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syscalls.c
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syscalls.c
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#include "MK20D10.h"
#include <sys/stat.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <sys/times.h>
extern int errno;
extern int __io_putchar(int ch) __attribute__((weak));
extern int __io_getchar(void) __attribute__((weak));
register char *stack_ptr asm("sp");
char *__env[1]={ 0 };
char **environ=__env;
void _init(void)
{
}
void initialise_monitor_handles()
{
}
int _getpid(void)
{
return 1;
}
int _kill(int pid, int sig)
{
errno=EINVAL;
return -1;
}
void _exit(int status)
{
_kill(status, -1);
while(1);
}
int _read(int file, char *ptr, int len)
{
int DataIdx;
for(DataIdx=0;DataIdx<len;DataIdx++)
*ptr++=__io_getchar();
return len;
}
int _write(int file, char *ptr, int len)
{
int DataIdx;
for(DataIdx=0;DataIdx<len;DataIdx++)
__io_putchar(*ptr++);
return len;
}
caddr_t _sbrk(int incr)
{
extern char end asm("end");
static char *heap_end;
char *prev_heap_end;
if(heap_end==0)
heap_end=&end;
prev_heap_end=heap_end;
if(heap_end+incr>stack_ptr)
{
errno=ENOMEM;
return (caddr_t)-1;
}
heap_end+=incr;
return (caddr_t)prev_heap_end;
}
int _close(int file)
{
return -1;
}
int _fstat(int file, struct stat *st)
{
st->st_mode=S_IFCHR;
return 0;
}
int _isatty(int file)
{
return 1;
}
int _lseek(int file, int ptr, int dir)
{
return 0;
}
int _open(char *path, int flags, ...)
{
return -1;
}
int _wait(int *status)
{
errno=ECHILD;
return -1;
}
int _unlink(char *name)
{
errno=ENOENT;
return -1;
}
int _times(struct tms *buf)
{
return -1;
}
int _stat(char *file, struct stat *st)
{
st->st_mode=S_IFCHR;
return 0;
}
int _link(char *old, char *new)
{
errno=EMLINK;
return -1;
}
int _fork(void)
{
errno=EAGAIN;
return -1;
}
int _execve(char *name, char **argv, char **env)
{
errno=ENOMEM;
return -1;
}
volatile extern uint32_t Tick;
// Ripped from Teensyduino
uint32_t micros(void)
{
uint32_t count, current, istatus;
__asm__ volatile ("CPSID i");
current=SysTick->VAL;
count=Tick;
istatus=SCB->ICSR;
__asm__ volatile ("CPSIE i");
if((istatus&SCB_ICSR_PENDSTSET_Msk)&¤t>50)
count++;
current=((72000000/1000)-1)-current;
return count*1000+current/(72000000/1000000);
}
// Ripped from Teensyduino
void DelayMS(uint32_t ms)
{
uint32_t start=micros();
if(ms>0)
{
while(1)
{
while((micros()-start)>=1000)
{
ms--;
if(ms==0)
return;
start+=1000;
}
}
}
}
// Ripped from Teensyduino
void DelayUS(uint32_t usec)
{
uint32_t n=usec*24; // 72MHz
if(n==0)
return;
__asm__ volatile(
"L_%=_delayMicroseconds:\n"
"subs %0, #1\n"
"bne L_%=_delayMicroseconds\n"
: "+r" (n) : );
}