`EFI_NOT_FOUND` for `btrfs(<...>)` syntax. (some debug info provided).

[Esgariot]

Hi, I'm trying to boot from btrfs subvolume and I'm getting Unable to parse ARC name, along with EFI_NOT_FOUND error code.

my loader entry looks like this:

[Windows]
SystemPath=btrfs(b6abd326-f396-4479-99d2-4a5ca63c7da6)\Windows
Options=/SUBVOL=@win

and here's btrfs check and btrfs subvolume list that match stuff provided above:

• subvolume: ID 272 gen 1173 top level 5 path @win
• uuid: UUID: b6abd326-f396-4479-99d2-4a5ca63c7da6

Additionally, I've built top of master, and added some debug prints here and there, and it goes like this:

1. this is the part that fails in boot.c, with Status being EFI_NOT_FOUND

       // Inside parse_arc_name
       EFI_GUID quibble_guid = EFI_QUIBBLE_PROTOCOL_GUID;
       EFI_HANDLE* handles = NULL;
       UINTN count;
   
       Status = bs->LocateHandleBuffer(ByProtocol, &quibble_guid, NULL, &count, &handles);
       if (EFI_ERROR(Status)) {
           print_string("Unable to parse ARC name, because of EFI_ERROR.\n");
           print_error("Error:", Status);
           return Status;
       }

2. After printing calls of almost every function in btrfs.c I get thousands of calls to drv_supported and couple of calls to drv_start, then the TUI with entry selection comes up, after selecting Windows I get

           Unable to parse ARC name, because of EFI_ERROR.
           Error: EFI_NOT_FOUND

[Esgariot]

There's also Loading driver btrfs.efi... success

[maharmstone]

The /SUBVOL option is supposed to be the subvol's number, in hex: so it should be Options=/SUBVOL=110. Does that fix things?

[Esgariot]

Sadly, nope. I don't think it gets to the parsing of Options part, without it, using root subvolume it produces the same error, and when using multipart(0)... syntax it also failed on EFI_NOT_FOUND after making some progress, but that's another problem I might encounter after resolving this one.

[Esgariot]

Hmm, maybe there's a problem with multiple btrfs drivers being loaded? Because other than quibble's, I'm using refind with btrfs_x64.efi from https://efi.akeo.ie