Changeset c859753 in mainline for kernel/generic/src/console/console.c

Timestamp:

2008-06-03T14:55:09Z (17 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

419886f6

Parents:

aa48a9d

Message:

remove original klog
permanent kernel cyclic log buffer
proper printf formatting

File:

• kernel/generic/src/console/console.c (modified) (3 diffs)

kernel/generic/src/console/console.c

@@ -44 +44 @@
 #include <atomic.h>
 
-#define BUFLEN 2048
-static char debug_buffer[BUFLEN];
-static size_t offset = 0;
-/** Initialize stdout to something that does not print, but does not fail
- *
- * Save data in some buffer so that it could be retrieved in the debugger
- */
-static void null_putchar(chardev_t *d, const char ch)
-{
-        if (offset >= BUFLEN)
-                offset = 0;
-        debug_buffer[offset++] = ch;
-}
+#define KLOG_SIZE 4096
+
+/**< Kernel log cyclic buffer */
+static char klog[KLOG_SIZE];
+
+/**< First kernel log characters */
+static index_t klog_start = 0;
+/**< Number of valid kernel log characters */
+static size_t klog_len = 0;
+/**< Number of stored (not printed) kernel log characters */
+static size_t klog_stored = 0;
 
 static chardev_operations_t null_stdout_ops = {
-        .write = null_putchar
+        .suspend = NULL,
+        .resume = NULL,
+        .write = NULL,
+        .read = NULL
 };
 
@@ -91 +92 @@
                 /* no other way of interacting with user, halt */
                 if (CPU)
-                        printf("cpu%d: ", CPU->id);
+                        printf("cpu%u: ", CPU->id);
                 else
                         printf("cpu: ");
@@ -162 +163 @@
 void putchar(char c)
 {
+        if ((klog_stored > 0) && (stdout->op->write)) {
+                /* Print charaters stored in kernel log */
+                index_t i;
+                for (i = klog_len - klog_stored; i < klog_len; i++)
+                        stdout->op->write(stdout, klog[(klog_start + i) % KLOG_SIZE]);
+                klog_stored = 0;
+        }
+        
+        /* Store character in the cyclic kernel log */
+        klog[(klog_start + klog_len) % KLOG_SIZE] = c;
+        if (klog_len < KLOG_SIZE)
+                klog_len++;
+        else
+                klog_start = (klog_start + 1) % KLOG_SIZE;
+        
         if (stdout->op->write)
                 stdout->op->write(stdout, c);
+        else {
+                /* The character is just in the kernel log */
+                if (klog_stored < klog_len)
+                        klog_stored++;
+        }
 }