I have a Lenovo T450 with a locked BIOS that only allows booting from HD or PXE.
I have installed Ubuntu using PXE but I would like to add an entry in GRUB to boot from a USB just in case there is an issue in future.
If I go into the BIOS the following relevant settings are:
- UEFI Secure Boot = Off
- Config - USB UEFI BIOS Support = Enabled
- Security - I/O Port Access - USB Port = Enabled
- Security - Secure Boot = Disabled
The only thing that looks to be blocking the USB is the fact that it is excluded from the boot order choices and I can't add it back.
The BIOS diagnostic text on boot lists the USB drive by name so it is recognized.
I looked at this question on manually adding an entry to grub
However, grub>ls only shows my hard disk and not my USB drive.
Although, when I boot into Ubuntu I can read the drive and see the UUID with blkid.
I installed Plop Boot Manager and added entries to /etc/grub.d/40_custom
menuentry "Plop Boot Manager 5" {
linux16 /boot/plop/plpbt.bin
}
menuentry "Plop Boot Manager 6" {
linux16 /boot/plop/pbm6
}
However, neither of these work. v5 errors with
Loading EHCI Driver
Searching on Hosts
Host 1
Port 1: Device Connected
No HD
Driver Removed
Loading UHCI Driver
Searching on Hosts
Driver Removed
Loading OHCI Driver
Searching on Hosts
Driver Removed
BOOT ERROR
NO BOOT DEVICE FOUND, PLEASE RETRY IT
Changing the setup to Force USB 1.1 to Mode 1 or Mode 2 doesn't fix it.
v6 says PBM6 - Init hardware..RegisterPartitions: Error then when it loads it only shows the SATA drive and not the USB drive in the menu.
What other options are there?
Since the USB is recognized in Ubuntu is it possible to add an extra partition with a kernel in it that loads the USB drivers then chains the boot to load from the USB?
