UEFI boot process, initramfs related
What are the valid locations for initramfs.img in RHEL-6.4 with UEFI supported hardware?
Are the locations for initramfs.img different for BIOS and UEFI systems?
Responses
Guru
6827 points
Hi Roseline Joseph,
The below link doesn't include the location for initrafms.. hopefully someone will chime in with that... I suspect there would be no difference for initrafms location, that it it is under /boot/ but can not immediately confirm.
Check out this documentation at Red Hat, apparently there is a difference for the grub file (not what you were asking).
-
Quoted from above:
"GRUB has the advantage of being able to read ext2, ext3, and ext4 [17] partitions and load its configuration file — /boot/grub/grub.conf (for BIOS) or /boot/efi/EFI/redhat/grub.conf (for UEFI) — at boot time." -
The URL has "https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Installation_Guide/s1-grub-configfile.html" with the "6" seeming to be across rhel 6 in general.
On some very rare occasions, I've found RHEL documentation in need of update, so if you find something else - let Red Hat know... (my first bugzilla was for the man page for iptables and the documetation at Red Hat covering it.)
Does anyone else know of anything different?
Regards,
Remmele
Guru
6863 points
I don't know this for certain, but I am fairly confident this is how it works...
/boot - ext3/4 - contains vmlinuz, initramfs, etc...
/boot/efi - vfat - contains all the "efi" files
If the BIOS is configured to boot UEFI, then it scans for the vfat partition and attempts to find relevant *.efi files. Which I believe then hands the process back to utilize the partition which will be mounted as /boot.
[root@cypher ~]# find /boot/efi/
/boot/efi/
/boot/efi/EFI
/boot/efi/EFI/redhat
/boot/efi/EFI/redhat/grub.conf
/boot/efi/EFI/redhat/grub.efi
[root@cypher ~]# ls /boot/
config-2.6.32-358.el6.x86_64 symvers-2.6.32-431.3.1.el6.x86_64.gz
config-2.6.32-431.3.1.el6.x86_64 symvers-2.6.32-431.5.1.el6.x86_64.gz
config-2.6.32-431.5.1.el6.x86_64 symvers-2.6.32-431.el6.x86_64.gz
config-2.6.32-431.el6.x86_64 System.map-2.6.32-358.el6.x86_64
efi System.map-2.6.32-431.3.1.el6.x86_64
grub System.map-2.6.32-431.5.1.el6.x86_64
initramfs-2.6.32-358.el6.x86_64.img System.map-2.6.32-431.el6.x86_64
initramfs-2.6.32-431.3.1.el6.x86_64.img vmlinuz-2.6.32-358.el6.x86_64
initramfs-2.6.32-431.5.1.el6.x86_64.img vmlinuz-2.6.32-431.3.1.el6.x86_64
initramfs-2.6.32-431.el6.x86_64.img vmlinuz-2.6.32-431.5.1.el6.x86_64
lost+found vmlinuz-2.6.32-431.el6.x86_64
symvers-2.6.32-358.el6.x86_64.gz
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