tonyp12 ( Tony Philipsson ) posted code for a small preemptive multi tasking kernel on 43oh.com
http://forum.43oh.com/topic/9450-tiny-msp430-preemptive-multitasking-system/?p=71458
That code was written for IAR. As I'm not in the deep pockets IAR camp, I ported it to msp430-gcc and msp430-elf-gcc.
License for tony's code:
"Code is free for non-commercial use, for commerical use a negotiated donation amount. Though commercial use will be after I added more features."
-rick
| /* | |
| * common.h | |
| */ | |
| #ifndef COMMON_H_ | |
| #define COMMON_H_ | |
| #include <msp430.h> | |
| #include "sys.h" | |
| #ifndef FIXED_REG | |
| #if __GNUC__ == 4 && __GNUC_MINOR__ == 6 | |
| #define FIXED_REG "r4" | |
| #else | |
| #define FIXED_REG "R4" | |
| #endif | |
| #endif | |
| #define __task __attribute__((naked, used, noreturn)) | |
| __task extern void task1(void); | |
| __task extern void task2(void); | |
| __task extern void task3(void); | |
| __task extern void task4(void); | |
| typedef void (*taskptr)(void); | |
| #endif | |
| -- license.txt -- | |
| This file really needs to be fleshed out. When I asked what the license for the code | |
| was I got this answer from Tony: | |
| "Code is free for non-commercial use, for commerical use a negotiated donation amount. | |
| Though commercial use will be after I added more features." | |
| //=========================(C) Tony Philipsson 2016 ======================= | |
| // | |
| // tiny msp430 preemptive multitasking system | |
| // | |
| // http://forum.43oh.com/topic/9450-tiny-msp430-preemptive-multitasking-system/?p=71458 | |
| // | |
| // Changes: | |
| // 2016/03/18 Rick Kimball port to msp430-gcc MSP430G2553 and MSP430FR5969 | |
| // | |
| #include "common.h" | |
| #define SAVED_STACK_WORDS 11 | |
| #define MIN_STACK_WORDS (SAVED_STACK_WORDS+1+1) | |
| #define tasks (sizeof(taskpnt)/sizeof(taskpnt[0])) | |
| static taskptr const taskpnt[] = { | |
| task1, task2, task3 | |
| }; | |
| static const unsigned stacksize[tasks] = { | |
| MIN_STACK_WORDS+4+4+2+10, MIN_STACK_WORDS+4+4+2+10, MIN_STACK_WORDS+4+4+2+10 | |
| }; | |
| //========================================================================= | |
| static unsigned taskstackpnt[tasks]; | |
| volatile systick_t systick; | |
| register unsigned *taskrun asm(FIXED_REG); | |
| int main( void ) | |
| { | |
| WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer | |
| BCSCTL1 = CALBC1_8MHZ; // Set DCO to factory calibrated 8MHz | |
| DCOCTL = CALDCO_8MHZ; | |
| DCOCTL += 13; // overclock 103% or 8.22MHz | |
| #define MEASURE_ISR_OVHEAD 0 | |
| #if MEASURE_ISR_OVHEAD | |
| P1DIR |= BIT4; P1SEL |= BIT4; // measure DCO | |
| P2DIR |= BIT0; P2OUT &= ~BIT0; // toggles pin during wdt isr | |
| #endif | |
| taskrun = taskstackpnt; | |
| register unsigned * multistack; | |
| register unsigned i; | |
| multistack = (unsigned *)__get_SP_register(); | |
| i=0; | |
| while( i < tasks-1) { | |
| multistack -= stacksize[i]; // adjust stack to accomodate n stack words | |
| *(multistack) = (unsigned)taskpnt[++i]; // prefill in PC | |
| *(multistack-1) = GIE; // prefill in SR | |
| taskstackpnt[i] = (unsigned) | |
| (multistack-((MIN_STACK_WORDS)-1)); // point at dummy stack words | |
| } | |
| WDTCTL = WDT_MDLY_8; // 1ms tick using MCLK | |
| IE1 |= WDTIE; | |
| __enable_interrupt(); | |
| asm volatile (" br 0(%0)\n":: "r" (taskpnt)); // indirect jmp to first task | |
| } | |
| //============= TASK SWITCHER ISR ============= | |
| __attribute__((interrupt(WDT_VECTOR), naked, used)) | |
| void taskswitcher(void); | |
| void taskswitcher(void) | |
| { | |
| #if MEASURE_ISR_OVHEAD | |
| asm("xor.b #1, %0" :: "m" (P2OUT)); // toggle pin to measure overhead | |
| #endif | |
| __asm__ volatile ( | |
| "push R15\n push R14\n push R13\n push R12\n" | |
| "push R11\n push R10\n push R9\n push R8\n" | |
| "push R7\n push R6\n" | |
| "push R5\n" | |
| ); | |
| #if 1 | |
| __asm__ volatile (" inc %A0\n" :: "m" (systick)); | |
| __asm__ volatile (" adc %B0\n" :: "m" (systick)); | |
| #else | |
| ++systick; | |
| #endif | |
| __asm__ volatile ( | |
| " mov r1, 0(%2)\n" | |
| " incd %2\n" | |
| " cmp %0,%2\n" | |
| " jnz 1f\n" | |
| " mov %1, %2\n" | |
| "1:\n" | |
| " mov 0(%2), r1\n" | |
| ::"i" (taskstackpnt+tasks) | |
| ,"i" (taskstackpnt) | |
| ,"r" (taskrun) | |
| ); | |
| __asm__ volatile ( | |
| "pop R5\n" | |
| "pop R6\n pop R7\n" | |
| "pop R8\n pop R9\n pop R10\n pop R11\n" | |
| "pop R12\n pop R13\n pop R14\n pop R15" | |
| ); | |
| #if MEASURE_ISR_OVHEAD | |
| asm("xor.b #1, %0" :: "m" (P2OUT)); // toggle pin to measure overhead | |
| #endif | |
| asm("reti"); // we need to add because of naked attribute | |
| } |
| //========================= Copyright (c) 2016 Tony Philipsson ======================= | |
| // main.c - tiny msp430 preemptive multitasking system | |
| // | |
| // See: | |
| // http://forum.43oh.com/topic/9450-tiny-msp430-preemptive-multitasking-system/?p=71458 | |
| // | |
| // Changes: | |
| // 2016/03/18 Rick Kimball port to msp430-gcc MSP430G2553 and MSP430FR5969 | |
| // 2016/03/20 Rick Kimball version specific for FR5969 using FRAM as stack | |
| // | |
| #include <stdint.h> | |
| #include "common.h" | |
| #define SAVED_STACK_WORDS 11 | |
| #define MIN_STACK_WORDS (SAVED_STACK_WORDS+1+1) | |
| #define tasks (sizeof(taskpnt)/sizeof(taskpnt[0])) | |
| static taskptr const taskpnt[] = { | |
| task1, task2, task3, task4 | |
| }; | |
| #define STACK_WORD_SIZE (1024+128+256+64) | |
| static const unsigned stacksize[tasks] = { | |
| 1024, 128, 256, 64 | |
| }; | |
| static unsigned taskstackpnt[tasks]; | |
| unsigned *alt_stack_space; | |
| volatile systick_t systick; | |
| register unsigned *taskrun asm(FIXED_REG); | |
| //========================================================================= | |
| void main( void ) | |
| { | |
| WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer | |
| PM5CTL0 &= ~LOCKLPM5; // Unlock Pin Registers | |
| CSCTL0_H = CSKEY >> 8; // Unlock CS registers | |
| CSCTL1 = DCOFSEL_6; // Set DCO to 8MHz | |
| CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK; // SMCLK/MCLK DCO and VLO | |
| CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1; // Set all dividers to 1 | |
| CSCTL0_H = 0; // Lock CS registers | |
| P3DIR |= BIT0; P3OUT &= ~BIT0; | |
| taskrun = taskstackpnt; | |
| alt_stack_space = (unsigned *) 0xff00-(STACK_WORD_SIZE); | |
| register unsigned *multistack = &alt_stack_space[STACK_WORD_SIZE]; | |
| register unsigned *p = multistack; | |
| register unsigned i=0; | |
| while( i < tasks-1 ) { | |
| multistack -= stacksize[i]; // adjust stack to accomodate n stack words | |
| *(multistack) = (unsigned)taskpnt[++i]; // prefill in PC | |
| *(multistack-1) = GIE; // prefill in SR | |
| taskstackpnt[i] = (unsigned) | |
| (multistack-((MIN_STACK_WORDS)-1)); // point at dummy stack words | |
| } | |
| //WDTCTL = WDT_MDLY_32; // 4ms tick using MCLK | |
| //WDTCTL = WDT_MDLY_8;; // 1ms tick using MCLK | |
| WDTCTL = WDT_MDLY_0_5; // 1/16ms tick using MCLK | |
| SFRIE1 |= WDTIE; | |
| #if 1 | |
| __enable_interrupt(); | |
| #else | |
| __asm__ volatile (" eint\n nop\n"); | |
| #endif | |
| __asm__ volatile ( | |
| " mov %1, r1\n" // set stack pointer to fram | |
| " br 0(%0)\n" // indirect jmp to first task | |
| :: | |
| "r" (taskpnt) | |
| ,"r" (p) | |
| ); | |
| } | |
| //============= TASK SWITCHER ISR ============= | |
| __attribute__((interrupt(WDT_VECTOR), naked, used)) | |
| void taskswitcher(void); | |
| void taskswitcher(void) | |
| { | |
| __asm__ volatile ("xor.b #1,%0" :: "m" (P3OUT) ); // measure overhead | |
| // push r15-r5 | |
| __asm__ volatile ("pushm %0, r15" :: "i" (SAVED_STACK_WORDS)); | |
| #if 0 | |
| ++systick; | |
| #else | |
| __asm__ volatile (" inc %A0\n" :: "m" (systick)); | |
| __asm__ volatile (" adc %B0\n" :: "m" (systick)); | |
| #endif | |
| __asm__ volatile ( | |
| " mov r1, 0(%2)\n" | |
| " incd %2\n" | |
| " cmp %0, %2\n" | |
| " jnz 1f\n" | |
| " mov %1, %2\n" | |
| "1:\n" | |
| " mov 0(%2), r1\n" | |
| ::"i" (taskstackpnt+tasks) | |
| ,"i" (taskstackpnt) | |
| ,"r" (taskrun) | |
| ); | |
| // pop r5-r15 | |
| __asm__ volatile ("popm %0, r15" :: "i" (SAVED_STACK_WORDS)); | |
| __asm__ volatile ("xor.b #1,%0" :: "m" (P3OUT) ); | |
| __asm__ volatile ("reti\n"); | |
| } | |
| #-------------------------------------------------------------------- | |
| # Makefile - for tiny msp430 preemptive kernel | |
| TARGET = tinyos.elf | |
| # point this to where your CCS is installed | |
| CCS_PATH =? $(HOME)/ti/ccsv6 | |
| #ARCH ?= msp430-elf- | |
| ARCH ?= msp430- | |
| CPU ?= msp430g2553 | |
| OPTIMIZE ?= s | |
| VERBOSE ?= | |
| COMM_OBJS = task1.o task2.o task3.o sys.o | |
| ALL_OBJS = $(COMM_OBJS) task4.o main.o main_fr5969.o | |
| ifeq ($(CPU),msp430g2553) | |
| DEBUG_TARGET ?= rf2500 | |
| HWMULT = none | |
| OBJS = main.o | |
| else | |
| DEBUG_TARGET ?= tilib | |
| HWMULT ?= f5series | |
| OBJS = task4.o main_fr5969.o | |
| endif | |
| CC = $(ARCH)gcc | |
| LD = $(ARCH)gcc | |
| SIZE = $(ARCH)size | |
| OBJDUMP = $(ARCH)objdump | |
| READELF = $(ARCH)readelf | |
| TARGETBASE = $(patsubst %.elf,%,$(TARGET)) | |
| LSSFILE = $(TARGETBASE).lss | |
| CFLAGS = $(VERBOSE) -g -O$(OPTIMIZE) -mmcu=$(CPU) | |
| CFLAGS += -fdata-sections -ffunction-sections | |
| CFLAGS += -Wall -Wno-main | |
| ifeq ($(ARCH),msp430-elf-) | |
| CFLAGS += -gdwarf-3 -gstrict-dwarf | |
| CFLAGS += -I $(CCS_PATH)/ccs_base/msp430/include_gcc | |
| CFLAGS += -I $(CCS_PATH)/tools/compiler/gcc_msp430_4.9.14r1_467/msp430-elf/include | |
| CFLAGS += -mhwmult=$(HWMULT) | |
| CFLAGS += -fomit-frame-pointer | |
| CFLAGS += -ffixed-R4 | |
| CFLAGS += -minrt | |
| else | |
| CFLAGS += -D__get_SP_register=__read_stack_pointer | |
| CFLAGS += -D__set_SP_register=__write_stack_pointer | |
| CFLAGS += -fomit-frame-pointer | |
| CFLAGS += -ffixed-r4 | |
| endif | |
| LDFLAGS = -mmcu=$(CPU) | |
| ifeq ($(ARCH),msp430-elf-) | |
| LDFLAGS += -Wl,-Map,"$(TARGETBASE).map" | |
| LDFLAGS += -L /mnt/vbox/shared/ti_62/ccsv6/ccs_base/msp430/include_gcc | |
| LDFLAGS += -T $(CPU).ld | |
| LDFLAGS += -gdwarf-3 -gstrict-dwarf | |
| LDFLAGS += $(VERBOSE) | |
| else | |
| LDFLAGS += -Wl,-gc-section,-Map,"$(TARGETBASE).map" | |
| LDFLAGS += -mdisable-watchdog | |
| endif | |
| .phony: all clean install debug showmacros updatefw | |
| all: $(TARGET) | |
| $(SIZE) $^ | |
| $(TARGET): $(COMM_OBJS) $(OBJS) | |
| $(CC) $(LDFLAGS) -o $@ $^ | |
| $(OBJDUMP) -CS $@ > $(LSSFILE) | |
| $(READELF) -x .rodata $@ >> $(LSSFILE) | |
| clean: | |
| rm -f $(TARGET) $(ALL_OBJS) $(LSSFILE) | |
| rm -f $(TARGETBASE).hex $(TARGETBASE).cycles $(TARGETBASE).map | |
| install: tinyos.elf | |
| mspdebug $(DEBUG_TARGET) "prog $?" | |
| debug: | |
| xterm -e "$(ARCH)gdb -ex 'target remote :2000' $(TARGET)" & | |
| xterm -e "mspdebug $(DEBUG_TARGET) gdb" & | |
| updatefw: | |
| mspdebug --allow-fw-update tilib | |
| showmacros: | |
| $(CC) $(CFLAGS) -include "msp430.h" -v -dM -E - </dev/null | sort | less |
| /* | |
| * sys_xxx - helper routines | |
| * | |
| * Rick Kimball (C) 2016 | |
| */ | |
| #include "common.h" | |
| extern volatile systick_t systick; | |
| inline systick_t sys_tick_count(void) { return systick; } | |
| void sys_delay(systick_t msecs) | |
| { | |
| systick_t start = sys_tick_count(); | |
| //msecs <<= 4; | |
| while ( (sys_tick_count() - start) < msecs) { | |
| ; | |
| } | |
| } |
| /* | |
| * sys.h | |
| */ | |
| #ifndef SYS_H_ | |
| #define SYS_H_ | |
| typedef unsigned long systick_t; | |
| void sys_delay(systick_t msecs); | |
| #endif | |
| #include "common.h" | |
| void task1(void) { | |
| volatile unsigned count=0; // 4 bytes on stack | |
| P1DIR |= BIT0; | |
| P1OUT &= ~BIT0; | |
| while(1){ | |
| P1OUT ^= BIT0; | |
| #if 1 | |
| __delay_cycles(50*(4000000/1000)); | |
| #else | |
| sys_delay(50); | |
| #endif | |
| P1OUT ^= BIT0; | |
| #if 1 | |
| __delay_cycles(450*(4000000/1000)); | |
| #else | |
| sys_delay(450); // 4+2 bytes of stack used | |
| #endif | |
| ++count; | |
| } | |
| } |
| #include "common.h" | |
| #ifdef __MSP430FR5969__ | |
| #define PORTDIR P4DIR | |
| #define PORTOUT P4OUT | |
| #else | |
| #define PORTDIR P1DIR | |
| #define PORTOUT P1OUT | |
| #endif | |
| void task2(void){ | |
| volatile unsigned long count=0; // 4 bytes of stack | |
| PORTDIR |= BIT6; | |
| while(1){ | |
| PORTOUT |= BIT6; | |
| sys_delay(25); // 4+2 bytes of stack | |
| PORTOUT &=~BIT6; | |
| sys_delay(100); // 4+2 bytes of stack | |
| ++count; | |
| } | |
| } |
| #include "common.h" | |
| unsigned int fibo(int); | |
| void task3(void){ | |
| int temp = 0; | |
| while(1){ | |
| fibo(++temp); | |
| } | |
| } | |
| unsigned int fibo(int n){ | |
| if (n < 2) | |
| return n; | |
| else | |
| return (fibo(n-1) + fibo(n-2)); | |
| } | |
| #include "common.h" | |
| void task4(void) { | |
| volatile unsigned count=0; | |
| P2DIR |= BIT4; | |
| P2OUT &= ~BIT4; | |
| while(1){ | |
| P2OUT ^= BIT4; | |
| sys_delay(10); | |
| P2OUT ^= BIT4; | |
| sys_delay(10); | |
| ++count; | |
| } | |
| } |