How does grub boot into initramfs ?

[ranshalit]

Hello,

Does anyone knows how kernels knows that it need first to start initramfs ?
I see the line in grub with:
initrd16 <initramfs file>

But I don't understand what actually makes kernel start init in ramfs.

Thanks,

[aks]

Grub does not "boot" into initrd, it's passed as an argument and contains the basic things needed (like the device driver to read from persistent storage). More info can be found in the System Administration guide on RHEL 7 docs.