Android partitions.
●system.img. Contains mainly Android framework.
● boot.img. (kernel/ramdisk) Contains Linux kernel + Android patches.
● vendor.img. Contains SoC-specific code and configurations.
● odm.img. Contains device-specific code and configurations.
● oem.img. Contains OEM/carrier-related configurations and customizations.
● bootloader. Brings up the kernel (vendor-proprietary).
● radio. Modem (proprietary).
Prior to Android 8.0, the vendor, odm, and oem images were optional; files belonging to
these images were placed in boot.img or system.img with symlinks (such as /vendor >
/system/vendor) when absent. Android 8.0 makes the vendor partition mandatory.
目的：
The goal is to modularize Android partitions and make them interchangeable by defining a
core, standard interface between the Android Platform (on system.img) and
vendor-provided code. This standard interface enables the Android Platform to be updated
without affecting the SoC and ODM partitions. For example, it should be possible to
upgrade a device system.img from Android 8.0 to Android P while other images (such as
vendor.img, odm.img, etc.) remain at Android 8.0. This modularity enables timely
Android platform upgrades (such as monthly security updates) without requiring SoC/ODM
partners to update SoC- and device-specific code.