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| -rw-r--r-- | README.md | 20 |
1 files changed, 19 insertions, 1 deletions
@@ -7,11 +7,13 @@ This document describes known methods of flashing BIOS on xx20 and xx30 series o - [Requirements](#requirements) - [BIOS versions](#bios-versions) - [Downgrading BIOS](#downgrading-bios) + - [Creating a backup](#creating-a-backup) - [Examining and removing protections](#examining-and-removing-protections) - [Theory](#theory) - [Practice](#practice) - [SandyBridge series (X220, T420, etc.): WIP](#sandybridge-series-x220-t420-etc-wip) - [Troubleshooting](#troubleshooting) + - [Flashing the backup back](#flashing-the-backup-back) - [Credits](#credits) # IvyBridge series (X230, T430, etc.) @@ -39,7 +41,7 @@ Below is a list of BIOS versions that are vulnerable enough for our goals, per m **T530**: 2.60<br> **W530**: 2.58 -If your BIOS version is equal or lower, skip to the **[Examining and removing protections](#examining-and-removing-protections)** section. If not, go through the downgrade process, described next. +If your BIOS version is equal or lower, skip to the **[Creating a backup](#creating-a-backup)** section. If not, go through the downgrade process, described next. ## Downgrading BIOS @@ -109,6 +111,15 @@ Boot from the USB drive (press F12 to select boot device), and BIOS flashing pro It may reboot a couple of times in the process. Do not interrupt it. +## Creating a backup + +You should create a backup of the `bios` region. Then, in case something goes wrong, you'll be able to just flash it back externally. + +The `me` region is locked, so an attempt to create a full backup will end with a `Transaction error!`. But you still can back up the `bios`: +``` +sudo flashrom -p internal -r bios_backup.rom --ifd -i bios +``` + ## Examining and removing protections ### Preparations @@ -321,6 +332,13 @@ Currenly there are no known methods to unlock PRs on these devices internally, b # Troubleshooting If something doesn't work, please let me know by creating an issue, or ask me on #coreboot. +## Flashing the backup back +If you have created a backup and need to flash it back, do this: +``` +sudo flashrom -p <YOUR_PROGRAMMER> -w bios_backup.rom --ifd -i bios +``` +**Caution:** DO NOT flash the whole backup, because it has `FF`s instead of `fd` and `me` and it will brick your device. Use `--ifd -i bios`. + # Credits **Rafal Wojtczuk** and **Corey Kallenberg** for discovering the vulnerability |