various templates of makefile
kexec debug: 1: 检查 grub crashkernel 2: 检查 /proc/iomem 3: 检查 /sys/kernel/kexec_crash_loaded 4: 检查 systemctl status kdump, 修改 /etc/kdump.conf, restart kdump.service 5: 解压 /boot/initramfs-version-kdump.img 中的 /etc/kdump.conf 查看 service, scripts. 6: 进入 2nd kernel shell, 查看 log