老友记！我顶你！

The Syslinux configuration file, syslinux.cfg, should be created in the same directory where you installed Syslinux. In our case, /boot/syslinux/ for BIOS systems and $esp/EFI/syslinux/ for UEFI systems. The bootloader will look for either syslinux.cfg (preferred) or extlinux.conf Tip: Instead of LINUX, the keyword KERNEL can also be used. KERNEL tries to detect the type of the file, while LINUX always expects a Linux kernel. TIMEOUT value is in units of 0.1 seconds. Examples Note: Any configuration file found in the examples needs to be edited to set the proper kernel parameters. See section #Kernel parameters. Please, pay close attention to the paths. The examples may not be suitable for your installation, especially when using UEFI. Boot prompt This is a simple configuration file that will show a boot: prompt and will automatically boot after 5 seconds. If you want to boot directly without seeing a prompt, set PROMPT to 0. Configuration: /boot/syslinux/syslinux.cfg PROMPT 1 TIMEOUT 50 DEFAULT arch  LABEL arch LINUX ../vmlinuz-linux APPEND root=/dev/sda2 rw INITRD ../initramfs-linux.img  LABEL archfallback LINUX ../vmlinuz-linux APPEND root=/dev/sda2 rw INITRD ../initramfs-linux-fallback.img

Create or edit $esp/EFI/syslinux/syslinux.cfg by following #Configuration. Note: The config file for UEFI is $esp/EFI/syslinux/syslinux.cfg, not /boot/syslinux/syslinux.cfg. Files in /boot/syslinux/ are BIOS specific and not related to UEFI Syslinux. Note: When booted in BIOS mode, efibootmgr will not be able to set EFI nvram entry for /efi/syslinux/syslinux.efi. To work around, place resources at the default EFI location: $esp/efi/syslinux/* -> $esp/efi/boot/* and $esp/efi/syslinux/syslinux.efi -> $esp/efi/boot/bootx64.efi

关注起来，syslinux搞定efi比grub2强大。