minimal files

[Pascal]

hi help-grub members,

my goal is to reduce Grub's size to its strict minimum.
so, what are, at a minimum, the files to copy/install in the /grub/ folder
to boot a kernel present in the /boot/ folder ?
these two folders are located on the same FAT32-formatted partition (ESP)
of a GPT disk.
this disk embeds a living system and is therefore likely to encounter a
wide variety of EFI-only PCs.

my old installation (with Grub 2.02) below was functional (with a few rare
exceptions) but is not anymore since the update of Grub (Grub 2.04) :

grub/
├── fonts
│   └── font.pf2
├── grub.cfg
└── x86_64-efi
    ├── boot.mod
    ├── bufio.mod
    ├── command.lst
    ├── core.efi
    ├── crypto.lst
    ├── crypto.mod
    ├── efi_gop.mod
    ├── efi_uga.mod
    ├── extcmd.mod
    ├── font.mod
    ├── fs.lst
    ├── gettext.mod
    ├── gfxterm.mod
    ├── grub.efi
    ├── linux.mod
    ├── minicmd.mod
    ├── mmap.mod
    ├── moddep.lst
    ├── modinfo.sh
    ├── normal.mod
    ├── partmap.lst
    ├── parttool.lst
    ├── relocator.mod
    ├── terminal.lst
    ├── terminal.mod
    ├── true.mod
    ├── video.lst
    ├── video.mod
    └── video_fb.mod

(ps. if for some modules their name speaks for itself, for others it is
less clear : a bit like for the kernel modules (eg. modinfo), where can we
find this information ?)

regards, lacsaP.