common.c

// common.c -- Defines some global functions.
#include "defs.h"
#include "common.h"


// Write len copies of val into dest.
void memset(void *dest, int val, uint32_t len)
{
    uint8_t *temp = (uint8_t *)dest;
    for ( ; len != 0; len--) *temp++ = val;
}


void* memmove(void *dst, const void *src, uint32_t n)
{
  const char *s;
  char *d;

  s = src;
  d = dst;
  if(s < d && s + n > d){
    s += n;
    d += n;
    while(n-- > 0)
      *--d = *--s;
  } else
    while(n-- > 0)
      *d++ = *s++;

  return dst;
}

void*
memcpy(void *dst, const void *src, uint32_t n)
{
  return memmove(dst, src, n);
}

// Like strncpy but guaranteed to NUL-terminate.
char* safestrcpy(char *s, const char *t, int n)
{
  char *os;

  os = s;
  if(n <= 0)
    return os;
  while(--n > 0 && (*s++ = *t++) != 0)
    ;
  *s = 0;
  return os;
}

int strlen(char *s)
{
  int n;
  for ( n = 0 ; s[n]>0 ; n++ )
    ;
  return n;
}

int
strncmp(const char *p, const char *q, uint32_t n)
{
  while(n > 0 && *p && *p == *q)
    n--, p++, q++;
  if(n == 0)
    return 0;
  return (uint8_t)*p - (uint8_t)*q;
}

extern void panic(const char *message, const char *file, uint32_t line)
{
    // We encountered a massive problem and have to stop.
    asm volatile("cli"); // Disable interrupts.
		kprintf("PANIC(%s) at %s: %d\n", message, file, line);
    // trigger Bochs debug mode (magic instruction)
		asm volatile("xchg %bx, %bx");
}

extern void panic_assert(const char *file, uint32_t line, const char *desc)
{
    // An assertion failed, and we have to panic.
    asm volatile("cli"); // Disable interrupts.

    kprintf("ASSERTION-FAILED(%s) at %s: %d\n", desc, file, line);
    // trigger Bochs debug mode (magic instruction)
		asm volatile("xchg %bx, %bx");
		//for(;;);
}