diff options
| author | Paarth Shirsat <paarthshirsat123@gmail.com> | 2026-04-25 15:10:27 +0000 |
|---|---|---|
| committer | Benedict Reuschling <bcr@FreeBSD.org> | 2026-04-25 15:12:04 +0000 |
| commit | 4137c673fa963fdf409eba2f48d615350c988ffe (patch) | |
| tree | fa19835c9da17cb858ad24551a4a8f73f393cdbd | |
| parent | ed82c433efee1080fc5587325754afd6fcabd5d6 (diff) | |
loader.efi(8): Document LoaderEnv and NextLoaderEnv EFI variables
Describe how the LoaderEnv and NextLoaderEnv variables can be used.
PR: 293054
Reviewed by: imp
Sponsored by: Wiesbaden Hackathon 202604
Differential Revision: https://reviews.freebsd.org/D56633
| -rw-r--r-- | stand/man/loader.efi.8 | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/stand/man/loader.efi.8 b/stand/man/loader.efi.8 index 8bb88dd2e24f..32729ff519a2 100644 --- a/stand/man/loader.efi.8 +++ b/stand/man/loader.efi.8 @@ -217,14 +217,47 @@ functionality where we use the video console if a keyboard is connected and a serial console otherwise. .Ss Additional Environment Variables .Nm -loads some extra variables early in startup from -.Pa /efi/freebsd/loader.env -from the EFI partition. -Only simple variables can be set here. +can set variables early in startup from a file on the EFI partition. +By default, that file is +.Pa /efi/freebsd/loader.env . +It can be changed by setting the FreeBSD EFI variable +.Va LoaderEnv , +as in: +.Bd -literal -offset indent +echo -n /efi/freebsd/alt.env | efivar -w -t 7 \\ + -n cfee69ad-a0de-47a9-93a8-f63106f8ae99-LoaderEnv +.Ed +.Pp +After that is executed, the file +.Pa /efi/freebsd/alt.env +is used instead of +.Pa /efi/freebsd/loader.env . +See +.Xr efivar 8 +for more information on setting EFI variables. +.Pp +The EFI variable +.Va NextLoaderEnv +can be set to the pathname of a second startup file. +That variable is deleted immediately after its value is retrieved, +so setting it will affect only the next boot attempt. +For either variable, a missing file is silently ignored. +.Pp +Only simple variables can be set in the startup file. It can be useful to specify the root filesystem: .Bd -literal -offset indent rootdev=disk0s1a .Ed +.Pp +The startup file contains a series of assignments separated by spaces, +tabs, or newlines. +Quotes are not given any special treatment. +If no +.Li =value +is given, the value +.Li 1 +is used. +Invalid syntax and the like are silently ignored. .Ss Staging Slop The kernel must parse the firmware memory map tables to know what memory it can use. |