1 files changed, 63 insertions, 0 deletions
diff --git a/src/kernel/task.h b/src/kernel/task.h
new file mode 100644
index 0000000..3d331ae
--- /dev/null
+++ b/src/kernel/task.h
@@ -0,0 +1,63 @@
+/**
+ * @file task.h
+ * Provides multitasking functionality
+ *
+ * Copyright (C) 2018 Clyne Sullivan
+ *
+ * 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 <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef TASK_H_
+#define TASK_H_
+
+#include <stdint.h>
+
+/**
+ * A structure to contain task data.
+ */
+typedef struct {
+	void *next;      /**< pointer to the next task_t instance */
+	uint32_t *stack; /**< pointer to the task's stack */
+	uint32_t *sp;    /**< pointer to the task's last sp register value */
+} task_t;
+
+/**
+ * Enters multitasking mode. The given function acts as the initial thread.
+ * This task is given a 4kb stack.
+ * @param init the initial thread to run
+ */
+void task_init(void (*init)(void));
+
+/**
+ * Starts a new task.
+ * @param task the code to run
+ * @param stackSize how many bytes of stack to give the thread
+ */
+void task_start(void (*task)(void), uint16_t stackSize);
+
+/**
+ * Allows task switching to be disabled, for low-level actions.
+ * Multiple holds can be placed, and all must be removed to continue task
+ * switching.
+ * @param hold non-zero for hold, zero to remove hold
+ */
+void task_hold(uint8_t hold);
+
+/**
+ * Frees the task's resources and removes it from the running task list.
+ * @param code An unused exit code
+ */
+void _exit(int code);
+
+#endif // TASK_H_