kern/init.c

   1 /* See COPYRIGHT for copyright information. */
   2
   3 #include <inc/stdio.h>
   4 #include <inc/string.h>
   5 #include <inc/assert.h>
   6
   7 #include <kern/monitor.h>
   8 #include <kern/console.h>
   9
  10 // Test the stack backtrace function (lab 1 only)
  11 void
  12 test_backtrace(int x)
  13 {
  14         cprintf("entering test_backtrace %d\n", x);
  15         if (x > 0)
  16                 test_backtrace(x-1);
  17         else
  18                 mon_backtrace(0, 0, 0);
  19         cprintf("leaving test_backtrace %d\n", x);
  20 }
  21
  22 void
  23 i386_init(void)
  24 {
  25         extern char edata[], end[];
  26
  27         // Before doing anything else, complete the ELF loading process.
  28         // Clear the uninitialized global data (BSS) section of our program.
  29         // This ensures that all static/global variables start out zero.
  30         memset(edata, 0, end - edata);
  31
  32         // Initialize the console.
  33         // Can't call cprintf until after we do this!
  34         cons_init();
  35
  36         cprintf("6828 decimal is %o octal!\n", 6828);
  37
  38
  39
  40
  41
  42
  43
  44         // Test the stack backtrace function (lab 1 only)
  45         test_backtrace(5);
  46
  47         // Drop into the kernel monitor.
  48         while (1)
  49                 monitor(NULL);
  50 }
  51
  52
  53 /*
  54  * Variable panicstr contains argument to first call to panic; used as flag
  55  * to indicate that the kernel has already called panic.
  56  */
  57 static const char *panicstr;
  58
  59 /*
  60  * Panic is called on unresolvable fatal errors.
  61  * It prints "panic: mesg", and then enters the kernel monitor.
  62  */
  63 void
  64 _panic(const char *file, int line, const char *fmt,...)
  65 {
  66         va_list ap;
  67
  68         if (panicstr)
  69                 goto dead;
  70         panicstr = fmt;
  71
  72         va_start(ap, fmt);
  73         cprintf("kernel panic at %s:%d: ", file, line);
  74         vcprintf(fmt, ap);
  75         cprintf("\n");
  76         va_end(ap);
  77
  78 dead:
  79         /* break into the kernel monitor */
  80         while (1)
  81                 monitor(NULL);
  82 }
  83
  84 /* like panic, but don't */
  85 void
  86 _warn(const char *file, int line, const char *fmt,...)
  87 {
  88         va_list ap;
  89
  90         va_start(ap, fmt);
  91         cprintf("kernel warning at %s:%d: ", file, line);
  92         vcprintf(fmt, ap);
  93         cprintf("\n");
  94         va_end(ap);
  95 }