split printf into a separate file, to make console.c more like a driver

1 files changed, 134 insertions, 0 deletions

diff --git a/kernel/printf.c b/kernel/printf.c
new file mode 100644
index 0000000..777cc5f
--- /dev/null
+++ b/kernel/printf.c
@@ -0,0 +1,134 @@
+//
+// formatted console output -- printf, panic.
+//
+
+#include <stdarg.h>
+
+#include "types.h"
+#include "param.h"
+#include "spinlock.h"
+#include "sleeplock.h"
+#include "fs.h"
+#include "file.h"
+#include "memlayout.h"
+#include "riscv.h"
+#include "defs.h"
+#include "proc.h"
+
+volatile int panicked = 0;
+
+// lock to avoid interleaving concurrent printf's.
+static struct {
+  struct spinlock lock;
+  int locking;
+} pr;
+
+static char digits[] = "0123456789abcdef";
+
+static void
+printint(int xx, int base, int sign)
+{
+  char buf[16];
+  int i;
+  uint x;
+
+  if(sign && (sign = xx < 0))
+    x = -xx;
+  else
+    x = xx;
+
+  i = 0;
+  do {
+    buf[i++] = digits[x % base];
+  } while((x /= base) != 0);
+
+  if(sign)
+    buf[i++] = '-';
+
+  while(--i >= 0)
+    consputc(buf[i]);
+}
+
+static void
+printptr(uint64 x)
+{
+  int i;
+  consputc('0');
+  consputc('x');
+  for (i = 0; i < (sizeof(uint64) * 2); i++, x <<= 4)
+    consputc(digits[x >> (sizeof(uint64) * 8 - 4)]);
+}
+
+// Print to the console. only understands %d, %x, %p, %s.
+void
+printf(char *fmt, ...)
+{
+  va_list ap;
+  int i, c, locking;
+  char *s;
+
+  locking = pr.locking;
+  if(locking)
+    acquire(&pr.lock);
+
+  if (fmt == 0)
+    panic("null fmt");
+
+  va_start(ap, fmt);
+  for(i = 0; (c = fmt[i] & 0xff) != 0; i++){
+    if(c != '%'){
+      consputc(c);
+      continue;
+    }
+    c = fmt[++i] & 0xff;
+    if(c == 0)
+      break;
+    switch(c){
+    case 'd':
+      printint(va_arg(ap, int), 10, 1);
+      break;
+    case 'x':
+      printint(va_arg(ap, int), 16, 1);
+      break;
+    case 'p':
+      printptr(va_arg(ap, uint64));
+      break;
+    case 's':
+      if((s = va_arg(ap, char*)) == 0)
+        s = "(null)";
+      for(; *s; s++)
+        consputc(*s);
+      break;
+    case '%':
+      consputc('%');
+      break;
+    default:
+      // Print unknown % sequence to draw attention.
+      consputc('%');
+      consputc(c);
+      break;
+    }
+  }
+
+  if(locking)
+    release(&pr.lock);
+}
+
+void
+panic(char *s)
+{
+  pr.locking = 0;
+  printf("panic: ");
+  printf(s);
+  printf("\n");
+  panicked = 1; // freeze other CPUs
+  for(;;)
+    ;
+}
+
+void
+printfinit(void)
+{
+  initlock(&pr.lock, "pr");
+  pr.locking = 1;
+}