Tiny Core Extensions > TCE Tips & Tricks

Howto make a legacy bios/uefi dual boot usb stick with grub2

<< < (11/11)

patrikg:
When posting code of something like grub config, you can test to use the code button "#".

GNUser:
Juanito's excellent instructions (first post of this thread) are the best I could find anywhere on the internet detailing how to set up a usb stick that can boot in both BIOS and UEFI machines. Thank you, Juanito!

I just did two things differently.

1. I used gdisk instead of fdisk
UEFI requires a GPT partition table. fdisk does support GPT, so I don't think it matters much whether you use gdisk or fdisk. With gdisk, I discovered that I didn't have to specifically request a GPT partition table--it automatically uses GPT when creating partitions. Note that if you use gdisk to add partitions to a disk that already has an existing MBR table, the MBR table gets converted to a GPT table (gdisk warns you about this). Fortunately, in my experience using gdisk on multiple disks, this happens without any loss of partitions or data. (You should backup your data before doing this, of course, just to be safe.)

2. I put a BIOS boot partition on the disk:

--- Code: ---$ sudo gdisk /dev/sdc
...
Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048        52430847   25.0 GiB    8300  Linux filesystem
   2        52430848        52432895   1024.0 KiB  EF02  BIOS boot partition
   3        52432896        53481471   512.0 MiB   EF00  EFI system partition
--- End code ---

The BIOS boot partition only needs to be 1MiB in size and you do not need to format it or put anything in it. It just needs to be present, otherwise this step from Juanito's instructions results in an error (something about grub-install having no reliable way to install the target):


--- Code: ---$ sudo grub-install --target=i386-pc --boot-directory=/mnt/sdc3/EFI/BOOT /dev/sdc

--- End code ---

So in this partitioning scheme:
* TCL directories (/boot and /tce) go in /dev/sdc1 (same place as in Juanito's instructions)
* You don't have to do anything with /dev/sdc2 other than create it--grub-install takes care of the rest
* The only file you need to manually create in /dev/sdc3 is /dev/sdc3/EFI/BOOT/grub/grub.cfg

Navigation

[0] Message Index

[*] Previous page