add character device to dump all kernel messages

fs/initrd.c

@@ -429,19 +429,21 @@ int initrd_init(void)
 	/* create the directory bin and dev */
 	mkdir_fs(fs_root, "bin");
 	mkdir_fs(fs_root, "sbin");
-	mkdir_fs(fs_root, "var");
 	tmp = mkdir_fs(fs_root, "dev");
 	/* create the character device "null" */
 	null_init(tmp, "null");
-	/* create the standart input device "stdin" */
+	/* create the standard input device "stdin" */
 	stdin_init(tmp, "stdin");
-	/* create the standart output device "stdout" */
+	/* create the standard output device "stdout" */
 	stdout_init(tmp, "stdout");
-	/* create the standart error-output device "stderr" */
+	/* create the standard error-output device "stderr" */
 	stderr_init(tmp, "stderr");
-	/* create the standart device "netchar" */
+	/* create the standard device "socket" */
 	socket_init(tmp, "socket");
 
+	/* create the character device "kmessages" */
+	tmp = mkdir_fs(fs_root, "var");
+	kmsg_init(tmp, "kmessages");
 
 	/* For every module.. */
 #ifdef CONFIG_MULTIBOOT

include/metalsvm/stdio.h

@@ -74,6 +74,12 @@ int koutput_init(void);
  */
 int kvprintf(char const *fmt, void (*func) (int, void *), void *arg, int radix, va_list ap);
 
+struct vfs_node;
+/**
+ * Init function to create a character device which represents all kernel messages
+ */
+int kmsg_init(struct vfs_node* node, const char *name);
+
 /** @brief Set a new foreground color for kprintf and kputchar.
  *
  * The color change will affect any procedure using vga_putchar()/vga_puts().

libkern/stdio.c

@@ -1,22 +1,23 @@
-/* 
+/*
- * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
+ * Copyright 2010 Stefan Lankes, Chair for Operating Systems, 
  *                               RWTH Aachen University
- *
+ * 
- * Licensed under the Apache License, Version 2.0 (the "License");
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
- * you may not use this file except in compliance with the License.
+ * use this file except in compliance with the License. You may obtain a copy
- * You may obtain a copy of the License at
+ * of the License at
- *
+ * 
- *     http://www.apache.org/licenses/LICENSE-2.0
+ * http://www.apache.org/licenses/LICENSE-2.0
- *
+ * 
  * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * See the License for the specific language governing permissions and
+ * License for the specific language governing permissions and limitations
- * limitations under the License.
+ * under the License.
- *
+ * 
- *  This file is part of MetalSVM.
+ * This file is part of MetalSVM.
  */
 
+#include <metalsvm/stdlib.h>
 #include <metalsvm/stdio.h>
 #include <metalsvm/string.h>
 #include <metalsvm/stdarg.h>
@@ -43,6 +44,100 @@ static uint32_t early_print = NO_EARLY_PRINT;
 static atomic_int32_t kmsg_counter = ATOMIC_INIT(0);
 static unsigned char kmessages[KMSG_SIZE] __attribute__ ((section(".kmsg"))) = {[0 ... KMSG_SIZE-1] = 0x00};
 
+static ssize_t kmsg_read(fildes_t* file, uint8_t* buffer, size_t size)
+{
+	size_t start, i = 0;
+
+	if (BUILTIN_EXPECT(!buffer, 0))
+		return -EINVAL;
+	if (BUILTIN_EXPECT(!size, 0))
+		return 0;
+
+	if (kmessages[(atomic_int32_read(&kmsg_counter) + 1) % KMSG_SIZE] == 0)
+		start = 0;
+	else
+		start = atomic_int32_read(&kmsg_counter);
+
+	if (((start + file->offset) % KMSG_SIZE) == atomic_int32_read(&kmsg_counter))
+		return 0;
+
+	for(i=0; i<size; i++, file->offset++) {
+		buffer[i] = kmessages[(start + file->offset) % KMSG_SIZE];
+		if (((start + file->offset) % KMSG_SIZE) == atomic_int32_read(&kmsg_counter))
+			return i;
+	}
+
+	return size;
+}
+
+static int kmsg_open(fildes_t* file, const char *name)
+{
+	return 0;
+}
+
+static int kmsg_close(fildes_t* file)
+{
+	return 0;
+}
+
+/* Init Functions */
+int kmsg_init(vfs_node_t * node, const char *name)
+{
+	uint32_t	i, j;
+	vfs_node_t*	new_node;
+	dir_block_t*	blockdir;
+	dirent_t*	dirent;
+	block_list_t*	blist;
+
+	if (BUILTIN_EXPECT(!node || !name, 0))
+		return -EINVAL;
+
+	if (BUILTIN_EXPECT(node->type != FS_DIRECTORY, 0))
+		return -EINVAL;
+
+	if (finddir_fs(node, name))
+		return -EINVAL;
+
+	new_node = kmalloc(sizeof(vfs_node_t));
+	if (BUILTIN_EXPECT(!new_node, 0))
+		return -ENOMEM;
+
+	memset(new_node, 0x00, sizeof(vfs_node_t));
+	new_node->type = FS_CHARDEVICE;
+	new_node->open = &kmsg_open;
+	new_node->close = &kmsg_close;
+	new_node->read = &kmsg_read;
+	new_node->write = NULL;
+	spinlock_init(&new_node->lock);
+
+	blist = &node->block_list;
+	do {
+		for (i = 0; i < MAX_DATABLOCKS; i++) {
+			if (blist->data[i]) {
+				blockdir = (dir_block_t *) blist->data[i];
+				for (j = 0; j < MAX_DIRENTRIES; j++) {
+					dirent = &blockdir->entries[j];
+					if (!dirent->vfs_node) {
+						dirent->vfs_node = new_node;
+						strncpy(dirent->name, name, MAX_FNAME);
+						return 0;
+					}
+				}
+			}
+		}
+
+		if (!blist->next) {
+			blist->next = (block_list_t *) kmalloc(sizeof(block_list_t));
+			if (blist->next)
+				memset(blist->next, 0x00, sizeof(block_list_t));
+		}
+	} while (blist);
+
+	kfree(new_node, sizeof(vfs_node_t));
+
+	return -ENOMEM;
+}
+
 int koutput_init(void)
 {
 #ifdef CONFIG_VGA
@@ -60,11 +155,11 @@ int kputchar(int c)
 	kmessages[pos % KMSG_SIZE] = (unsigned char) c;
 #ifdef CONFIG_VGA
 	if (early_print == VGA_EARLY_PRINT)
-		vga_putchar(c);	
+		vga_putchar(c);
-#endif 
+#endif
 #ifdef CONFIG_UART
 	if (early_print == UART_EARLY_PRINT)
-		uart_putchar(c);	
+		uart_putchar(c);
 #endif
 
 	return 1;