Code:
cp /boot/grub/stage1/stage1 /boot/grub
cp /boot/grub/stage2/stage2 /boot/grub
Apart from Linux I have installed Grub in Dos, BSD and data-only partitions (without an operating system). I can confirm Grub only looks for stage1 and stage2 in /boot/grub. The other place Grub will check is /boot.
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Directly from the Grub Manual
— Command: setup [--force-lba] [--stage2=os_stage2_file] [--prefix=dir] install_device [image_device]
Set up the installation of GRUB automatically. This command uses the more flexible command install (see install) in the backend and installs GRUB into the device install_device. If image_device is specified, then find the GRUB images (see Images) in the device image_device, otherwise use the current root device, which can be set by the command root. If install_device is a hard disk, then embed a Stage 1.5 in the disk if possible.
The option --prefix specifies the directory under which GRUB images are put. If it is not specified,
GRUB automatically searches them in /boot/grub and /grub.
The options --force-lba and --stage2 are just passed to install if specified. See install, for more information.