From 6d89f2729ab7a6ee3dd78ccaef1b16677b5a9eee Mon Sep 17 00:00:00 2001
From: kingofpayne <43875454+kingofpayne@users.noreply.github.com>
Date: Mon, 16 Sep 2024 22:07:56 +0200
Subject: boot: flash-erase-zero (#3344)

Allow compatibility with devices whose flash erase set bytes to 0x00
instead of 0xFF, using a new flash-erase-zero feature.
See issue #3342.
---
 docs/pages/bootloader.adoc | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'docs/pages/bootloader.adoc')

diff --git a/docs/pages/bootloader.adoc b/docs/pages/bootloader.adoc
index 3b0cdb182..d8d50040b 100644
--- a/docs/pages/bootloader.adoc
+++ b/docs/pages/bootloader.adoc
@@ -19,6 +19,8 @@ The bootloader supports
 
 In general, the bootloader works on any platform that implements the `embedded-storage` traits for its internal flash, but may require custom initialization code to work.
 
+STM32L0x1 devices require the `flash-erase-zero` feature to be enabled.
+
 == Design
 
 image::bootloader_flash.png[Bootloader flash layout]
-- 
cgit 


From 05d453bfd81bce49d541b2eeee3a8788e5a5fd7e Mon Sep 17 00:00:00 2001
From: Olivier Hériveaux <olivier.heriveaux@ledger.fr>
Date: Mon, 23 Sep 2024 16:11:45 +0200
Subject: Fixed signature script in bootloader documentation

---
 docs/pages/bootloader.adoc | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

(limited to 'docs/pages/bootloader.adoc')

diff --git a/docs/pages/bootloader.adoc b/docs/pages/bootloader.adoc
index 3b0cdb182..a80e75c4c 100644
--- a/docs/pages/bootloader.adoc
+++ b/docs/pages/bootloader.adoc
@@ -86,8 +86,7 @@ Then, to sign your firmware given a declaration of `FIRMWARE_DIR` and a firmware
 
 [source, bash]
 ----
-shasum -a 512 -b $FIRMWARE_DIR/myfirmware > $SECRETS_DIR/message.txt
-cat $SECRETS_DIR/message.txt | dd ibs=128 count=1 | xxd -p -r > $SECRETS_DIR/message.txt
+shasum -a 512 -b $FIRMWARE_DIR/myfirmware | head -c128 | xxd -p -r > $SECRETS_DIR/message.txt
 signify -S -s $SECRETS_DIR/key.sec -m $SECRETS_DIR/message.txt -x $SECRETS_DIR/message.txt.sig
 cp $FIRMWARE_DIR/myfirmware $FIRMWARE_DIR/myfirmware+signed
 tail -n1 $SECRETS_DIR/message.txt.sig | base64 -d -i - | dd ibs=10 skip=1 >> $FIRMWARE_DIR/myfirmware+signed
-- 
cgit 


From 69abc42077e6de4453d422330a9a07407a36f218 Mon Sep 17 00:00:00 2001
From: 9names <60134748+9names@users.noreply.github.com>
Date: Sun, 1 Jun 2025 00:08:09 +1000
Subject: doc: add high-level embassy-boot a-b info

---
 docs/pages/bootloader.adoc | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'docs/pages/bootloader.adoc')

diff --git a/docs/pages/bootloader.adoc b/docs/pages/bootloader.adoc
index 53f85d995..b0f0331aa 100644
--- a/docs/pages/bootloader.adoc
+++ b/docs/pages/bootloader.adoc
@@ -2,6 +2,13 @@
 
 `embassy-boot` a lightweight bootloader supporting firmware application upgrades in a power-fail-safe way, with trial boots and rollbacks.
 
+The update method used is referred to as an A/B partition update scheme.
+
+With a general-purpose OS, A/B partition update is accomplished by directly booting either the A or B partition depending on the update state.
+To accomplish the same goal in a way that is portable across all microcontrollers, `embassy-boot` swaps data page by page (in both directions) between the DFU and the Active partition when a firmware update is triggered. +
+Because the original Active application is moved into the DFU partition during this update, the operation can be reversed if the update is interrupted or the new firmware does not flag that it booted successfully. +
+See the design section for more details on how this is implemented.
+
 The bootloader can be used either as a library or be flashed directly if you are happy with the default configuration and capabilities.
 
 By design, the bootloader does not provide any network capabilities. Networking capabilities for fetching new firmware can be provided by the user application, using the bootloader as a library for updating the firmware, or by using the bootloader as a library and adding this capability yourself.
-- 
cgit