Various fixes and improvements.

- fixed bug that caused IDLE to panic (irq hook inconsistency);
- kprintf() now accepts multiple arguments; moved to utility.c;
- prepare_shutdown() signals system processes with SIGKSTOP;
- phys_fill() renamed to phys_memset(), argument order changed;
- kmemset() removed in favor of phys_kmemset();
- kstrncpy() removed in favor of phys_copy();
- katoi, kstrncmp replaced by normal library procedure again;
- rm_irq_handler() interface changed (simply pass hook pointer);

kernel/utility.c

@@ -1,34 +1,143 @@
 /* This file contains a collection of miscellaneous procedures:
- *   panic	    abort MINIX due to a fatal error
+ *     panic:	        abort MINIX due to a fatal error
+ *     kprintf:		diagnostic output for the kernel 
+ *
+ * Changes:
+ *                      simple printing to circular buffer  (Jorrit N. Herder)
+ * 
+ * This file contains the routines that take care of kernel messages, i.e.,
+ * diagnostic output within the kernel. Kernel messages are not directly
+ * displayed on the console, because this must be done by the PRINT driver. 
+ * Instead, the kernel accumulates characters in a buffer and notifies the
+ * output driver when a new message is ready. 
  */
 
 #include "kernel.h"
-#include "assert.h"
 #include <unistd.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <signal.h>
 #include <minix/com.h>
 
+#define END_OF_KMESS 	-1
+FORWARD _PROTOTYPE(void kputc, (int c));
 
 
 /*===========================================================================*
  *                                   panic                                   *
  *===========================================================================*/
-PUBLIC void panic(s,n)
-_CONST char *s;
-int n;
+PUBLIC void panic(mess,nr)
+_CONST char *mess;
+int nr;
 {
 /* The system has run aground of a fatal kernel error. Terminate execution. */
   static int panicking = 0;
   if (panicking ++) return;		/* prevent recursive panics */
 
-  if (s != NULL) {
-	kprintf("\nKernel panic: %s", karg(s));
-	if (n != NO_NUM) kprintf(" %d", n);
+  if (mess != NULL) {
+	kprintf("\nKernel panic: %s", mess);
+	if (nr != NO_NUM) kprintf(" %d", nr);
 	kprintf("\n",NO_NUM);
   }
   prepare_shutdown(RBT_PANIC);
 }
 
 
+/*===========================================================================*
+ *				kprintf					     *
+ *===========================================================================*/
+PUBLIC void kprintf(const char *fmt, ...) 	/* format to be printed */
+{
+  int c;					/* next character in fmt */
+  unsigned long u;				/* hold number argument */
+  int base;					/* base of number arg */
+  int negative = 0;				/* print minus sign */
+  static char x2c[] = "0123456789ABCDEF";	/* nr conversion table */
+  char ascii[8 * sizeof(long) / 3 + 2];		/* string for ascii number */
+  char *s = NULL;				/* string to be printed */
+  va_list argp;					/* optional arguments */
+  
+  va_start(argp, fmt);				/* init variable arguments */
+
+  while((c=*fmt++) != 0) {
+
+      if (c == '%') {				/* expect format '%key' */
+          switch(c = *fmt++) {			/* determine what to do */
+
+          /* Known keys are %d, %u, %x, %s, and %%. This is easily extended 
+           * with number types like %b and %o by providing a different base.
+           * Number type keys don't set a string to 's', but use the general
+           * conversion after the switch statement.
+           */ 
+          case 'd':				/* output decimal */
+              u = va_arg(argp, int);
+              if (u < 0) { negative = 1; u = -u; }
+              base = 10;
+              break;
+          case 'u':				/* output unsigned long */
+              u = va_arg(argp, unsigned long);
+              base = 10;
+              break;
+          case 'x':				/* output hexadecimal */
+              u = va_arg(argp, unsigned long);
+              base = 0x10;
+              break;
+          case 's': 				/* output string */
+              s = va_arg(argp, char *);
+              if (s == NULL) s = "(null)";
+              break;
+          case '%':				/* output percent */
+              s = "%";				 
+              break;			
+
+          /* Unrecognized key. */
+          default:				/* echo back %key */
+              s = "%?";				
+              s[1] = c;				/* set unknown key */
+          }
+
+          /* Assume a number if no string is set. Convert to ascii. */
+          if (s == NULL) {
+              s = ascii + sizeof(ascii)-1;
+              *s = 0;			
+              do {  *--s = x2c[(u % base)]; }	/* work backwards */
+              while ((u /= base) > 0); 
+          }
+
+          /* This is where the actual output for format "%key" is done. */
+          if (negative) kputc('-');  		/* print sign if negative */
+          while(*s != 0) { kputc(*s++); }	/* print string/ number */
+      }
+      else {
+          kputc(c);				/* print and continue */
+      }
+  }
+  kputc(END_OF_KMESS);				/* terminate output */
+  va_end(argp);					/* end variable arguments */
+}
+
+
+/*===========================================================================*
+ *			            kputc				     *
+ *===========================================================================*/
+PRIVATE void kputc(c)
+int c;					/* character to append */
+{
+/* Accumulate a single character for a kernel message. Send a notification
+ * the to PRINTF_PROC driver if an END_OF_KMESS is encountered. 
+ */
+  if (c != END_OF_KMESS) {
+      kmess.km_buf[kmess.km_next] = c;	/* put normal char in buffer */
+      if (kmess.km_size < KMESS_BUF_SIZE)
+          kmess.km_size += 1;		
+      kmess.km_next = (kmess.km_next + 1) % KMESS_BUF_SIZE;
+  } else {
+      send_sig(PRINTF_PROC, SIGKMESS);
+  }
+}
+
+
 
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