Finished adding untested bare functionality vfs

Finished adding untested shm syscalls.
Finished adding untested l4 send/recv helpers

Everything compiles. Now going to fix lots of bugs ;-)

tasks/fs0/src/syscalls.c

@@ -0,0 +1,95 @@
+/*
+ * Some syscall stubs
+ *
+ * Copyright (C) 2008 Bahadir Balban
+ */
+#include <l4/api/errno.h>
+#include <l4lib/types.h>
+#include <l4lib/ipcdefs.h>
+#include <l4lib/arch/syscalls.h>
+#include <l4lib/arch/syslib.h>
+#include <vfs.h>
+#include <lib/malloc.h>
+#include <string.h>
+#include <stdio.h>
+#include <task.h>
+
+/*
+ * This notifies mm0 that this is the fd that refers to this vnode number
+ * from now on.
+ *
+ * MM0 *also* keeps track of fd's because mm0 is a better candidate
+ * for handling syscalls that access file content (i.e. read/write) since
+ * it maintains the page cache.
+ */
+int send_pager_opendata(l4id_t sender, int fd, unsigned long vnum)
+{
+	int err;
+
+	write_mr(L4SYS_ARG0, sender);
+	write_mr(L4SYS_ARG1, fd);
+	write_mr(L4SYS_ARG2, vnum);
+
+	if ((err = l4_send(PAGER_TID, L4_IPC_TAG_OPENDATA)) < 0) {
+		printf("%s: L4 IPC Error: %d.\n", __FUNCTION__, err);
+		return err;
+	}
+
+	return 0;
+}
+
+int do_open(l4id_t sender, const char *pathname, int flags, unsigned int mode)
+{
+	struct vnode *v;
+	struct tcb *t;
+	int fd;
+
+	/* FIXME: Use strnlen */
+	char *pathcopy = kmalloc(strlen(pathname));
+	/* FIXME: Use strncpy */
+	memcpy(pathcopy, pathname, strlen(pathname));
+
+	/* Get the vnode */
+	if (IS_ERR(v = vfs_lookup(vfs_root.pivot->sb, pathcopy)))
+		return (int)v;
+
+	/* Get the task */
+	BUG_ON(!(t = find_task(sender)));
+
+	/* Get a new fd */
+	BUG_ON(!(fd = id_new(t->fdpool)));
+
+	/* Assign the new fd with the vnode's number */
+	t->fd[fd] = v->vnum;
+
+	/* Tell mm0 about opened vnode information */
+	BUG_ON(send_pager_opendata(sender, fd, v->vnum) < 0);
+
+	return 0;
+}
+
+/* FIXME:
+ * - Is it already open?
+ * - Allocate a copy of path string since lookup destroys it
+ * - Check flags and mode.
+ */
+int sys_open(l4id_t sender, const char *pathname, int flags, unsigned int mode)
+{
+	return do_open(sender, pathname, flags, mode);
+}
+
+int sys_read(l4id_t sender, int fd, void *buf, int count)
+{
+	return 0;
+}
+
+int sys_write(l4id_t sender, int fd, const void *buf, int count)
+{
+	return 0;
+}
+
+int sys_lseek(l4id_t sender, int fd, int offset, int whence)
+{
+	return 0;
+}
+