grub: Chain-loading
5.1.2 Chain-loading an OS
-------------------------
Operating systems that do not support Multiboot and do not have specific
support in GRUB (specific support is available for Linux, FreeBSD,
NetBSD and OpenBSD) must be chain-loaded, which involves loading another
boot loader and jumping to it in real mode.
The 'chainloader' command (⇒chainloader) is used to set this
up. It is normally also necessary to load some GRUB modules and set the
appropriate root device. Putting this together, we get something like
this, for a Windows system on the first partition of the first hard
disk:
menuentry "Windows" {
insmod chain
insmod ntfs
set root=(hd0,1)
chainloader +1
}
On systems with multiple hard disks, an additional workaround may be
required. ⇒DOS/Windows.
Chain-loading is only supported on PC BIOS and EFI platforms.
Info Catalog
grub: Loading an operating system directly
grub: General boot methods