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Commit | Line | Data |
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e913ca7d MF |
1 | |
2 | efivarfs - a (U)EFI variable filesystem | |
3 | ||
4 | The efivarfs filesystem was created to address the shortcomings of | |
5 | using entries in sysfs to maintain EFI variables. The old sysfs EFI | |
6 | variables code only supported variables of up to 1024 bytes. This | |
7 | limitation existed in version 0.99 of the EFI specification, but was | |
8 | removed before any full releases. Since variables can now be larger | |
9 | than a single page, sysfs isn't the best interface for this. | |
10 | ||
11 | Variables can be created, deleted and modified with the efivarfs | |
12 | filesystem. | |
13 | ||
14 | efivarfs is typically mounted like this, | |
15 | ||
16 | mount -t efivarfs none /sys/firmware/efi/efivars | |
ed8b0de5 PJ |
17 | |
18 | Due to the presence of numerous firmware bugs where removing non-standard | |
19 | UEFI variables causes the system firmware to fail to POST, efivarfs | |
20 | files that are not well-known standardized variables are created | |
21 | as immutable files. This doesn't prevent removal - "chattr -i" will work - | |
22 | but it does prevent this kind of failure from being accomplished | |
23 | accidentally. |