pyefiboot 0.0.2

Python API to manage EFI Boot Entries

pyefiboot

Python Library to manage EFI Boot Entries

The aim of this library is to provide an API to the functionality of the efibootmgr (https://github.com/rhinstaller/efibootmgr) application. This provides a programmatic mechanism to read and update the EFI Boot Variables, allowing scripting of tasks to manage the EFI boot process.

[!NOTE] The initial release is a straightforward read-only solution, effectively mimicking the features of efibootmgr and efibootmgr -v calls.

Installation

When complete, should be:

pip install pyefiboot

Seek information elsewhere about installing in a virtual environment

This library currently has no dependencies

Usage

Most work can be done via the BootManager class which reads and provides access to all Boot related EFI variables

Reading current Boot Entries

import pyefiboot

bootmgr = pyefiboot.BootManager()

bootmgr.update_from_efi()

Printing to screen

To get output similar to efibootmgr:

bootmgr.display()

To get output similar to efibootmgr -v:

bootmgr.display(verbose=True)

Reading the BootCurrent, BootNext, BootTimeout and BootOrder EFI Variables

import pyefiboot

cur = pyefiboot.BootCurrent()

# Integer value of the current EFI Boot Entry
x: int = cur.value

# String representation of the current EFI Boot Entry, four character hex number
y: str = cur.hex_value

# BootNext and BootTimeout have similar functionality to BootCurrent

ord = pyefiboot.BootOrder()

# List of integers mapping the current programmed order of EFI Boot Entries
x: list[int] = ord.value

# String representation of the current EFI Boot Entry order, displayed as comma separated string of four character hex numbers
y: str = ord.hex_value

Creation of any of the above four classes will raise an exception if the nominated EFI variable does not exist

Reading an EFI Boot Entry variable

import pathlib
import pyefiboot

entry1 = pyefiboot.BootEntry(efivar_name='Boot0001')
entry2 = pyefiboot.BootEntry(efivar_fullpath=pathlib.Path('/sys/firmware/efi/efivars/Boot0002-8be4df61-93ca-11d2-aa0d-00e098032b8c'))

# Print string representation of boot entry to screen
print(entry1)

# Print verbose string representation of boot entry to screen
print(entry1.verbose_str())

# String representation of Boot Entry Index, four character hex number
x: str = entry2.entry_num

# If the Boot Entry refers to an actual local kernel to boot, returns the string representing the kernel file name, otherwise None
y: str | None = entry2.kernel_file

Access to other variables within the BootEntry will be in future versions

Public Class Properties and APIs

BootTimeout

Upon creation will read the current value of the UEFI Timeout variable. If the variable does not exist, it will be stored as None

Properties

Property Name	Type	Action	Description
value	int or None	Read	Return timeout in seconds as an integer Return None if variable does not exist
value	int or None	Write	Set the timeout to the provided value Delete the UEFI Timeout variable if set to None
hex_value	string	Read	Return the current UEFI Timeout variable as a four-digit hex string
__str__	—	—	Class can be converted to string representation in format "BootTimeout: x seconds"

BootCurrent

Upon creation will read the current value of the UEFI BootCurrent variable

Properties

Property Name	Type	Action	Description
value	int	Read Only	Return the current UEFI BootCurrent variable as an integer
hex_value	string	Read	Return the current UEFI BootCurrent variable as a four-digit hex string
__str__	—	—	Class can be converted to string representation in format "BootCurrent: xxxx"

BootNext

Upon creation will read the current value of the UEFI BootNext variable. If the variable does not exist, it will be stored as None

Properties

Property Name	Type	Action	Description
value	int or None	Read	Return the Boot Entry index to be used on next boot as an integer Return None if variable does not exist
value	int or None	Write	Set the BootNext variable to the provided value Delete the UEFI BootNext variable if set to None
hex_value	string	Read	Return the current UEFI BootNext variable as a four-digit hex string
__str__	—	—	Class can be converted to string representation in format "BootNext: xxxx" or "BootNext "

BootOrder

Upon creation will read the current value of the UEFI BootOrder variable. If the variable does not exist, it will be stored as None

Properties

Property Name	Type	Action	Description
value	list[int] or None	Read	Return list of Boot Entry indexes as integers Return None if variable does not exist
value	list[int] or list[str] or None	Write	Set the Boot Order to the provided list of integers OR hex strings Delete the UEFI BootOrder variable if set to None
hex_value	string	Read	Return the current UEFI BootOrder as a comma separated list of hex boot entry values
__str__	—	—	Class can be converted to string representation in format "BootOrder: xxxx,yyyy,zzzz"

Logging

All modules within pyefiboot support Python logging, enabling logging and an appropriate log level in your application will allow these logs to be captured