From 2665fd009898b59f0c367715609936d43a262b30 Mon Sep 17 00:00:00 2001
From: cfig <yuyezhong@gmail.com>
Date: Wed, 30 Sep 2020 12:01:42 +0800
Subject: [PATCH] doc: misc and BootControl

---
 doc/hidl_boot_control.puml |  63 ++++++++++++++++++++++
 doc/misc_image_layout.md   | 108 +++++++++++++++++++++++++++++++------
 2 files changed, 154 insertions(+), 17 deletions(-)
 create mode 100644 doc/hidl_boot_control.puml

diff --git a/doc/hidl_boot_control.puml b/doc/hidl_boot_control.puml
new file mode 100644
index 0000000..d32e511
--- /dev/null
+++ b/doc/hidl_boot_control.puml
@@ -0,0 +1,63 @@
+@startuml
+
+package services {
+    class android_hardware_boot_1_1_service {
+        *cc_binary
+    }
+    class android_hardware_boot_1_0_service {
+        *cc_binary
+    }
+}
+
+
+package impls {
+    class android_hardware_boot_1_0_impl {
+        *cc_library
+    }
+
+    class android_hardware_boot_1_1_impl {
+        *cc_library
+    }
+}
+
+
+package hidl_interface {
+    class android_hardware_boot_1_0 {
+        *hidl_interface
+    }
+
+    class android_hardware_boot_1_1 {
+        *hidl_interface
+    }
+}
+
+
+android_hardware_boot_1_0_impl --> android_hardware_boot_1_0
+
+android_hardware_boot_1_0_service --> android_hardware_boot_1_0
+
+
+
+android_hardware_boot_1_1_impl --> android_hardware_boot_1_0
+android_hardware_boot_1_1_impl --> android_hardware_boot_1_1
+android_hardware_boot_1_1_impl --> libboot_control
+android_hardware_boot_1_1_impl ..> libboot_control_defaults
+
+
+android_hardware_boot_1_1_service --> android_hardware_boot_1_0
+android_hardware_boot_1_1_service --> android_hardware_boot_1_1
+class libboot_control_defaults {
+    *cc_defaults
+}
+libboot_control_defaults --> android_hardware_boot_1_1
+libboot_control_defaults --> libbootloader_message_vendor
+class libboot_control {
+    *cc_library_static
+}
+libboot_control ..> libboot_control_defaults
+class bootctrl_default {
+    *cc_library
+}
+bootctrl_default --> libboot_control
+bootctrl_default ..> libboot_control_defaults
+@enduml
diff --git a/doc/misc_image_layout.md b/doc/misc_image_layout.md
index 7567bc1..13197f8 100644
--- a/doc/misc_image_layout.md
+++ b/doc/misc_image_layout.md
@@ -1,20 +1,94 @@
 # /misc partition layout
 
-| - | - | - | size |  description |
-| :---- | :------ | :---- | :---- | :---- |
-| bootloader_message_ab |  |   | 4096 | |
-|   | bootloader_message |   | 2048 |   | 
-| | |command | 32 |updated by linux/bootloader |
-| | |status | 32 |deprecated |
-| | |recovery |768 |talking channel between normal/recovery modes |
-| | |stage | 32 |format "#/#", eg, "1/3" |
-| | |reserved | 1184| |
-| |slot_suffix | | 32| |
-| |update_channel | |128 | |
-| |reserved | | 1888| |
-| | | | | |
-| vendor bootloader msg | | | 12 KB | offset 4kB |
-| wipe_package info | | | 48K | offset 16KB, Used by uncrypt and recovery to store wipe_package for A/B devices |
-|- |- |- |- |- |
-| | | | | |
+| - | - | - | Offset | Size |  description |
+| :---- | :------ | :---- | :---- | :---- | ----- |
+| Legacy      | bootloader_message |   | 0 | (2K) |   |
+| | |command |  | 32 |updated by linux/bootloader |
+| | |status |  | 32 |deprecated |
+| | |recovery | |768 |talking channel between normal/recovery modes |
+| |                                              |stage |  | 32 |format "#/#", eg, "1/3" |
+| | |reserved | | 1184| |
+| - | - |- | - | - | - |
+| Vendor Area | vendor bootloader msg | N/A | 2K | 2K | Vendor Area                                                  |
+|             | vendor bootloader msg | N/A | 4K | 12K | pure Vendor area                                             |
+| -           | - | - | - | - | - |
+| Wipe        | wipe_package info                            | | 16K | 16K | offset 16KB, Used by uncrypt and recovery to store wipe_package for A/B devices |
+| -           | -                                            | - | - | - | - |
+| System      | system_space -> 1<br>misc_virtual_ab_message | |  | (64) | |
+| |  | version |  | 1 | |
+| |  | magic |  | 4 | |
+| |  | merge_status |  | 1 | |
+| |  | source_slot |  | 1 | |
+| |  | reserved |  | 57 | |
+| |  |  | | | |
+| |  |  | |  | |
+
+
+
+### vendor area implementation example from Google: 
+
+
+#### bootctrl.default.so (link libboot_control.a)貌似没人用
+
+
+使用legacy_boot_control.cpp, 把libboot_control.a的实现的类android::bootable::BootControl包装进去
+
+
+
+### android.hardware.boot@1.1-impl
+
+使用BootControl.cpp
+
+```
+android::hardware::boot::V1_1::implementation::BootControl
+```
+直接使用"android::bootable::BootControl"的实现
+
+
+
+
+
+
+
+
+#### libboot_control.a
+
+code location:
+
+```hardware/interfaces/boot/1.1/default/boot_control```
+
+https://android.googlesource.com/platform/hardware/interfaces/+/refs/heads/master/boot/1.1/default/boot_control/
+
+| - | - | - | Offset | Size |  description |
+| :---- | :------ | :---- | :---- | :---- | ----- |
+| Vendor Area | bootloader_message_ab | | 2K | (2K) | Vendor Area                                                  |
+| |                                              | slot_suffix | | 32| |
+| |                                              | update_channel | |128 | |
+| | | reserved | | 1888| |
+
+
+
+### 32 BYTES "slot_suffix" part details:
+
+| - | - | - | Offset | Size |  description |
+| :---- | :------ | :---- | :---- | :---- | ----- |
+| | bootloader_control |  | | (32) | |
+| |  | slot_suffix | | 4 | |
+| |  | magic | | 4 | |
+| |  | version | | 1 | |
+| |  | nb_slot | | 3bits | number slots |
+| |  | recovery_tries_remaining | | 3bits | |
+| |  | merge_status | | 3bits | |
+| |  | reserved0 | | 1 | |
+| |  | slot_info | | 8 | slot_metadata * 4 |
+| |  | reverved1 | | 8 | |
+| |  | crc32_le | | 4 | |
+| |  |  | |  | |
+| | slot_metadata | | | (2) | |
+| | | priority |  | 4bits | |
+| | | tries_remaining |  | 3bits | |
+| | | successful_boot | | 1bit | |
+| | | verity_corrupted | | 1bit | |
+| | | reserved | | 7bits | |
+| | | | |  | |