Thanks！For me https://pdos.csail.mit.edu/6.S081/2020/xv6/book-riscv-rev1.pdf https://pdos.csail.mit.edu/6.S081/2020/xv6/book-riscv-rev1.p... was quite helpful!

Thanks！For me https://pdos.csail.mit.edu/6.S081/2020/xv6/book-riscv-rev1.pdf https://pdos.csail.mit.edu/6.S081/2020/xv6/book-riscv-rev1.p... was quite helpful! but Someday I will write a book on how to implement this OS step by step in Japanese.