I am using an ASUS N53J that is currently using MBR boot. I have enabled UEFI booting in the bios can can seem to boot USB drives that have been configured with gpt tables. Though I have not figured out how to make use of a dedicated EFI boot partition on the USB drive as yet.
Separately I have connected a second hdd to the laptop via the external SATA connection, created a gpt partition table, esp boot partition, and the filesystem and swap partitions.
When I run
grub-mkconfig on the internal hdd, it finds the new linux image on the external hdd. I can boot to that external image and confirm that the esp boot partition gets mounted at
/boot/efi, so it appears that I should be able to configure grub2. However, if I run
grub-mkconfig when executing from the external drive, its own image does not get found, only the linux and windows images on the internal drive.
I also cannot get
efibootmgr to run. The tutorials I have read either are not clear on both the how and the why so I can troubleshoot myself or use commands that I cannot find in the packages I think they are using. Does anyone have a good pointer on how to configure the disk before I install it as the primary boot disk?
I have progressed to making a USB drive that will at least boot into grub rescue. I do not know why grub won't run from this drive but it at least allows me to manually boot to my target OS. Since I have now booted via a UEFI boot
efibootmgr is available.
I performed a new grub-install targeting the esp partition mounted at
/boot/efi. This completed without errors. However, when I select the target system for booting the firmware loader stops at a blank screen. This occurs whether the disk is connected via ESATA or has been moved to be the primary disk in the machine.
the output of
efibootmgr -v is:
BootCurrent: 0003 Timeout: 2 seconds BootOrder: 0005,0002,0003,0004,0000,0001 Boot0000 Hard Drive BBS(HD,,0x0) Boot0001 CD/DVD Drive BBS(CDROM,,0x0)P1: Slimtype BD E DS4E1S . Boot0002* ubuntu 15.10 HD(1,GPT,8b6800c2-0b24-4f00-aa66-b1378052604e,0x800,0xfa000)/File(\bootx64.efi) Boot0003* grub HD(2,GPT,b07e72fd-9168-4924-a17c-b75e55ed685c,0x800,0xfa000)/File(\Shellx64.efi) Boot0004* UEFI: SanDisk Cruzer Micro 1.26 PciRoot(0x0)/Pci(0x1d,0x0)/USB(1,0)/USB(2,0)/HD(2,GPT,b07e72fd-9168-4924-a17c-b75e55ed685c,0x800,0xfa000) Boot0005* ubuntu15.10 HD(1,GPT,8b6800c2-0b24-4f00-aa66-b1378052604e,0x800,0xfa000)/File(\EFI\ubuntu15.10\grubx64.efi)
The desired target is
Boot0002 is an experiment copying
Boot0005 behave similarly.
Boot0003 (grub) is the USB drive and the only means to boot, though it only starts in grub rescue.
Any ideas where I should explore or what additional information may assist diagnosis?
grub rescue> set prefix=(hd0,2)/boot/grub ... This is the fat32-formatted esp boot partition grub rescue>ls (hd0,2)/ unknown filesystem ... or similar words to that effect grub rescue>set prefix=(hd0,1)/boot/grub ... ext4-formatted partition grub rescue> insmod fat grub rescue>ls (hd0,2)/ .... the directory is now read
setting the root to the target boot system and the prefix to the /boot/grub directory of that target system I can
insmod linux search config file and normal. If normal does not start the boot option page the following will:
grub rescue>configfile /boot/grub/grub.cfg
I can eventually get the target to boot from the menu.
My synopsis is that
grubx64.efi on the USB drive is not configured with the necessary modules for the boot method being used.
While efi-booted into my target filesystem I created a new USB drive, also with a gpt partition table, this time with esp boot as partition 1. I only mention that to assist with reading the bios boot table presented later.
mounting USB partition 2 to an appropriate node:
mkdir -p /boot/efi
mount (USB partition 1) to (USB partition 2)/boot/efi
grub-install --target=x86_64-efi --efi-directory=(USB partition 2)/boot/efi --removable
EFI/BOOT/BOOTx64.EFI. The UEFI: Sandisk entry in the bios boot table is the means to boot via this loader
grub-install --target=x86_64-efi --efi-directory=(USB partition2)/boot/efi --bootloader-id=USBboot
EFI/USBboot/grubx64.efi. The USBboot entry is also written int the bios boot table
cmp -v BOOT/BOOTx64.EFI USBboot/grubx64.efi yields no differences
either boot option now boots directly to the target filesystem without displaying any grub boot menu. Since the USB drive does not have a
/boot/grub directory or a
grubx64.exe must be configured to search for this directory on the target rather than USB.
$ efibootmgr -v BootOrder: 0007,0004,0005,0002,0003,0008,0000,0001 Boot0000 Hard Drive BBS(HD,,0x0) Boot0001 CD/DVD Drive BBS(CDROM,,0x0)P1: Slimtype BD E DS4E1S . Boot0002* ubuntu 15.10 HD(1,GPT,8b6800c2-0b24-4f00-aa66-b1378052604e,0x800,0xfa000)/File(\bootx64.efi) Boot0003* grub HD(2,GPT,b07e72fd-9168-4924-a17c-b75e55ed685c,0x800,0xfa000)/File(\Shellx64.efi) Boot0004* ubuntu_15_10 HD(1,GPT,8b6800c2-0b24-4f00-aa66-b1378052604e,0x800,0xfa000)/File(\EFI\ubuntu_15_10\grubx64.efi) Boot0005* ubuntu15.10 HD(1,GPT,8b6800c2-0b24-4f00-aa66-b1378052604e,0x800,0xfa000)/File(\EFI\ubuntu15.10\grubx64.efi) Boot0007* USBboot HD(1,GPT,f887bf87-18a9-40e1-9bca-6c4bfd1cbb4a,0x800,0xc8000)/File(\EFI\USBboot\grubx64.efi) Boot0008* UEFI: SanDisk PciRoot(0x0)/Pci(0x1d,0x0)/USB(1,0)/USB(4,0)/HD(1,GPT,f887bf87-18a9-40e1-9bca-6c4bfd1cbb4a,0x800,0xc8000)
I still have not figured out how to even get to grub rescue without booting from the external USB drive. Is seems as though I have two problems:
- I don't fully understand how to configure grub for its intended use, how to make sure necessary modules are built in and the prefix is properly set.
- I either do not have the bios on the ASUS N53J properly configured or it is not accepting the hard disk configuration as a valid boot configuration.
Any other ideas? I now this is getting rather long. How can I document this to be more readable?
Browsing on the web I have discovered
grub-mkimage. I have not started working with this and will report progress once I have done so and can either understand the results or can pose a new question about it.