1.安装64位linux系统，我用的是deepin os 15.3
2、将系统升级到最新版本
sudo apt-get update && sudo apt-get upgrade
3.安装编译必须的插件（我是直接在网上抄的别人搭建cm13编译环境时写的）deepin安装OpenJDK7网上也有办法
sudo apt-get install git-core gnupg flex bison gperf libsdl1.2-dev libesd0-dev libwxgtk2.8-dev squashfs-tools build-essential zip curl libncurses5-dev zlib1g-dev openjdk-7-jre openjdk-7-jdk pngcrush schedtool libxml2 libxml2-utils xsltproc lzop libc6-dev schedtool g++-multilib lib32z1-dev lib32ncurses5-dev gcc-multilib maven tmux screen w3m ncftp liblz4-tool ccache
然后切换jdk gcc g++版本
4、建立repo（谷歌的不能用，所以找国内的镜像站，我的repo，aosp，android sdk都是从国内镜像站获取的，如清华的，中科大的）
mkdir ~/bin
PATH=~/bin:$PATH
curl https://storage-googleapis.lug.ustc.edu.cn/git-repo-downloads/repo > ~/bin/repo
chmod a+x ~/bin/repo
5、建立源码文件夹
mkdir ~/OMNI && cd ~/OMNI
6.创建repo链接，（https://github.com/omnirom/android））
repo init -u https://github.com/omnirom/android.git -b android-7.1
7.更换aosp镜像地址（更换成清华或中科大aosp镜像地址，原因……）
sudo gedit ~/OMNI/.repo/manifest.xm
找到下面这句
fetch="https://android.googlesource.com"
将其更改为下面的其中一个：（自己视情况选择）
清华大学AOSP镜像地址：fetch="https://aosp.tuna.tsinghua.edu.cn"
中国科学技术大学AOSP镜像地址：fetch="git://mirrors.ustc.edu.cn/aosp"
8.同步源码
repo sync -c -f -j8 --force-sync --no-clone-bundle
这是一个漫长的过程，100M宽带都同步了几天，中间出现断网，就再输入一次上面的指令继续同步，为此我在网上找了个自动续传的脚本，方便多了
9.解包官方recovery（第三方recovery也行）
工具：CarlivImageKitchen（Windows和Linux平台都有）
在xda淘的，mt6752和骁龙821，我都试过，解包，修改，打包，刷入，完全没有问题
解包会得到kernel，recovery.fstab，以及很多参数，都是有用的
10.为自己的机型准备devices
（1）.弄清楚手机的配置参数
（2）.到github找相近机型的device，有参考的省事多了
（3）.Omni源码目录下新建device目录，OMNI/device/meizu/m1note
（4）.OMNI/device/meizu/m1note下新建Android.mk，AndroidProducts.mk，BoardConfig.mk，omni_m1note.mk
（5）把官方boot或recovery解压得到的kernel，recovery.fstab拷贝过来，然后修改各个文件的内容，主要修改BoardConfig.mk，因为只编译recovery，里面内容较少，容易修改，需要的东西我们解包recovery是已经获取了，其他文件内容更少，也容易修改
（6）查看手机分区挂载点，手机开机，打开usb调试，连接电脑
Adb shell
ls -l /dev/block/platform/mtk-msdc.0/by-name/
不同手机会有点区别，尤其是/platform/mtk-msdc.0这里，我是通过cat proc/mounts命令找到的
（7）利用以上信息修改recovery.fstab，recovery解包的recovery.fstab不一定正确完整
（8）接下来完成创建的4个.mk文件
Android.mk
ifneq ($(filter m1note,$(TARGET_DEVICE)),)
LOCAL_PATH := $(call my-dir)
include $(call all-makefiles-under,$(LOCAL_PATH))
Endif
AndroidProducts.mk
PRODUCT_MAKEFILES := $(LOCAL_DIR)/omni_m1note.mk
Omni_m1note.mk
PRODUCT_RELEASE_NAME := m1note
# Inherit from the common Open Source product configuration
$(call inherit-product, $(SRC_TARGET_DIR)/product/aosp_base_telephony.mk)
# Inherit from our custom product configuration
$(call inherit-product, vendor/omni/config/common.mk)
PRODUCT_PACKAGES +=
charger_res_images
charger
## Device identifier. This must come after all inclusions
PRODUCT_DEVICE := m1note
PRODUCT_MODEL := m1note
PRODUCT_NAME := omni_m1note
PRODUCT_BRAND := meizu
PRODUCT_MANUFACTURER := meizu
这三个文件很简单，改动也简单
（8）最重要的BoardConfig.mk
LOCAL_PATH := device/meizu/m1note
#下面的复制相同cpu机型的，或者自己查手机cpu信息，m1note只能在安卓4.4解锁，所以是32位
# Architecture
TARGET_ARCH := arm
TARGET_NO_BOOTLOADER := true
TARGET_BOARD_PLATFORM := mt6752
TARGET_CPU_ABI := armeabi-v7a
TARGET_CPU_ABI2 := armeabi
TARGET_ARCH_VARIANT := armv7-a-neon
TARGET_CPU_VARIANT := generic
TARGET_CPU_CORTEX_A53 := true
TARGET_CPU_SMP := true
ARCH_ARM_HAVE_TLS_REGISTER := true
TARGET_NO_FACTORYIMAGE := true
BOARD_MTK_LIBSENSORS_NAME :=
BOARD_MTK_LIB_SENSOR :=
#Bootloader
TARGET_BOOTLOADER_BOARD_NAME := m1note
#内核，用CarlivImageKitchen64解包官方boot或recovery就能得到这些
#Kernel
#内核路径
TARGET_PREBUILT_KERNEL := $(LOCAL_PATH)/kernel
#mtk需要这个
BOARD_CUSTOM_BOOTIMG_MK := $(LOCAL_PATH)/mkmtkboot.mk
BOARD_KERNEL_CMDLINE := bootopt=64S3,32S1,32S1
BOARD_KERNEL_BASE := 0x40078000
BOARD_KERNEL_PAGESIZE := 2048
BOARD_MKBOOTIMG_ARGS :=
--base 0x40000000
--pagesize 2048
--kernel_offset 0x00008000
--ramdisk_offset 0x04000000
--second_offset 0x00f00000
--tags_offset 0x0e000000
#分区大小，adb shell,cat /proc/partinfo,分区size要从十六进制转10进制
#Partition sizes
BOARD_BOOTIMAGE_PARTITION_SIZE := 16777216
BOARD_RECOVERYIMAGE_PARTITION_SIZE := 16777216
BOARD_SYSTEMIMAGE_PARTITION_SIZE := 1610612736
BOARD_USERDATAIMAGE_PARTITION_SIZE := 13217824768
BOARD_CACHEIMAGE_PARTITION_SIZE := 117440512
BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE := ext4
BOARD_FLASH_BLOCK_SIZE := 131072
BOARD_HAS_LARGE_FILESYSTEM := true
TARGET_RUNNING_WITHOUT_SYNC_FRAMEWORK := true
#Recovery
#编写好的recovery.fstab的路径
TARGET_RECOVERY_FSTAB := $(LOCAL_PATH)/recovery.fstab
TW_THEME := portrait_hdpi
BOARD_HAS_NO_SELECT_BUTTON := true
DEVICE_RESOLUTION := 1080x1920
TW_NO_USB_STORAGE := true
RECOVERY_GRAPHICS_USE_LINELENGTH := true
BOARD_HAS_NO_SELECT_BUTTON := true
BOARD_HAS_NO_SELECT_BUTTON := true
TARGET_RECOVERY_PIXEL_FORMAT := "RGBA_8888"
RECOVERY_FONT := roboto_15x24.h
WITH_DEXPREOPT := true
我的魅蓝m1note屏幕是倒的，所以加了这句
BOARD_HAS_FLIPPED_SCREEN := true
还有一些驱动，很多机型编译twrp不需要配置这些
TW_BRIGHTNESS_PATH := /sys/devices/platform/leds-mt65xx/leds/lcd-backlight/brightness
# The path to a temperature sensor
TW_CUSTOM_CPU_TEMP_PATH := /sys/class/thermal/thermal_zone1/temp
# USB Mounting
TARGET_USE_CUSTOM_LUN_FILE_PATH := /sys/class/android_usb/f_mass_storage/lun/file
TW_MTP_DEVICE := /dev/mtp_usb
#默认中文，网上没找到方法，自己想到把汉化文件放进源码，设置位默认语言
TW_EXTRA_LANGUAGES := true
#cp bootable/recovery/gui/theme/extra-languages/languages/zh_CN.xml bootable/recovery/gui/theme/common/languages/cn.xml
TW_DEFAULT_LANGUAGE := cn
#存储，m1note不知SD扩展，设置内置存储挂载点/data/media，清除data时会跳过/data/media
# Storages
BOARD_HAS_NO_MISC_PARTITION := true
TW_INTERNAL_STORAGE_PATH := "/data/media"
TW_INTERNAL_STORAGE_MOUNT_POINT := "data"
TW_FLASH_FROM_STORAGE := true
RECOVERY_SDCARD_ON_DATA := true
11.编译
cd ~/OMNI
. build/envsetup.sh
lunch
选择机型
make -j8 recoveryimage
正常编译几分钟就好，报错了就复制错误代码去GitHub或Google搜
12.mtk机型
编译之后，高通骁龙821的twrp recovery能直接刷入使用，mtk的mt6752的twrp recovery刷入无法启动
用CarlivImageKitchen解包生成的recovery.img发现解包ramdisk失败
网上找相关资料，都只说到mtk机型编译生成的recovery.img还需要处理
猜想可能是和mtk的512有关，所以又把out目录里的ramdisk相关的.cpio文件解压，重新打包进recovery
后来发现还可以在编译前配置一下
在BoardConfig.mk里添加
BOARD_HAS_MTK := true
BOARD_CUSTOM_BOOTIMG_MK := $(DEVICE_FOLDER)/mkmtkbootimg.mk
再新建mkmtkbootimg.mk文件
mkmtkbootimg.mk的内容：
# Copyright (C) 2013 The Android Open-Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# can this be done in bash? credits go to bgcngm
define make_header
perl -e 'print pack("a4 L a32 a472", "x88x16x88x58", $$ARGV[0], $$ARGV[1], "xFF"x472)' $(1) $(2) > $(3)
endef
# this is overriding targets from build/core/Makefile
$(INSTALLED_KERNEL_TARGET).mtk.header: $(INSTALLED_KERNEL_TARGET)
size=$$($(call get-file-size,$(INSTALLED_KERNEL_TARGET)));
$(call make_header, $$((size)), "KERNEL", $@)
$(INSTALLED_KERNEL_TARGET).mtk: $(INSTALLED_KERNEL_TARGET).mtk.header
$(call pretty,"Adding MTK header to kernel.")
cat $(INSTALLED_KERNEL_TARGET).mtk.header $(INSTALLED_KERNEL_TARGET)
> $@
$(INSTALLED_RAMDISK_TARGET).mtk.header: $(INSTALLED_RAMDISK_TARGET)
size=$$($(call get-file-size,$(INSTALLED_RAMDISK_TARGET)));
$(call make_header, $$((size)), "ROOTFS", $@)
$(INSTALLED_RAMDISK_TARGET).mtk: $(INSTALLED_RAMDISK_TARGET).mtk.header
$(call pretty,"Adding MTK header to ramdisk.")
cat $(INSTALLED_RAMDISK_TARGET).mtk.header $(INSTALLED_RAMDISK_TARGET)
> $@
$(PRODUCT_OUT)/recovery_kernel.mtk.header: $(recovery_kernel)
size=$$($(call get-file-size,$(recovery_kernel)));
$(call make_header, $$((size)), "KERNEL", $@)
$(PRODUCT_OUT)/recovery_kernel.mtk: $(PRODUCT_OUT)/recovery_kernel.mtk.header
$(call pretty,"Adding MTK header to recovery kernel.")
cat $(PRODUCT_OUT)/recovery_kernel.mtk.header $(recovery_kernel) > $@
$(recovery_ramdisk).mtk.header: $(recovery_ramdisk)
size=$$($(call get-file-size,$(recovery_ramdisk)));
$(call make_header, $$((size)), "RECOVERY", $@)
$(recovery_ramdisk).mtk: $(MKBOOTIMG) $(recovery_ramdisk).mtk.header
$(call pretty,"Adding MTK header to recovery ramdisk.")
cat $(recovery_ramdisk).mtk.header $(recovery_ramdisk) > $@
INTERNAL_MTK_BOOTIMAGE_ARGS :=
--kernel $(INSTALLED_KERNEL_TARGET).mtk
--ramdisk $(INSTALLED_RAMDISK_TARGET).mtk
$(INSTALLED_BOOTIMAGE_TARGET): $(MKBOOTIMG)
$(INSTALLED_RAMDISK_TARGET).mtk $(INSTALLED_KERNEL_TARGET).mtk
$(call pretty,"Target boot image: $@")
$(MKBOOTIMG) $(INTERNAL_MTK_BOOTIMAGE_ARGS) $(BOARD_MKBOOTIMG_ARGS)
--output $@
$(hide) $(call assert-max-image-size,$@,
$(BOARD_BOOTIMAGE_PARTITION_SIZE),raw)
@echo -e ${CL_CYN}"Made boot image: $@"${CL_RST}
INTERNAL_MTK_RECOVERYIMAGE_ARGS :=
--kernel $(PRODUCT_OUT)/recovery_kernel.mtk
--ramdisk $(recovery_ramdisk).mtk
$(INSTALLED_RECOVERYIMAGE_TARGET): $(MKBOOTIMG)
$(recovery_ramdisk).mtk $(PRODUCT_OUT)/recovery_kernel.mtk
@echo -e ${CL_CYN}"----- Making recovery image ------"${CL_RST}
$(MKBOOTIMG) $(INTERNAL_MTK_RECOVERYIMAGE_ARGS)
$(BOARD_MKBOOTIMG_ARGS) --output $@
$(hide) $(call assert-max-image-size,$@,
$(BOARD_RECOVERYIMAGE_PARTITION_SIZE),raw)
@echo -e ${CL_CYN}"Made recovery image: $@"${CL_RST}