## GRUB multiboot 

So, technically GRUB can load and ELF64 with some moments:

1) Multiboot requires special header.
2) Special calling convention - Multiboot passes boot info in EAX/EBX (magic + Multiboot info struct pointer).
3) Multiboot1 enters in 32-bit protected mode - Long mode is not set up. We need a 32->64 bit trampoline.
Multiboot2 has a 64-bit EFI handoff tag, but that's a different path.
4) Multiboot is x86-only
5) We haven't BootInfo, like i did in UEFI

Also Multiboot have stack. When UEFI jumps to kernel, no stack exists for the kernel. Because of it i use asm code to run kernel.
GRUB sets up a basic stack before jump. But, we don't know size and location of this stack.


Example of "kernel" that use it: https://github.com/igmunv/kosmos