xubuntu 20.04 command efibootmgr -v has three columns after the BootOrder: line. The third column has either a boot loader entry or "RC" for CD or USB media. My HP laptop has W10 preinstalled with a recovery partition for W10, and of course I have Linux installed on another partition. The third column starts with "HD(foo)" for the W10 boot or Ubuntu boot, and it starts with "BBS HD(foo)" for the W10 recovery partition.
I searched the Internet, perused the 2700+ pages of the UEFI Spec and found that BBS may mean BIOS Boot Specification. But could not find out anything about the "RC" entry in the third column.
Just curious.
Actual output of the command as requested by a comment below
BootCurrent: 0001
Timeout: 5 seconds
BootOrder: 2002,2001,0001,0000,0008,2004
Boot0000* Windows Boot Manager HD(1,GPT,222a7e4f-cb9d-449e-b222-86fbc93595d8,0x800,0x82000)/File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...5................
Boot0001* ubuntu HD(1,GPT,222a7e4f-cb9d-449e-b222-86fbc93595d8,0x800,0x82000)/File(\EFI\ubuntu\shimx64.efi)
Boot0005* Internal Hard Disk or Solid State Disk RC
Boot0007* Internal Hard Disk or Solid State Disk RC
Boot0008* Notebook Hard Drive - ST1000LM035-1RK172 BBS(HD,Notebook Hard Drive - ST1000LM035-1RK172,0x500)................-...........A....................................X..|.......A.........................
Boot2001* EFI USB Device RC
Boot2002* EFI DVD/CDROM RC
Boot3001* Internal Hard Disk or Solid State Disk RC
This is an hp-15bs062st laptop, W10 preinstalled then messed up and reinstalled from hp-Microsoft OS stick.
Boot 0001 is my Ubuntu
Boot 0005, 0007 and 3001 are hard disk partitions used for linux swap and other mounted files
Boot 0000 and 0008 are Windows OS and Recovery
I don't know and don't really care what 2004 is in the boot order
Boot order is fine as is: machine boots into my Ubuntu, but if I have a bootable USB or CD it boots that not Ubuntu.
If I need W10 I can chose it at boot.
Everything makes sense except RC and why the Windows recovery is marked with BBS - but that's OK. My question was about the RC.
