C Strings and C Startup

C Strings

In C a string is an array of characters, but instead of having a size it is terminated by a null character.

char maxC = '\0' ;
char *nextC = &buff[0] ;
while (*nextC != '\0') {
   if (*nextC > maxC) {
      maxC = *nextC ;
   }
   ++nextC ;
}

C startup with crt0

• Initialize the stack
• Initialize global variables
  • Copied from program memory on the PIC
• Clear uninitialized global variables
• Load and link shared libraries
  • Only for larger systems
  • May be done by the operating system
  • May be delayed until libraries are used
• Get ready to call main
  • Set up the parameters
• Call main
• Return after the call