efi

Documentation

Overview

Package efi supports reading EFI variables.

Index

• Variables
• func MockVars(vars map[string][]byte, attrs map[string]VariableAttr) (restore func())
• type VariableAttr
  • func ReadVarBytes(name string) ([]byte, VariableAttr, error)
  • func ReadVarString(name string) (string, VariableAttr, error)

Variables

var ErrNoEFISystem = errors.New("not a supported EFI system")

Functions

func MockVars

func MockVars(vars map[string][]byte, attrs map[string]VariableAttr) (restore func())

MockVars mocks EFI variables as read by ReadVar*, only to be used from tests. Set vars to nil to mock a non-EFI system.

Types

type VariableAttr

type VariableAttr uint32

const (
	VariableNonVolatile       VariableAttr = 0x00000001
	VariableBootServiceAccess VariableAttr = 0x00000002
	VariableRuntimeAccess     VariableAttr = 0x00000004
)

see https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/include/linux/efi.h?h=v5.4.32

func ReadVarBytes

func ReadVarBytes(name string) ([]byte, VariableAttr, error)

ReadVarBytes will attempt to read the bytes of the value of the specified EFI variable, specified by its full name composed of the variable name and vendor ID. It also returns the attribute value attached to it. It expects to use the efivars filesystem at /sys/firmware/efi/efivars. https://www.kernel.org/doc/Documentation/filesystems/efivarfs.txt for more details.

func ReadVarString

func ReadVarString(name string) (string, VariableAttr, error)

ReadVarString will attempt to read the string value of the specified EFI variable, specified by its full name composed of the variable name and vendor ID. The string value is expected to be encoded as UTF16. It also returns the attribute value attached to it. It expects to use the efivars filesystem at /sys/firmware/efi/efivars. https://www.kernel.org/doc/Documentation/filesystems/efivarfs.txt for more details.