Thank you all, for the help until now. I didn't solve my problem yet, but I realised some troubles and mistakes that I've being made.
First I'll divide those problematic situations I've suffered: 1.I was using Genkernel to configure and build the kernel, but Genkernel’s menuconfig doesn’t work like make menuconfig. Genkernel replace my .config everytime I run genkernel –menuconfig all, with this, I my .config has lost XFS build-in, because default Genkernel .config has setted XFS as a module. 2. I’m using rEFInd, installed from Windows 10, I’ll need dual boot. Now I understand that rEFInd can substitute GRUB, but I’ve read a lots of wikis, and it became a little bit confusing. Based on wikis I’ve configured my kernel with EFI stub thinking that is necessary to boot with GRUB only because UEFI. 3. GRUB has booted my kernel, but this EFI Stub’s over-configured kernel, maybe has complicated the situation with GRUB. (I've only supposed that). Expose that, or I configure kernel to use GRUB or rEFInd. I’m leaned to use on rEFInd, but I suffered to create initramfs with gernkernel once, in fact I do not like genkernel at all.
