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, 65 insertions, 0 deletions

diff --git a/kern/task.c b/kern/task.c
new file mode 100644
index 0000000..d333776
--- /dev/null
+++ b/kern/task.c
@@ -0,0 +1,65 @@
+/*
+ * 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/>.
+ */
+
+#include <kern/init.h>
+#include <kern/kmem.h>
+#include <kern/list.h>
+#include <kern/stddef.h>
+#include <kern/string.h>
+#include <kern/task.h>
+#include <kern/thread.h>
+#include <vm/vm_kmem.h>
+
+/*
+ * Kernel task and storage.
+ */
+static struct task kernel_task_store;
+struct task *kernel_task = &kernel_task_store;
+
+/*
+ * Cache for allocated tasks.
+ */
+static struct kmem_cache task_cache;
+
+/*
+ * Global list of tasks.
+ */
+static struct list task_list;
+
+static void
+task_init(struct task *task, const char *name, struct vm_map *map)
+{
+    list_init(&task->threads);
+    task->map = map;
+    strlcpy(task->name, name, sizeof(task->name));
+}
+
+void __init
+task_setup(void)
+{
+    kmem_cache_init(&task_cache, "task", sizeof(struct task),
+                    0, NULL, NULL, NULL, 0);
+    task_init(kernel_task, "x15", kernel_map);
+    list_init(&task_list);
+    list_insert(&task_list, &kernel_task->node);
+}
+
+void
+task_add_thread(struct task *task, struct thread *thread)
+{
+    list_insert_tail(&task->threads, &thread->task_node);
+}