What is the root of Hakka dialect?

First, anyone who speaks Hakka (Xinmin) is a Hakka. This is divided by language. Secondly, anyone who lives in a Hakka settlement is a Hakka. This is divided according to the regional theory. Third, the Han people whose ancestors moved south from the Central Plains (including the Heluo area in Shaanxi, Gansu, Shanxi and Henan) are all Hakkas. This is divided according to the root theory. Fourth, all Hakka descendants are Hakka. This is divided according to the theory of bloodline. Fifth, the migrating guests are all Hakkas. This is the basis for recording "subject and object" in various local chronicles. This is divided according to the migration theory of Hakkas. Sixth, anyone with Hakka customs is a Hakka. This is divided according to the theory of customs. Customs and habits include wedding ceremonies, program customs, culture, art, costumes, architecture, etc. Seventh, all guests with Hakka spiritual consciousness are Hakka, which is divided according to the theory of spiritual consciousness. His spiritual consciousness includes Confucian culture, thoughts, feelings, religion, respect for education, farming and reading, patriotism, hard work, pioneering and enterprising, thrift and so on. The eighth argument is that anyone who identifies himself as a Hakka is a Hakka. This is divided according to the sense of identity. I don't think Hakkas refer to immigrants from a single ethnic group (there are also immigrants from other ethnic minorities), but they are called Hakkas because they don't live in their ancestral homes. )