Android OTA update: Compile the update package

Original article: http://blog.csdn.net/zjujoe/article/details/6206010

Android OTA update: Compile the update package

Author: Song Lixin

Email: zjujoe@yahoo.com

Preface

OTA update is a standard software upgrade method provided by the Android system. It is powerful and provides full upgrade and incremental upgrade modes. It can be upgraded through the SD card or through the network.

Here, we will first study the simplest situation and complete the upgrade through the SD card.

There is not much to say about how to perform the upgrade. There is a lot of information on the Internet. (For example, how to upgrade HTC mobile phones ). We are interested in how it is implemented and how developers modify it to meet our customization needs.

First, we will study the compilation process of the OTA update package.

Quick Start

Compile Android first, and then execute:

Make otapackage

You can get: Out/target/product/{product_name}/export product_name1_-ota-eng.w.uid=.zip.

Change the file name to update.zip and put it in the TKA root directory to start OTA update in recovery mode.

Compilation process research

 

There are two main steps. The first step is to prepare a package containing the content (raw materials) required for the upgrade, such as the system directory.

Step 2: run the Python script./build/tools/releasetools/ota_from_target_files. Use the zip package prepared in step 1 as the input to generate the required upgrade package.

 

Step 1

The compilation script is as follows:

(From: build/CORE/makefile)

 

 

1. 1073 # depending on the various images guarantees that the underlying
2. 1074 # directories are up-to-date.
3. 1075 $ (built_target_files_package ):/
4. 1076 $ (installed_bootimage_target )/
5. 1077 $ (installed_radioimage_target )/
6. 1078 $ (installed_recoveryimage_target )/
7. 1079 $ (installed_factoryimage_target )/
8. 1080 $ (installed_systemimage )/
9. 1081 $ (installed_userdataimage_target )/
10. 1082 $ (installed_secroimage_target )/
11. 1083 $ (installed_android_info_txt_target )/
12. 1084 $ (built_ota_tools )/
13. 1085 $ (apkcerts_file )/
14. 1086 $ (host_out_executables)/fs_config/
15. 1087 | $ (ACP)
16. 1088 @ echo "package target files: $ @"
17. 1089 $ (hide) Rm-RF $ @ $ (zip_root)
18. 1090 $ (hide) mkdir-p $ (DIR $ @) $ (zip_root)
19. 1091 @ # components of the recovery Image
20. 1092 $ (hide) mkdir-p $ (zip_root)/recovery
21. 1093 $ (hide) $ (call package_files-copy-root ,/
22. 1094 $ (target_recovery_root_out), $ (zip_root)/recovery/ramdisk)
23. 1095 ifdef installed_kernel_target
24. 1096 $ (hide) $ (ACP) $ (installed_kernel_target) $ (zip_root)/recovery/kernel
25. 1097 $ (hide) $ (ACP) $ (recovery_ramdisk) $ (zip_root)/recovery/ramdisk
26. 1098 endif
27. 1099 ifdef installed_2ndbootloader_target
28. 1100 $ (hide) $ (ACP )/
29. 1101 $ (installed_2ndbootloader_target) $ (zip_root)/recovery/second
30. 1102 endif
31. 1103 ifdef board_kernel_1_line
32. 1104 $ (hide) echo "$ (board_kernel_cmdline)" >$ (zip_root)/recovery/cmdline
33. 1105 endif
34. 1106 ifdef board_kernel_base
35. 1107 $ (hide) echo "$ (board_kernel_base)"> $ (zip_root)/recovery/base
36. 1108 endif
37. 1109 @ # components of the factory Image
38. 1110 $ (hide) mkdir-p $ (zip_root)/factory
39. 1111 $ (hide) $ (call package_files-copy-root ,/
40. 1112 $ (target_factory_root_out), $ (zip_root)/Factory/ramdisk)
41. 1113 ifdef installed_kernel_target
42. 1114 $ (hide) $ (ACP) $ (installed_kernel_target) $ (zip_root)/Factory/kernel
43. 1115 endif
44. 1116 ifdef installed_2ndbootloader_target
45. 1117 $ (hide) $ (ACP )/
46. 1118 $ (installed_2ndbootloader_target) $ (zip_root)/Factory/second
47. 1119 endif
48. 1120 ifdef board_kernel_1_line
49. 1121 $ (hide) echo "$ (board_kernel_cmdline)" >$ (zip_root)/Factory/export line
50. 1122 endif
51. 1123 ifdef board_kernel_base
52. 1124 $ (hide) echo "$ (board_kernel_base)"> $ (zip_root)/Factory/base
53. 1125 endif
54. 1126 @ # components of the Boot Image
55. 1127 $ (hide) mkdir-p $ (zip_root)/boot
56. 1128 $ (hide) $ (call package_files-copy-root ,/
57. 1129 $ (target_root_out), $ (zip_root)/boot/ramdisk)
58. 1130 ifdef installed_kernel_target
59. 1131 $ (hide) $ (ACP) $ (installed_kernel_target) $ (zip_root)/boot/kernel
60. 1132 $ (hide) $ (ACP) $ (installed_ramdisk_target) $ (zip_root)/boot/ramdisk
61. 1133 endif
62. 1134 ifdef installed_2ndbootloader_target
63. 1135 $ (hide) $ (ACP )/
64. 1136 $ (installed_2ndbootloader_target) $ (zip_root)/boot/second
65. 1137 endif
66. 1138 ifdef board_kernel_1_line
67. 1139 $ (hide) echo "$ (board_kernel_cmdline)" >$ (zip_root)/boot/cmdline
68. 1140 endif
69. 1141 ifdef board_kernel_base
70. 1142 $ (hide) echo "$ (board_kernel_base)"> $ (zip_root)/boot/base
71. 1143 endif
72. 1144 $ (hide) $ (foreach T, $ (installed_radioimage_target ),/
73. 1145 mkdir-p $ (zip_root)/Radio ;/
74. 1146 $ (ACP) $ (t) $ (zip_root)/Radio/$ (notdir $ (t ));)
75. 1147 @ # contents of the System Image
76. 1148 $ (hide) $ (call package_files-copy-root ,/
77. 1149 $ (systemimage_source_dir), $ (zip_root)/System)
78. 1150 @ # contents of the data image
79. 1151 $ (hide) $ (call package_files-copy-root ,/
80. 1152 $ (target_out_data), $ (zip_root)/data)
81. 1153 @ # extra contents of the OTA package
82. 1154 $ (hide) mkdir-p $ (zip_root)/OTA/bin
83. 1155 $ (hide) $ (ACP) $ (installed_android_info_txt_target) $ (zip_root)/OTA/
84. 1156 $ (hide) $ (ACP) $ (private_ota_tools) $ (zip_root)/OTA/bin/
85. 1157 @ # files that do not end up in any images, but are necessary
86. 1158 @ # build them.
87. 1159 $ (hide) mkdir-p $ (zip_root)/meta
88. 1160 $ (hide) $ (ACP) $ (apkcerts_file) $ (zip_root)/META/apkcerts.txt
89. 1161 $ (hide) echo "$ (product_ota_public_keys)" >$ (zip_root)/META/otakeys.txt
90. 1162 $ (hide) echo "$ (private_recovery_api_version)"> $ (zip_root)/META/recovery-api-version.txt
91. 1163 $ (hide) echo "blocksize $ (board_flash_block_size)" >$ (zip_root)/META/imagesizes.txt
92. 1164 $ (hide) echo "Boot $ (call image-size-from-data-size, $ (board_bootimage_partition_size)" >$ (zip_root)/META/imagesizes.txt
93. 1165 $ (hide) echo "recovery $ (call image-size-from-data-size, $ (board_recoveryimage_partition_size)" >$ (zip_root)/META/imagesizes.txt
94. 1166 $ (hide) echo "system $ (call image-size-from-data-size, $ (board_systemimage_partition_size)" >$ (zip_root)/META/imagesizes.txt
95. 1167 $ (hide) echo "secro $ (call image-size-from-data-size, $ (board_secroimage_partition_size)" >$ (zip_root)/META/imagesizes.txt
96. 1168 $ (hide) echo "userdata $ (call image-size-from-data-size, $ (board_userdataimage_partition_size)" >$ (zip_root)/META/imagesizes.txt
97. 1169 $ (hide) echo "$ (tool_extensions)"> $ (zip_root)/META/tool-extensions.txt
98. 1170 @ # zip everything up, preserving symlinks
99. 1171 $ (hide) (CD $ (zip_root) & zip-qry ../$ (notdir $ @).)
100. 1172 @ # Run fs_config on all the system files in the zip, and save the output
101. 1173 $ (hide) zipinfo-1 $ @ | awk-F/'in in {OFS = "/"}/^ system // {$1 = "system "; print} '| $ (host_out_executables)/fs_config> $ (zip_root)/META/filesystem_config.txt
102. 1174 $ (hide) (CD $ (zip_root) & zip-Q ../$ (notdir $ @) Meta/filesystem_config.txt)

 

It can be seen that a lot of content is added to it.

L1089-1090, create a directory.

L1091-1108 that fills in the contents of the recovery subdirectory. Used to generate recovery. IMG. Including: Kernel image, recovery root file system image, and recovery root file system content:

RECOVERY$ tree -L 2

├── kernel

├── ramdisk

└── RAMDISK

    ├── advanced_meta_init.rc

    ├── data

    ├── default.prop

    ├── dev

    ├── etc

    ├── init

    ├── init.factory.rc

    ├── init.goldfish.rc

    ├── init.mt6516.rc

    ├── init.rc

    ├── meta_init.rc

    ├── proc

    ├── res

    ├── sbin

    ├── sys

    ├── system

    └── tmp

L1109-1125, filling in the contents of the factory subdirectory, not used, including: the image of the kernel

L1126-1143 that fills in the content of the boot subdirectory for generating boot. IMG. Similar to the recovery directory, it includes the image of the kernel, the image of the root file system, and the content of the root file system:

BOOT$ tree -L 2

.

├── kernel

├── ramdisk

└── RAMDISK

    ├── advanced_meta_init.rc

    ├── data

    ├── default.prop

    ├── dev

    ├── init

    ├── init.factory.rc

    ├── init.goldfish.rc

    ├── init.mt6516.rc

    ├── init.rc

    ├── meta_init.rc

    ├── proc

    ├── res -> /system/res

    ├── sbin

    ├── sys

    └── system

L1144-1146, fill in the contents of the radio subdirectory, not used.

L1147-1149 that fills in the contents of the system subdirectory. This is the main content of the upgrade.

L1150-1152 that fills in the content of the data subdirectory. It is not used by default.

L1153-1156, fill in the content of the OTA/bin subdirectory, This is the OTA upgrade your own program. This will happen later.

OTA/bin$ tree

.

├── applypatch

├── applypatch_static

├── check_prereq

└── updater

L1159-1169, fill in the contents of the Meta subdirectory, which contains some additional information required by the OTA script.

L1170-1171 to pack all content. For use in the next stage.

L1173-1174, generate META/filesystem_config.txt and add it to the zip package. This file stores the permissions and owner of the directories and files under the system directory.

$ head META/filesystem_config.txt 

system 0 0 755

system/usr 0 0 755

system/usr/srec 0 0 755

system/usr/srec/config 0 0 755

system/usr/srec/config/en.us 0 0 755

system/usr/srec/config/en.us/grammars 0 0 755

system/usr/srec/config/en.us/grammars/phone_type_choice.g2g 0 0 644

system/usr/srec/config/en.us/grammars/VoiceDialer.g2g 0 0 644

system/usr/srec/config/en.us/grammars/boolean.g2g 0 0 644

system/usr/srec/config/en.us/g2p 0 0 755

Here, the directory is provided by zipinfo-l, and the permission is set by fs_config. The source code of this program is: build/tools/fs_config, where fs_config contains a header file:

54 #include "private/android_filesystem_config.h"

This file (System/CORE/include/private/android_filesystem_config.hIn the form of hardcoding, permissions and owners of directories and files under the system are set. For example:

152     { 00440, AID_ROOT,      AID_SHELL,     "system/etc/init.goldfish.rc" },

153     { 00550, AID_ROOT,      AID_SHELL,     "system/etc/init.goldfish.sh" },

154     { 00440, AID_ROOT,      AID_SHELL,     "system/etc/init.trout.rc" },

155     { 00550, AID_ROOT,      AID_SHELL,     "system/etc/init.ril" },

If you want to upgrade other content, such as bootloader, you can add it here.

Step 2

The compilation script is as follows:

(From: build/CORE/makefile)

1. 1186 name: = $ (target_product)
2. 1187 ifeq ($ (target_build_type), debug)
3. 1188 name: = $ (name) _ debug
4. 1189 endif
5. 1190 name: = $ (name)-Ota-$ (file_name_tag)
6. 1191
7. 1192 internal_ota_package_target: = $ (product_out)/queues (name).zip
8. 1193
9. 1194 $ (internal_ota_package_target): key_cert_pair :=$ (default_key_cert_pair)
10. 1195
11. 1196 ifeq ($ (target_ota_script_mode ),)
12. 1197 # default to "Auto"
13. 1198 $ (internal_ota_package_target): scriptmode: = auto
14. 1199 else
15. 1200 $ (internal_ota_package_target): scriptmode :=$ (target_ota_script_mode)
16. 1201 endif
17. 1202
18. 1203 $ (internal_ota_package_target): $ (built_target_files_package) $ (otatools)
19. 1204 @ echo "package Ota: $ @"
20. 1205 $ (hide)./build/tools/releasetools/ota_from_target_files/
21. 1206-M $ (scriptmode )/
22. 1207-p $ (host_out )/
23. 1208-K $ (key_cert_pair )/
24. 1209 $ (built_target_files_package) $ @

 

The core is a Python script: ota_from_target_files. It uses the zip package generated in the previous step as the input to generate a zip package that can be used for OTA upgrade. The specific content will be further analyzed later.