爲Nexus5編譯AndroidL固件

接前一篇文章使用Android Studio查看Android Lollipop源碼, 我們知道,僅僅看代碼,提高是比較有限的,而且理解起來也比較膚淺,往往過目就忘. 而自己寫過的代碼,往往會印象比較深刻,在寫的時候也會比較容易理解流程. 所以我們在看代碼的同時, 如果能修改代碼, 在手機上跑起來並看到修改的效果,這無疑會加快看代碼的效率和積極性. 所以這篇文章,就講解一下如何自己編譯AndroidL的源碼,並且在Nexus5上跑起來. 至於爲何需要自己編譯固件,而不是直接安裝Google給出的工廠固件?原因是Google給出的工廠固件是User版本,是沒法隨心所欲Push東西進去的. 所以我們需要編譯自己的Userdebug版本.

本文假設你已經下載了AndroidL的源碼,並且有一臺Nexus5手機(手機系統開發人員必備), 如果你還沒有AndroidL的源碼,或者你有源碼但是沒有配置編譯的環境,那麼 Initializing a Build Environment 和Downloading the Source這兩篇文章你應該先去看一下(我又一次假設你會翻牆,如果你不會翻牆,那麼下代碼也是一個痛苦的事情). 這後面的教程Google官網也有教程.所以我只針對Nexus5進行講解.

另外你需要知道AOSP,AOSP即Android Open Source Project 漢語意思是：谷歌開放源代碼項目.我們通過Google官方下載的源代碼,就是AOSP的代碼, 其中是不包含Google開發的那些個應用的,各個廠商拿到的也是這個版本,在這個版本的基礎上進行修改. 而Google發佈的工廠固件則是包含全套Google服務的. 廠商如果想安裝Google服務,就需要過Google的那一套認證,比較麻煩,而且價格不菲,鑑於Google在國內的尷尬地位,國內很多廠商都沒有過這個認證.

1. 初始化編譯環境

1	. build/envsetup.sh

2. 加載機型

lunch

3. 選擇要編譯的機器

You're building on Linux

Lunch menu... pick a combo:
     1. aosp_arm-eng
     2. aosp_arm64-eng
     3. aosp_mips-eng
     4. aosp_mips64-eng
     5. aosp_x86-eng
     6. aosp_x86_64-eng
     7. aosp_shamu-userdebug
     8. aosp_manta-userdebug
     9. full_fugu-userdebug
     10. aosp_fugu-userdebug
     11. aosp_grouper-userdebug
     12. aosp_tilapia-userdebug
     13. aosp_deb-userdebug
     14. aosp_flo-userdebug
     15. aosp_mako-userdebug
     16. aosp_hammerhead-userdebug
     17. aosp_flounder-userdebug
     18. mini_emulator_x86_64-userdebug
     19. mini_emulator_arm-userdebug
     20. mini_emulator_x86-userdebug
     21. mini_emulator_mips-userdebug
     22. mini_emulator_arm64-userdebug

3.1 機型對照表

DEVICE	CODE NAME	BUILD CONFIGURATION
Nexus 6	shamu	aosp_shamu-userdebug
Nexus Player	fugu	aosp_fugu-userdebug
Nexus 9	volantis (flounder)	aosp_flounder-userdebug
Nexus 5 (GSM/LTE)	hammerhead	aosp_hammerhead-userdebug
Nexus 7 (Wi-Fi)	razor (flo)	aosp_flo-userdebug
Nexus 7 (Mobile)	razorg (deb)	aosp_deb-userdebug
Nexus 10	mantaray (manta)	full_manta-userdebug
Nexus 4	occam (mako)	full_mako-userdebug
Nexus 7 (Wi-Fi)	nakasi (grouper)	full_grouper-userdebug
Nexus 7 (Mobile)	nakasig (tilapia)	full_tilapia-userdebug
Galaxy Nexus (GSM/HSPA+)	yakju (maguro)	full_maguro-userdebug
Galaxy Nexus (Verizon)	mysid (toro)	aosp_toro-userdebug
Galaxy Nexus (Experimental)	mysidspr (toroplus)	aosp_toroplus-userdebug
PandaBoard (Archived)	panda	aosp_panda-userdebug
Motorola Xoom (U.S. Wi-Fi)	wingray	full_wingray-userdebug
Nexus S	soju (crespo)	full_crespo-userdebug
Nexus S 4G	sojus (crespo4g)	full_crespo4g-userdebug3.2

3.2 三個版本說明版本

BUILDTYPE	USE
user	limited access; suited for production
userdebug	like “user” but with root access and debuggability; preferred for debugging
eng	development configuration with additional debugging tools

選擇aosp_hammerhead-userdebug之後,會有下面的確認信息:

============================================
PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=5.0.50.50.50.50
TARGET_PRODUCT=aosp_hammerhead
TARGET_BUILD_VARIANT=userdebug
TARGET_BUILD_TYPE=release
TARGET_BUILD_APPS=
TARGET_ARCH=arm
TARGET_ARCH_VARIANT=armv7-a-neon
TARGET_CPU_VARIANT=krait
TARGET_2ND_ARCH=
TARGET_2ND_ARCH_VARIANT=
TARGET_2ND_CPU_VARIANT=
HOST_ARCH=x86_64
HOST_OS=linux
HOST_OS_EXTRA=Linux-3.13.0-37-generic-x86_64-with-Ubuntu-14.10-utopic
HOST_BUILD_TYPE=release
BUILD_ID=AOSP
OUT_DIR=out
============================================

4. 生成驅動目錄

接下來需要在Android官網下載 Nexus5所需要的驅動:

HARDWARE COMPONENT	COMPANY	DOWNLOAD	MD5 CHECKSUM	SHA-1 CHECKSUM
NFC, Bluetooth, Wi-Fi	Broadcom	Link	2c398994e37093df51b105d63f0eb611	991346159c95ae75f760014a6822b8b3e8667700
Camera, Sensors, Audio	LG	Link	74cf8235e6bb04da28b2ff738b13eee9	175dd5bae81bb54030d072cb0f0b4ec81eb3f71f
Graphics, GSM, Camera, GPS, Sensors, Media, DSP, USB	Qualcomm	Link	0a43395e175d3de3dc312d8abdcb4f20	007cf9d49f0409d5c703e7f2811fd153fee22353

下載完成後,解壓出來是三個.sh文件,放到Android源碼目錄下面,然後執行.會將相關驅動放到vender目錄下面.

5. 執行編譯命令

make -j8

如果沒有出錯的話,在經過漫長的時間之後,編譯成功:

Installed file list: out/target/product/hammerhead/installed-files.txt
Target system fs image: out/target/product/hammerhead/obj/PACKAGING/systemimage_intermediates/system.img
Running:  mkuserimg.sh -s out/target/product/hammerhead/system out/target/product/hammerhead/obj/PACKAGING/systemimage_intermediates/system.img ext4 system 1073741824 -L system out/target/product/hammerhead/root/file_contexts
make_ext4fs -s -T -1 -S out/target/product/hammerhead/root/file_contexts -L system -l 1073741824 -a system out/target/product/hammerhead/obj/PACKAGING/systemimage_intermediates/system.img out/target/product/hammerhead/system
Creating filesystem with parameters:
    Size: 1073741824
    Block size: 4096
    Blocks per group: 32768
    Inodes per group: 8192
    Inode size: 256
    Journal blocks: 4096
    Label: system
    Blocks: 262144
    Block groups: 8
    Reserved block group size: 63
Created filesystem with 1445/65536 inodes and 85879/262144 blocks
Install system fs image: out/target/product/hammerhead/system.img
out/target/product/hammerhead/system.img+out/target/product/hammerhead/obj/PACKAGING/recovery_patch_intermediates/recovery_from_boot.p maxsize=1096212480 blocksize=135168 total=336629666 reserve=11083776

6. 刷機命令

Nexus5關機狀態下,長按音量下+電源,即可進入recovery模式, 然後在源碼根目錄下執行下面命令:

1	fastboot -w flashall

刷機成功後會自動重啓

~/Android-SourceCode fastboot -w flashall
target reported max download size of 1073741824 bytes
Creating filesystem with parameters:
    Size: 13725835264
    Block size: 4096
    Blocks per group: 32768
    Inodes per group: 8144
    Inode size: 256
    Journal blocks: 32768
    Label: 
    Blocks: 3351034
    Block groups: 103
    Reserved block group size: 823
Created filesystem with 11/838832 inodes and 93654/3351034 blocks
Creating filesystem with parameters:
    Size: 734003200
    Block size: 4096
    Blocks per group: 32768
    Inodes per group: 7472
    Inode size: 256
    Journal blocks: 2800
    Label: 
    Blocks: 179200
    Block groups: 6
    Reserved block group size: 47
Created filesystem with 11/44832 inodes and 5813/179200 blocks
--------------------------------------------
Bootloader Version...: HHZ12d
Baseband Version.....: M8974A-2.0.50.2.22
Serial Number........: 08ade1a513dc087b
--------------------------------------------
checking product...
OKAY [  0.100s]
sending 'boot' (8950 KB)...
OKAY [  0.500s]
writing 'boot'...
OKAY [  0.784s]
sending 'recovery' (9672 KB)...
OKAY [  0.556s]
writing 'recovery'...
OKAY [  0.814s]
erasing 'system'...
OKAY [  1.166s]
sending 'system' (328187 KB)...
OKAY [ 10.501s]
writing 'system'...
OKAY [ 23.623s]
erasing 'userdata'...
OKAY [ 14.657s]
sending 'userdata' (137318 KB)...
OKAY [  4.520s]
writing 'userdata'...
OKAY [  9.776s]
erasing 'cache'...
OKAY [  0.618s]
sending 'cache' (13348 KB)...
OKAY [  0.630s]
writing 'cache'...
OKAY [  1.070s]
rebooting...

finished. total time: 70.095s