Add support for static tcb, applications in some special case can initialize system resources in advance through static tcb. | static struct task_tcb_s g_tcb; | | memset(&g_tcb, 0, sizeof(struct task_tcb_s)); | g_tcb.cmn.flags = TCB_FLAG_TTYPE_KERNEL; | nxtask_init(&g_tcb, "PTCB", 101, NULL, 1024, ptcb_task, NULL, NULL, NULL); | | ... | nxtask_activate(&g_tcb.cmn); Signed-off-by: chao an <anchao@lixiang.com>