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authorAlyssa Rosenzweig <alyssa@rosenzweig.io>2017-03-17 23:15:09 -0700
committerAlyssa Rosenzweig <alyssa@rosenzweig.io>2017-03-17 23:15:09 -0700
commit1eb5130a1c70a7238548d977e9c6f371c007eed7 (patch)
treeee28aa07cbb52f25b5f468f59ec8d9587edff739 /docs/depthcharge
parentb62dbec1e23f03ae944b51fc4b510dc56ed9b83e (diff)
downloadlibrebootfr-1eb5130a1c70a7238548d977e9c6f371c007eed7.tar.gz
librebootfr-1eb5130a1c70a7238548d977e9c6f371c007eed7.zip
It wasn't me, I swear!
Diffstat (limited to 'docs/depthcharge')
-rw-r--r--docs/depthcharge/index.md63
1 files changed, 42 insertions, 21 deletions
diff --git a/docs/depthcharge/index.md b/docs/depthcharge/index.md
index d4f7f9f6..55445e61 100644
--- a/docs/depthcharge/index.md
+++ b/docs/depthcharge/index.md
@@ -42,7 +42,8 @@ Developer mode screen {#developer_mode_screen}
=====================
The developer mode screen can be accessed in depthcharge when developer
-mode is enabled.\
+mode is enabled.
+
Developer mode can be enabled from the [recovery mode
screen](#recovery_mode_screen).
@@ -65,7 +66,8 @@ Booting normally {#booting_normally}
----------------
As instructed on the developer mode screen, a regular boot will happen
-after **3 seconds** (if developer mode screen is not held).\
+after **3 seconds** (if developer mode screen is not held).
+
The default boot medium (internal storage, external media, legacy
payload) is shown on screen.
@@ -77,7 +79,8 @@ Booting from different mediums {#booting_different_mediums}
Depthcharge allows booting from different mediums, when they are allowed
(see [configuring verified boot
parameters](#configuring_verified_boot_parameters) to enable or disable
-boot mediums).\
+boot mediums).
+
As instructed on the developer mode screen, booting from various mediums
can be triggered by pressing various key combinations:
@@ -91,9 +94,11 @@ Showing device information {#showing_device_information}
--------------------------
As instructed on the developer mode screen, showing device information
-can be triggered by pressing **Ctrl + I** or **Tab**.\
+can be triggered by pressing **Ctrl + I** or **Tab**.
+
Various information is shown, including vboot non-volatile data, TPM
-status, GBB flags and key hashes.\
+status, GBB flags and key hashes.
+
@@ -125,19 +130,22 @@ Recovering from a bad state {#recovering_bad_state}
When the device fails to verify the signature of a piece of the boot
software or when an error occurs, it is considered to be in a bad state
-and will instruct the user to reboot to recovery mode.\
+and will instruct the user to reboot to recovery mode.
+
Recovery mode boots using only software located in write-protected
memory, that is considered to be trusted and safe.
Recovery mode then allows recovering the device by booting from a
trusted recovery media, that is automatically detected when recovery
mode starts. When no external media is found or when the recovery media
-is invalid, instructions are shown on screen.\
+is invalid, instructions are shown on screen.
+
Trusted recovery media are external media (USB drives, SD cards, etc)
that hold a kernel signed with the recovery key.
Google provides images of such recovery media for Chrome OS (which are
-not advised to users as they contain proprietary software).\
+not advised to users as they contain proprietary software).
+
They are signed with Google's recovery keys, that are pre-installed on
the device when it ships.
@@ -152,7 +160,8 @@ Enabling developer mode {#enabling_developer_mode}
-----------------------
As instructed on the recovery mode screen, developer mode can be enabled
-by pressing **Ctrl + D**.\
+by pressing **Ctrl + D**.
+
Instructions to confirm enabling developer mode are then shown on
screen.
@@ -164,7 +173,8 @@ Configuring verified boot parameters {#configuring_verified_boot_parameters}
Depthcharge's behavior relies on the verified boot (vboot) reference
implementation, that can be configured with parameters stored in the
-verified boot non-volatile storage.\
+verified boot non-volatile storage.
+
These parameters can be modified with the **crossystem** tool, that
requires sufficient privileges to access the verified boot non-volatile
storage.
@@ -174,7 +184,8 @@ boot non-volatile storage on some devices. **crossystem** and **mosys**
are both free software and their source code is made available by
Google:
[crossystem](https://chromium.googlesource.com/chromiumos/platform/vboot_reference/).
-[mosys](https://chromium.googlesource.com/chromiumos/platform/mosys/).\
+[mosys](https://chromium.googlesource.com/chromiumos/platform/mosys/).
+
These tools are not distributed along with Libreboot yet. However, they
are preinstalled on the device, with ChromeOS.
@@ -187,32 +198,42 @@ security of the device.
The following parameters can be configured:
- Kernels signature verification:
- - Enabled with:\
+ - Enabled with:
+
# **crossystem dev\_boot\_signed\_only=1**
- - Disabled with:\
+ - Disabled with:
+
# **crossystem dev\_boot\_signed\_only=0**
- External media boot:
- - Enabled with:\
+ - Enabled with:
+
# **crossystem dev\_boot\_usb=1**
- - Disabled with:\
+ - Disabled with:
+
# **crossystem dev\_boot\_usb=0**
- Legacy payload boot:
- - Enabled with:\
+ - Enabled with:
+
# **crossystem dev\_boot\_legacy=1**
- - Disabled with:\
+ - Disabled with:
+
# **crossystem dev\_boot\_legacy=0**
- Default boot medium:
- - Internal storage:\
+ - Internal storage:
+
# **crossystem dev\_default\_boot=disk**
- - External media:\
+ - External media:
+
# **crossystem dev\_default\_boot=usb**
- - Legacy payload:\
+ - Legacy payload:
+
# **crossystem dev\_default\_boot=legacy**
-Copyright © 2015 Paul Kocialkowski <contact@paulk.fr>\
+Copyright © 2015 Paul Kocialkowski <contact@paulk.fr>
+
Permission is granted to copy, distribute and/or modify this document
under the terms of the Creative Commons Attribution-ShareAlike 4.0
International license or any later version published by Creative