diff --git a/README.md b/README.md index fc345a8dc91566329533bf426ae7d55ea7522956..b916bc8286fccf6b74719d9cce4d5a45070c7123 100755 --- a/README.md +++ b/README.md @@ -82,6 +82,44 @@ For example, to add the updater for Hi3516D V300, add the following code to the Add the compilation configuration to the **build\_updater\_image.sh** script, which is stored in the **build** repository and called by the OpenHarmony compilation system. +## AB Streaming Update + +User devices may not always have sufficient space on the data partition for downloading OTA upgrade packages. Furthermore, entering the microsystem for upgrades sometimes impacts the user experience. To resolve these issues, OpenHarmony has introduced support for AB Streaming Updates. This feature allows downloading data chunks (Chunks) to be written directly to the inactive B partition, eliminating the need to store the chunks or the full update package on the data partition. Simultaneously, users can continue operating their devices on the active A partition while the update is applied to the inactive B partition, bypassing the need to enter the updater microsystem. + +### Key Technologies + +1、 Supports independent AB partition upgrades, enabling seamless updates. + +2、 Supports resumable streaming updates, allowing updates to continue after interruptions like network disconnections or user pauses. + +3、 Supports multiple security checks, including hash verification for each data chunk and integrity verification for each image after the update. + +4、 Supports exception rollback, ensuring the device automatically reverts to the stable partition upon upgrade failure for a consistent user experience. + +5、 Supports customizable streaming data chunk size, adjustable based on the device's data partition capacity. + +### Packaging Process + +The AB Streaming Update modifies the packaging of standard AB differential or full OTA packages. new and diff operations larger than the specified data size requirement in this document are split into smaller chunks. All delta dependency files are then packaged into the update.bin file using the TLV format. + +1、 Split diff/new content exceeding 45KB + +Input parameters: pkgdiff, new commands. + +​Output: For the pkgdiff command, attempt to generate a diff file. If the diff file is larger than 45KB, split the pkgdiff operation into multiple smaller pkgdiff commands until each generated diff file is under 45KB. For the new command, directly check the block content size. Split any block not meeting the size requirement into multiple new commands. + +2、​Calculate img blocks excluding those operated on in the action list + +Input parameters: All blocks operated on in the action list, Total blocks of the img. + +Output: The complement set of the two. Sort the required copy blocks in ascending order. Group consecutive blocks into sets. Combine them into copy commands using the standard new command format. + +3、Package action, diff, etc., into update.bin per TLV format + +Input parameters: transfer.list, new.dat, patch.dat. + +Output: Package each line of the transfer.list as a chunk. Locate the dependent content in new.dat and patch.dat. Generate update.bin in TLV format. + ## Repositories Involved Update subsystem diff --git a/README_zh.md b/README_zh.md index 056cecc162ee834a2b84a7257a759ef682fc6e3d..83dbf2704b44590e26929b5e0ba1d08d1b43ef84 100755 --- a/README_zh.md +++ b/README_zh.md @@ -91,6 +91,44 @@ b、 产品中添加需要编译的组件 编译配置在build仓下，build\_updater\_image.sh 脚本中，该脚本由OHOS 编译系统调用。 +## AB流式升级 + +用户设备并非在data分区上总是有足够的空间用于下载OTA升级包，同时用户有时候不需要进入小系统升级来影响设备体验。为了解决这些问题，OpenHarmony中添加了对AB流式升级的更新，可以在下载数据块Chunk写入备用B分区，而无需将数据块或者升级包存储到data分区；同时不需要进入updater小系统进行升级，用户设备操作在活跃A分区，更新在备用B分区。 + +### 关键技术 + +1、 支持AB分区独立升级，实现无缝更新。 + +2、 支持流式升级断点续传，在网络断开连接、用户操作暂停等操作后，重新点击下载并更新可以实现继续更新。 + +3、 支持多种安全校验，每个数据块Chunk会带有哈希校验，更新完后会对每个镜像进行完整性校验。 + +4、 支持异常回滚机制，确保升级失败时自动恢复到稳定分区，确保用户体验。 + +5、 支持流式传输数据块自定义，可以根据设备data分区大小自调整。 + +### 做包流程 + +在AB流式升级当中，修改的重点是在原AB差分或者全量升级包的基础上，对大于本文档数据大小要求的new和diff操作要进行更小的切片，并按照TLV格式把差分依赖文件都封装到update.bin文件中 + +1、 切割内容大于45KB的diff/new + +输入参数:pkgdiff、new命令 + +输出结果:对于pkgdiff命令尝试生成diff文件，如果diff文件大于45KB，就把pkgdiff命令分成多个pkgdiff，直到每个pkgdiff命令的diff文件大小都小于45KB。new命令直接判断block的内容大小，不满足大小的，就分割成多个new命令 + +2、计算img总块除去action列表中操作的块 + +输入参数：action列表中所有操作过的块，img总块 + +输出参数：两者补集，即将需要copy的块进行升序排序，连续的组成集合，按照原有new的格式进行组合成copy命令 + +3、根据TLV格式封装action及diff等内容到update.bin + +输入参数:transfer.list、new.dat、patch.dat + +输出结果:将transfer.list每一行封装成一个chunk，依赖的内容在new.dat和patch.dat中查找，并按TLV格式生成update.bin + ## 相关仓 [升级子系统](https://gitee.com/openharmony/docs/blob/master/zh-cn/readme/%E5%8D%87%E7%BA%A7%E5%AD%90%E7%B3%BB%E7%BB%9F.md) @@ -100,4 +138,3 @@ b、 产品中添加需要编译的组件 [build](https://gitee.com/openharmony/build) [productdefine\_common](https://gitee.com/openharmony/productdefine_common) -