Implement preliminary thread context

Three new modules are added :
 - kern/task: Tasks are thread groups and resource containers for their
   threads.
 - kern/thread: The well known scheduling unit.
 - x86/tcb: The architecture specific thread control block.

The kernel currently loads a single thread context on the main processor.

1 files changed, 58 insertions, 0 deletions

diff --git a/kern/task.h b/kern/task.h
new file mode 100644
index 00000000..319651db
--- /dev/null
+++ b/kern/task.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2012 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _KERN_TASK_H
+#define _KERN_TASK_H
+
+#include <kern/list.h>
+
+/*
+ * Forward declaration.
+ */
+struct thread;
+
+/*
+ * Task name buffer size.
+ */
+#define TASK_NAME_SIZE 32
+
+/*
+ * Task structure.
+ */
+struct task {
+    struct list node;
+    struct list threads;
+    struct vm_map *map;
+    char name[TASK_NAME_SIZE];
+};
+
+/*
+ * The kernel task.
+ */
+extern struct task *kernel_task;
+
+/*
+ * Initialize the task module.
+ */
+void task_setup(void);
+
+/*
+ * Add a thread to a task.
+ */
+void task_add_thread(struct task *task, struct thread *thread);
+
+#endif /* _KERN_TASK_H */