Feat: kernel thread done

kernel/include/thread.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <stddef.h>
+#include <queue.h>
+
+typedef int32_t (*thread_func_t)(uint64_t);
+
+typedef enum: uint32_t {
+  THREAD_STATUS_RUNABLE = 0,
+  THREAD_STATUS_WAIT = 1,
+  THREAD_STATUS_EXIT = 2,
+  THREAD_STATUS_ZOMBIE = 3,
+} thread_status_t;
+
+typedef struct {
+  uint64_t x19, x20;
+  uint64_t x21, x22;
+  uint64_t x23, x24;
+  uint64_t x25, x26;
+  uint64_t x27, x28;
+  uint64_t fp, lr;
+  uint64_t sp;
+  uint64_t sp_el0;
+  uint64_t elr_el1;
+} cpu_state_t;
+
+typedef struct {
+  thread_func_t func;
+  uint64_t param;
+
+  thread_status_t status;
+  int32_t retcode;
+
+  void *stack_pointer;
+  size_t stack_size;
+
+  cpu_state_t regs;
+} thread_t;
+
+// thread.S
+void context_switch(void *from, void *to, thread_t *th);
+
+// thread.c
+void thread_init(void);
+void run_thread(thread_func_t func, uint64_t param);
+void schedule(void);
+#define yield schedule
+
+thread_t *get_current(void);
+
+extern queue_t *global_run_queue;
+extern queue_t *global_wait_queue;
+extern queue_t *global_gc_queue;