[beeflet]

It boots directly into the kernel without a bootloader. You can specify built-in command line options when you're compiling the kernel.

To dual-boot, I boot from a removable USB drive on my keychain. When it's not plugged in, it boots windows instead.

[vladvasiliu]

This may or may not apply to your situation, but at least some motherboards have an integrated bootloader. You need to register the options with it (via efibootmgr for example). Then pressing a key (check your manual) presents you with the options.

This has worked with both Linux and Widows on all my machines: handbuilt 3rd gen intel with an asus MB, 6th gen with some msi, 10th gen with a cheap Gigabyte, and an assorted bunch of HP Elite desks and books with intel and AMD.

I understand there’s even a way for them to auto detect the options, but since this has been a set it forget it type thing, I never bothered to look into it.