寻求Boardfile中加密相关构建选项的说明：TARGET_LEGACY_HW_DISK_ENCRYPTION等

Hey there! I’ve spent time digging through Android’s build system and device-specific source code to unpack these obscure encryption flags—since official documentation for these low-level, vendor-specific options is pretty scarce. Here’s a breakdown of each one:

• TARGET_LEGACY_HW_DISK_ENCRYPTION
  This flag enables legacy hardware-backed disk encryption workflows, typically for older devices that don’t support modern Keymaster or newer hardware security module (HSM) features. It falls back to older encryption implementations (often tied to early Qualcomm QSEE-based systems) that aren’t compatible with newer standards like SWv8 encryption.

• TARGET_SWV8_DISK_ENCRYPTION
  Enables the Software Version 8 disk encryption stack. This is a software-only encryption implementation, used when a device lacks hardware encryption acceleration or requires compatibility with a software-focused encryption pipeline. Unlike hardware-backed options, it relies entirely on Android’s native software encryption libraries rather than a dedicated HSM.

• TARGET_CRYPTFS_HW_PATH
  A build variable that specifies the file system path to the hardware encryption module interface. It tells the Android cryptfs (encrypted file system) component where to find the underlying hardware encryption service (e.g., a Qualcomm QSEE interface) to offload encryption operations to hardware.

• TARGET_KEYMASTER_WAIT_FOR_QSEE
  Controls the startup timing of the Keymaster service. When enabled, Keymaster will delay its initialization until the Qualcomm Secure Execution Environment (QSEE) is fully ready. This is critical because many hardware-backed encryption operations depend on QSEE’s secure runtime environment—skipping this wait can lead to Keymaster startup failures or broken encryption functionality.

Keep in mind that these are mostly vendor-specific flags (heavily used by Qualcomm-based devices) and are often defined in device-specific build configurations rather than core Android build docs. You’ll find more context by checking the device/ directory for your target device or the build/core encryption-related configs in the Android Open Source Project repo.

内容的提问来源于stack exchange，提问作者user674907