common/bump.c

@@ -3,12 +3,15 @@
 #include "inc/msp432p401r.h"
 
 void BumpInit(void) {
+    // Port 4 pins 0, 2, 3, 5, 6, 7
+    // and enables internal resistors
     P4->SEL0 &= ~BUMP_PINS;
-    P4->SEL1 &= ~BUMP_PINS; // configure P4.0 P4.2 P4.3 P4.5 P4.6 P4.7 as gpio
+    P4->SEL1 &= ~BUMP_PINS; // 1) configure P4.0 P4.2 P4.3 P4.5 P4.6 P4.7 as gpio
-    P4->DIR  &= ~BUMP_PINS; // configure as input
+    P4->DIR  &= ~BUMP_PINS; // 2) configure as input
-    P4->REN  |=  BUMP_PINS; // enable pull resisors
+    P4->REN  |=  BUMP_PINS; // 3) enable pull resisors
 }
 
 uint8_t BumpRead(void) {
+    // write this as part of Lab 2
     return P4->IN;
 }

common/rtos.c

@@ -1,191 +0,0 @@
-#include <stdlib.h>
-
-#include "rtos.h"
-
-#include "clock.h"
-#include "cpu.h"
-#include "timer_a1.h"
-
-#include "inc/msp432p401r.h"
-
-#define THREADS 2
-#define PERIODIC_THREADS 2
-#define STACKSIZE 100
-
-typedef struct Tcb {
-    int32_t*    sp;        // stack pointer
-    struct Tcb* next;      // linked-list
-    int32_t*    blocked;   // shows on which semaphore it is blocked
-    int32_t     sleep;
-} Tcb_t;
-
-PeriodicEvent_t periodic_event_threads[PERIODIC_THREADS];
-
-Tcb_t   tcbs[THREADS];
-Tcb_t*  run_pt;
-int32_t stacks[THREADS][STACKSIZE];
-
-void RunPeriodicEvents(void);
-
-void __attribute__((naked)) SysTick_Handler(void) {
-    __asm volatile (    
-        "CPSID   I              \n" // disable interrupts
-        "PUSH    {R4-R11}       \n" // save  R4-R11
-        "LDR     R0, =run_pt    \n" // R0 = pointer to run_pt
-
-        "LDR     R1, [R0]       \n" // R1 = run_pt
-        "STR     SP, [R1]       \n" // save current SP
-
-        "PUSH    {R0, LR}       \n" // save R0, LR
-        "BL      Scheduler      \n" // call scheduler
-        "POP     {R0, LR}       \n" // restore R0, LR
-
-        "LDR     R1, [R0]       \n" // R1 = run_pt
-        "LDR     SP, [R1]       \n" // restore new SP
-
-        "POP     {R4-R11}       \n" // restore R4-R11
-        "CPSIE   I              \n" // enable interrupts
-        "BX      LR             \n" // exit exception
-        ".align 4               \n"
-    );
-}
-
-void __attribute__((naked))
-StartOS(void) {
-    __asm volatile (
-        "LDR     R0, =run_pt        \n" // address of run_pt
-        "LDR     R1, [R0]           \n" // R1 = run_pt
-        "LDR     SP, [R1]           \n" // SP = run_pt->sp
-
-        "POP     {R4-R11}           \n" // restore R4-R11
-        "POP     {R0-R3}            \n" // restore R0-R3
-        "POP     {R12}              \n" // restore R12
-        "ADD     SP, SP, #4         \n" // skip LR
-        "POP     {LR}               \n" // load thread start address
-        "ADD     SP, SP, #4         \n" // skip PSR
-        
-        "CPSIE   I                  \n" // enable interrupts
-        "BX      LR                 \n" // start thread
-        ".align 4                   \n"
-    );
-}
-
-
-void SetInitialStack(int i) {
-    tcbs[i].sp = &stacks[i][STACKSIZE-16];
-    stacks[i][STACKSIZE-1] = 0x01000000; // xPSR thumb bit
-
-    stacks[i][STACKSIZE-16] = 16;   // R4
-    stacks[i][STACKSIZE-15] = 15;   // R5
-    stacks[i][STACKSIZE-14] = 14;   // R6
-    stacks[i][STACKSIZE-13] = 13;   // R7
-    stacks[i][STACKSIZE-12] = 12;   // R8
-    stacks[i][STACKSIZE-11] = 11;   // R9
-    stacks[i][STACKSIZE-10] = 10;   // R10
-    stacks[i][STACKSIZE-9]  = 9;    // R11
-    stacks[i][STACKSIZE-8]  = 8;    // R0
-    stacks[i][STACKSIZE-7]  = 7;    // R1
-    stacks[i][STACKSIZE-6]  = 6;    // R2
-    stacks[i][STACKSIZE-5]  = 5;    // R3
-    stacks[i][STACKSIZE-4]  = 4;    // R12
-    stacks[i][STACKSIZE-3]  = 0;    // LR (0 causes fault if thread returns)
-
-}
-
-// Initialize operating system, disable interrupts
-// Initialize OS controlled I/O: systick, bus clock as fast as possible
-void RoundRobinInit(void) {
-    CPU_cpsid();
-    ClockInit48MHz();
-    // Write TimerA1Init here 1000 Hz
-}
-
-void AddThreads(void (**threads)(void)) {
-    uint32_t i = 0;
-    for (; i < THREADS; ++i) {
-        SetInitialStack(i);
-        stacks[i][STACKSIZE-2] = (int32_t)threads[i];
-        tcbs[i].next = &tcbs[ (i+1) % THREADS ];
-        tcbs[i].blocked = 0;
-        tcbs[i].sleep = 0;
-        // tcbs[i].priority = p0;
-    }
-    run_pt = &tcbs[0];
-}
-
-void AddPeriodicEventThreads(PeriodicEvent_t *periodic_events) {
-    uint32_t i = 0;
-    for (;i < PERIODIC_THREADS; ++i) {
-        periodic_event_threads[i] = periodic_events[i];
-    }
-}
-
-void RoundRobinLaunch(uint32_t time_slice_cycles) {
-    SysTick->CTRL = 0;                      // 1) disable SysTick during setup
-    SysTick->LOAD = time_slice_cycles - 1;  // 2) reload value sets period
-    SysTick->VAL = 0;                       // 3) any write to current clears it
-    SCB->SHP[11] = 7 << 5;                  // set priority into top 3 bits of 8-bit register
-    SysTick->CTRL = 0x00000007;             // 4) enable SysTick with core clock and interrupts
-
-    TimerA1Init(RunPeriodicEvents, 5000);   // 100Hz
-    StartOS();                              // start on the first task
-}
-
-void RunPeriodicEvents(void) {
-    int32_t i;
-    for (i = 0; i < THREADS; ++i) {
-        if (tcbs[i].sleep) {
-            --(tcbs[i].sleep);
-        }
-    }
-    for (i = 0; i < PERIODIC_THREADS; ++i) {
-        periodic_event_threads[i].event();
-    }
-}
-
-void Scheduler(void) {
-    Tcb_t* t = run_pt->next;
-    while (t->blocked || t->sleep) {
-        t = t->next;
-    }
-    
-    run_pt = t;
-}
-
-void Suspend(void) {
-    SysTick->VAL = 0; // clear
-    SCB->ICSR |= SCB_ICSR_PENDSTSET_Msk;   // trigger
-}
-
-void Sleep(int32_t time) {
-    run_pt->sleep = time;
-    Suspend();
-}
-
-// Decrement semaphore
-void Wait(int32_t *sema_pt) {
-    CPU_cpsid();
-    --(*sema_pt);
-    if((*sema_pt) < 0) {
-        run_pt->blocked = sema_pt; // reason it is blocked
-        
-        CPU_cpsie();
-        Suspend();
-    }
-    CPU_cpsie();
-}
-
-// Increment semaphore
-void Signal(int32_t *sema_pt) {
-    Tcb_t *pt;
-    CPU_cpsid();
-    ++(*sema_pt);
-    if ((*sema_pt) <= 0) {
-        pt = run_pt->next;
-        while(pt->blocked != sema_pt) {
-            pt = pt->next;
-        }
-        pt->blocked = 0;
-    }
-    CPU_cpsie();
-}

common/rtos.h

@@ -1,19 +0,0 @@
-#ifndef RTOS_H
-#define RTOS_H
-
-#include <stdint.h>
-
-typedef struct PeriodicEvent {
-	void (*event)(void);
-	uint32_t period_ms;
-} PeriodicEvent_t;
-
-void RoundRobinInit(void);
-void AddThreads(void (**threads)(void));
-void AddPeriodicEventThreads(PeriodicEvent_t *periodic_events);
-void RoundRobinLaunch(uint32_t time_slice_cycles);
-void Sleep(int32_t time);
-void Wait(int32_t *sema_pt);
-void Signal(int32_t *sema_pt);
-
-#endif /* RTOS_H */

project/Makefile

@@ -1,77 +0,0 @@
-CC = arm-none-eabi-gcc
-
-# The location of the C compiler
-# ARMGCC_ROOT is used by some makefiles that need to know where the compiler
-# is installed.
-ARMGCC_BIN := ${shell which ${CC}}
-ifeq (${shell test -h ${ARMGCC_BIN} && echo "true" || echo "false"}, true)
-    ARMGCC_ROOT := ${shell dirname ${shell readlink ${ARMGCC_BIN}}}/..
-else
-    ARMGCC_ROOT := ${shell dirname ${ARMGCC_BIN}}/..
-endif
-
-# Search for source files that are not in this directory
-VPATH = ../common/
-
-OBJECTS = main.o rtos.o timer_a1.o bump.o reflectance.o delay.o motor.o pwm.o cpu.o clock.o system.o startup.o syscalls.o
-
-NAME = lab
-
-CFLAGS = -I.. -I../inc -I../common \
-    -D__MSP432P401R__ \
-    -DDeviceFamily_MSP432P401x \
-    -mcpu=cortex-m4 \
-    -march=armv7e-m \
-    -mthumb \
-    -std=c99 \
-    -mfloat-abi=hard \
-    -mfpu=fpv4-sp-d16 \
-    -ffunction-sections \
-    -fdata-sections \
-    -gstrict-dwarf \
-    -Wall \
-    -I$(ARMGCC_ROOT)/arm-none-eabi/include/newlib-nano \
-    -I$(ARMGCC_ROOT)/arm-none-eabi/include
-
-LFLAGS = -Wl,-T,../config.lds \
-    -Wl,-Map,$(NAME).map \
-    -march=armv7e-m \
-    -mthumb \
-    -mfloat-abi=hard \
-    -mfpu=fpv4-sp-d16 \
-    -static \
-    -Wl,--gc-sections \
-	-lgcc \
-    -lc \
-    -lm \
-    -lnosys \
-    --specs=nano.specs
-
-all: $(NAME).out
-	@echo "SUCCESS: Compilation completed successfully."
-
-%.o: %.c
-	@$(CC) $(CFLAGS) -g $< -c -o $@
-
-cpu.o: ../common/cpu.c
-	@$(CC) $(CFLAGS) $< -c -o $@
-
-clock.o: ../common/clock.c
-	@$(CC) $(CFLAGS) $< -c -o $@
-
-system.o: ../system.c
-	@$(CC) $(CFLAGS) $< -c -o $@
-
-startup.o: ../startup.c
-	@$(CC) $(CFLAGS) $< -c -o $@
-
-syscalls.o: ../syscalls.c
-	@$(CC) $(CFLAGS) $< -c -o $@
-
-$(NAME).out: $(OBJECTS)
-	@$(CC) $(OBJECTS) $(LFLAGS) -o $(NAME).out
-
-clean: # Redirecting both the stderr and stdout to /dev/null 
-	@rm -f $(OBJECTS) > /dev/null 2>&1
-	@rm -f $(NAME).out > /dev/null 2>&1
-	@rm -f $(NAME).map > /dev/null 2>&1

project/main.c

@@ -1,136 +0,0 @@
-#include <stdint.h>
-#include <stdbool.h>
-#include <stdlib.h>
-
-#include "../common/rtos.h"
-#include "../common/pwm.h"
-#include "../common/bump.h"
-#include "../common/reflectance.h"
-#include "../common/motor.h"
-#include "../common/delay.h"
-
-#include "inc/msp432p401r.h"
-
-// bit-banded addresses, positive logic
-#define SW2IN ((*((volatile uint8_t *)(0x42098010)))^1)
-#define SW1IN ((*((volatile uint8_t *)(0x42098004)))^1)
-
-// bit-banded address
-#define REDLED (*((volatile uint8_t *)(0x42098040)))
-
-// bit-banded addresses
-#define BLUEOUT  (*((volatile uint8_t *)(0x42098068)))
-#define GREENOUT (*((volatile uint8_t *)(0x42098064)))
-#define REDOUT   (*((volatile uint8_t *)(0x42098060)))
-
-#define START_REFLECTANCE 9
-
-int32_t bump_pressed; // semaphore
-
-uint8_t bump_data, reflectance_data;
-
-void WaitTouchRelease(void) {
-    while(!(SW1IN || SW2IN));  // wait for touch
-    while(  SW1IN || SW2IN );  // wait for release
-}
-
-void SwitchInit(void) {
-    P1->SEL0 &= ~0x12;
-    P1->SEL1 &= ~0x12;    // 1) configure P1.4 and P1.1 as GPIO
-    P1->DIR &= ~0x12;     // 2) make P1.4 and P1.1 in
-    P1->REN |= 0x12;      // 3) enable pull resistors on P1.4 and P1.1
-    P1->OUT |= 0x12;      //    P1.4 and P1.1 are pull-up
-}
-
-void RedLEDInit(void) {
-    P1->SEL0 &= ~0x01;
-    P1->SEL1 &= ~0x01;   // 1) configure P1.0 as GPIO
-    P1->DIR |= 0x01;     // 2) make P1.0 out
-}
-
-void ColorLEDInit(void) {
-    P2->SEL0 &= ~0x07;
-    P2->SEL1 &= ~0x07;    // 1) configure P2.2-P2.0 as GPIO
-    P2->DIR |= 0x07;      // 2) make P2.2-P2.0 out
-    P2->DS |= 0x07;       // 3) activate increased drive strength
-    P2->OUT &= ~0x07;     //    all LEDs off
-}
-
-void led_task(void) {
-    while (true) {
-        if (SW1IN && SW2IN) {
-            GREENOUT = 1;
-        } else {
-            GREENOUT = 0;
-        }
-        if (SW1IN || SW2IN) {
-            REDLED = 1;
-        } else {
-            REDLED = 0;
-        }
-        if (SW1IN) {
-            BLUEOUT = 1;
-        } else {
-            BLUEOUT = 0;
-        }
-        if (SW2IN) {
-            REDOUT = 1;
-        } else {
-            REDOUT = 0;
-        }
-    }
-}
-
-void drive_task(void) {
-    while (1) {
-        bump_pressed = 0;
-        MotorForward(1000, 1000);
-        Wait(&bump_pressed);
-        MotorBackward(800, 800);
-        Sleep(1000);
-        MotorLeft(800, 800);
-        Sleep(2000);
-    }
-}
-
-uint32_t refl_tick_count = 0;
-void reflectance_task(void) {
-    ++refl_tick_count;
-
-    if (1 == (refl_tick_count % 10)) {
-        ReflectanceStart();
-    }
-
-    if (2 == (refl_tick_count % 10)) {
-        reflectance_data  = ReflectanceEnd();
-    }
-}
-
-void bump_task(void) {
-    bump_data = BumpRead();
-    if ((~bump_data & BUMP_PINS)) {
-        Signal(&bump_pressed);
-    }
-}
-
-int main(void) {
-    BumpInit();
-    ReflectanceInit();
-    PWMInitMotor(3751);
-    MotorInit();
-
-    RedLEDInit();
-    ColorLEDInit();
-    SwitchInit();
-    RoundRobinInit();
-    AddThreads((void (*[])(void)){
-        led_task,
-        drive_task
-    });
-    AddPeriodicEventThreads((PeriodicEvent_t []) {
-        {reflectance_task, 1}, 
-        {bump_task, 100}
-    });
-    RoundRobinLaunch(48000); // 1ms
-    return 0;   // never executes
-}