scheduler logic moved to semaphore.*

scheduler.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2022 Oleg Borodin  <borodin@unix7.org>
+ *
+ */
+
+#ifndef SCHEDULER_H_QWERTY
+#define SCHEDULER_H_QWERTY
+
+#define SCHEDULER_NUM_TASKS 4
+#define TASK_STACK_SIZE     2048
+
+typedef struct {
+    void (*entry)(void);
+    void *stack;
+    unsigned stack_size;
+    uint32_t sp;
+    bool runnable;
+} task_t;
+
+typedef struct {
+    task_t tasks[SCHEDULER_NUM_TASKS];
+    uint8_t current_task;
+} scheduler_t;
+
+
+void scheduler_init(scheduler_t *scheduler);
+void scheduler_task(scheduler_t *scheduler, int task_no, void (*entry)(void));
+void scheduler_yield(void);
+
+#endif