A first step in writing a dynamically created bootfs for boot images.

tasks/fs0/include/fs.h

@@ -48,7 +48,7 @@ struct superblock_ops {
 
 struct dentry;
 struct file;
-struct filesystem;
+struct file_system_type;
 struct superblock;
 struct vnode;
 
@@ -80,13 +80,16 @@ struct vnode {
 	unsigned long size;		/* Total size of vnode in bytes */
 };
 
-struct filesystem {
-	unsigned long magic;
+struct file_system_type {
 	char name[256];
+	unsigned long magic;
+	unsigned int flags;
+	struct superblock *(*get_sb)(void);
+	struct list_head sb_list;
 };
 
 struct superblock {
-	struct filesystem fs;
+	struct file_system_type fs;
 	struct superblock_ops ops;
 	struct dentry *root_dirent;
 };

tasks/fs0/src/bootfs/bootfs.c

@@ -0,0 +1,82 @@
+/*
+ * An imaginary filesystem for reading the in-memory
+ * server tasks loaded out of the initial elf executable.
+ *
+ * Copyright (C) 2007, 2008 Bahadir Balban
+ */
+#include <fs.h>
+#include <l4/lib/list.h>
+
+/*
+ * These are preallocated structures for forging a filesystem tree
+ * from the elf loaded server segments available from kdata info.
+ */
+#define BOOTFS_IMG_MAX					10
+struct vnode bootfs_vnode[BOOTFS_IMG_MAX];
+struct dentry bootfs_dentry[BOOTFS_IMG_MAX];
+struct file bootfs_file[BOOTFS_IMG_MAX];
+
+/* These are for the root */
+struct dentry bootfs_root;
+struct vnode bootfs_rootvn;
+
+void bootfs_init_root(struct dentry *r)
+{
+	struct vnode *v = r->vnode;
+
+	/* Initialise dentry for rootdir */
+	r->refcnt = 0;
+	strcpy(r->name, "");
+	INIT_LIST_HEAD(&r->child);
+	INIT_LIST_HEAD(&r->children);
+	INIT_LIST_HEAD(&r->vref);
+	r->parent = r;
+
+	/* Initialise vnode for rootdir */
+	v->id = 0;
+	v->refcnt = 0;
+	INIT_LIST_HEAD(&v->dirents);
+	INIT_LIST_HEAD(&v->state_list);
+	list_add(&r->vref, &v->dirents);
+	v->size = 0;
+}
+
+struct superblock *bootfs_init_sb(struct superblock *sb)
+{
+	sb->root = &bootfs_root;
+	sb->root->vnode = &bootfs_rootvn;
+
+	bootfs_init_root(&sb->root);
+
+	return sb;
+}
+
+struct superblock bootfs_sb = {
+	.fs = bootfs_type,
+	.ops = {
+		.read_sb = bootfs_read_sb,
+		.write_sb = bootfs_write_sb,
+		.read_vnode = bootfs_read_vnode,
+		.write_vnode = bootfs_write_vnode,
+	},
+};
+
+struct superblock *bootfs_get_sb(void)
+{
+	bootfs_init_sb(&bootfs_sb);
+	return &bootfs_sb;
+}
+
+struct file_system_type bootfs_type = {
+	.name = "bootfs",
+	.magic = 0,
+	.get_sb = bootfs_get_sb,
+};
+
+void init_bootfs()
+{
+	struct superblock *sb;
+
+	sb = bootfs_type.get_sb();
+}
+

tasks/fs0/src/init.c

@@ -43,7 +43,7 @@ void init_root(struct vnode *root_vn, struct dentry *root_d)
 	root_vn->refcnt = 0;
 	INIT_LIST_HEAD(&root_vn->dirents);
 	INIT_LIST_HEAD(&root_vn->state_list);
-	list_add(&root_d->dref_list, &root_vn->dirents);
+	list_add(&root_d->vnlist, &root_vn->dirents);
 	root_vn->size = 0;
 
 	/* Initialise global struct rootdir ptr */

tasks/fs0/src/vfs.c

@@ -1,25 +0,0 @@
-
-#include <stdio.h>
-#include <l4/api/ipc.h>
-#include <l4lib/kip.h>
-#include <l4lib/arch/syscalls.h>
-
-/* Simply calls a wait ipc to sync with the given partner thread */
-void wait_task(l4id_t partner)
-{
-	u32 tag = L4_IPC_TAG_WAIT;
-	l4_ipc(partner, l4_nilthread, tag);
-	printf("%d synced with us.\n", (int)partner);
-}
-
-void mount_root(void)
-{
-	/*
-	 * We know the primary block device from compile-time.
-	 * It is expected to have the root filesystem.
-	 */
-	wait_task(BLKDEV_TID);
-
-	/* Set up a shared memory area with the block device */
-}
-