port
					 LDR R0, =0x40021000
					 LDR R1, [R0, #0x14]
					 LDR R2, =0x00200000
					 ORR R1,R2
					 STR R1,[R0,#0x14]

					 ; mod timer port
					 LDR R0, =0x40021000
					 LDR R1, [R0, #0x1C]
					 LDR R2, =0x00000001
					 ORR R1,R2
					 STR R1,[R0,#0x1C]

					 ; timer counter settings
					 ; cnt reg
					 LDR R0, =0x40000000
					 LDR R2, =0x00000000
					 STR R2, [R0, #0x24]

					 ; arr reg
					 LDR R0, =0x40000000
					 LDR R2, = 1000
					 STR R2, [R0, #0x2C]

					 ; psc reg
					 LDR R0, =0x40000000
					 LDR R2, = 0 ;400
					 STR R2, [R0, #0x28]

					 ; dier reg
					 LDR R0, =0x40000000
					 LDR R2, =0x00000001
					 STR R2, [R0, #0x0C]

					 ; nvic_iser
					 LDR R0, =0xE000E100
					 LDR R2, =0x10000000
					 STR R2, [R0, #0x00]

					 ; cr1 reg
					 LDR R0, =0x40000000
					 LDR R1, [R0, #0x00]
					 LDR R2, =0x00000001
					 ORR R1,R2
					 STR R1,[R0,#0x00]



					 ; moder on
					 LDR R0, =0x48001000
					 LDR R1, [R0, #0x00]
					 LDR R2, =0x40400000
					 ORR R1,R2
					 STR R1,[R0,#0x00]

					 					 ;include from main.c



					BL OSinit

					 IMPORT main
					 LDR R0,=main
					 BLX R0

loop_off_true
					 ; block
					 CPSID I

					 ; loop start conditions
					 LDR R11, =0x000F4240
					 LDR R12, =0x000F4240

					 ; odr on
					 LDR R1, [R0, #0x14]
					 LDR R2, =0x00008000

					 ; waiting loop start consitions
					 LDR R9,  =0x00051615

loop_wait_false
					 ; wait actions
					 SUB R9, #0x00000001
					 CMP R9, #0x00000000
					 BNE loop_wait_false

					 ;continue odr on
					 ORR R1,R2
					 STR R1,[R0,#0x14]

					 ; unblock
					 CPSIE I

loop_on_false
					 ; wait off loop
					 SUB R11, #0x00000001
					 CMP R11, #0x00000000
					 BEQ loop_on_true
					 BNE loop_on_false

loop_on_true
					 ; odr off
					 LDR R1, [R0, #0x14]
					 LDR R2, =~0x00008000
					 AND R1,R2
					 STR R1,[R0,#0x14]

loop_off_false		 ; wait off loop
					 SUB R12, #0x00000001
					 CMP R12, #0x00000000
					 BEQ loop_off_true
					 BNE loop_off_false
					 B .

                 ENDP


                 ALIGN


                 END

;************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE*****


Main.c:
#include "stm32f30x.h"

int wait(unsigned int ms);
volatile int period;

extern unsigned long GlobalTime;
#define MAXGLOBALTIME 0x10000000

#define MAXN 4

unsigned int store[MAXN];
unsigned int data = 0;
unsigned int isr = 0;
unsigned int isEmptyStore = 0;

int main() {
	//unsigned int data = 0;

	RCC->APB2ENR |= 0x00004000; // tacting running on
	USART1->BRR = 0x228; //0x8a; 		// velocity
	USART1->CR1 |= 0x0000000d;	// turn on

	RCC->AHBENR |= 0x00020000; // include clicking
	GPIOA->MODER |= 0x00280000; // alternative function for output
	GPIOA->AFR[1] = 0x00000770; // choise the function
}

void input() { // task 1
	main();

	while (1) {

		__disable_irq(); //interruption stop
		isr = USART1->ISR;

		if (isr & 0x00000008) {
			USART1->ICR |= 0x00000008;
		}

		if ((isr & 0x00000020) && !isEmptyStore) { // if exists something for accept - accept it
			data = USART1->RDR;
			isEmptyStore = 1;
		}

		__enable_irq();// interruption continue
	}
}

void output() { // task 2
	while (1) {

		__disable_irq(); //interruption stop

		isr = USART1->ISR;
		if ((isr & 0x00000080) && isEmptyStore) { // // if exists something for send - send it
			USART1->TDR = data;
			isEmptyStore = 0;
		}

		__enable_irq();// interruption continue
	}
}

void greatWork() { //task 3
	// init

	while (1) {
		//
	}
}

void *const Tasks[] __attribute__((at(0x08001000)))= { // our tasks
	input,
	output,
	greatWork,
	greatWork,
	0
};


EYOS.c (OS):
#include "stm32f30x.h"

unsigned char Stacks[8][0x200];

unsigned long GlobalTime;
#define MAXGLOBALTIME 0x10000000

struct {// struct of registers
    unsigned int GPR[13];
    void *PC;
    void *LR;
    void *SP;
    unsigned int PSW; // xPSR
} contexts[8];

extern void *Tasks[];
unsigned char tnum; // number of a task
unsigned char tcur; // current task
typedef void (*func)(void);

void SaveContext(void *conptr);
void RestoreContext(void *conptr);

void OSkernel() { //  task switch
	if (++GlobalTime >= MAXGLOBALTIME) {
		GlobalTime = 0;
	}

	SaveContext(&contexts[tcur]); // save all parameters of the program

	tcur = (tcur + 1) % (tnum+1);
	if(tcur == 0)
	{
		tcur = 1;
	}

	RestoreContext(&contexts[tcur]); // restore all parameters of the program
}

void OSinit() {
    int i;

    // context init
    i = 0;

    while (Tasks[i] != 0) {
        contexts[i + 1].PC = (void *)(((int) (Tasks[i])) | (1));
        contexts[i + 1].SP = &Stacks[i][0x200 - 4];
        contexts[i + 1].PSW = 0x01000000;
        i++;
    }

    tnum = i;
    tcur = 0;

	NVIC->ISER[0] |=0x00008000;

    for (;;) {
    }
}