Proposals to improve SWUpdate

Please take into account that most of the items here are proposals. I get some ideas talking with customers, some ideas are my own thoughts. There is no plan when these features will be implemented - this depends if there will be contribution to the project in terms of patches or financial contributions to develop a feature.

Each item listed here contains a status and if the feature is already planned or I am looking for sponsor to implement it. This should avoid double work and make more transparent what is going on with the project.

If you have further ideas about the project, just send your proposal to the Mailing List or post a patch for this document.

Thanks again to all companies that have supported my work up now and to everybody who has contributed to the project, let me bring SWUpdate to the current status !

Legende

Feature’s status

Value	Description
Wait	No activity is planned, just proposal
Design	Design / Concept is done
Planned	Feature will be implemented soon
WIP	Feature is current to be implemented and will be posted
Running	Implemented

Request for Support

Value	Description
None	No sponsoring required
Sponsor	Looking for sponsors to finance the feature
Planned	Feature is already sponsored

Priority

Value	Description
Low	Probably just an idea, feedback from community asked
Medium	Not critical, but nice feature to have
High	Critical feature, it should be implemented soon

Main goal

First goal is to reach a quite big audience, making SWUpdate suitable for a large number of products. This will help to build a community around the project itself.

• Status : Running

• Request for Support : None

Core features

Support for OpenWRT

OpenWRT is used on many routers and has its own way for updating that is not power-cut safe.

• Status: Wait

• Request for Support : Sponsor

• Priority : Low

Software-Software compatibility

SWUpdate has from the early stage a hardware to software compatibility check. In case software is split in several components (like OS and application), it is desirable to have a sort of software compatibility check. For example, SWUpdate verifies if a component (like an application) is compatible with a runningOS and reject the update in case of mismatch.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Support files bigger than 4GB

SWUpdate currently uses CPIO to pack updates in the ‘newc’ and ‘crc’ formats. These formats limit single files to 4GB - 1byte in size, which could become a problem as update size grows.

• Status: Wait

• Request for Support : Sponsor

• Priority : High

Parser

SWUpdate supports two parsers : libconfig and JSON. It would be nice if tools can be used to convert from one format to the other one. Currently, due to some specialties in libconfig, a manual conversion is still required.

• Status: Wait

• Request for Support : None

• Priority : Medium

Fetcher and interfaces

Selective downloading

SWUpdate starts to fetch the whole SWU and process it until an error is found. There are some requests to have a selective downloading, that means SWUpdate will load just the chunks are needed and not the whole SWU. An example for this use case is in case a single SWU contains software for multiple devices, and each of them needs a subset of the whole SWU. Like the delta handler, SWUpdate knows from sw-description which artifacts are to be installed, and reading the stream could decide to skip unnecessary components.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Tools and utilities

Single tool to create SWU

SWUGenerator is a separate project that helps to create SWUs. It is used on not OE projects. In OE, the SWU is created using code in meta-swupdate. This leads to a duplication of code with higher effort to maintain.

Even if it was tried to have the same features, there are some important differences:

• SWUGenerator is able to full understand a sw-description written in libconfig language and to rewrite it. This means it is not yet possible to write sw-description using JSON if SWUGenerato is planned. However, it is possible to split sww-description in small files (for example for the embedded Lua code), and SWUGenerato is able to write the final sw-description combined all include files.

• meta-swupdate is just able to replace variables known by bitbake, but it has no semantic knowledge. It is not possible to use @include directive, but it is possible to use JSON as language.

The logical step will be to use a single tool (SWUGenerator), and let meta-swupdate to use it. To do this, SWUGenerator should be enhance to understand and write sw-description in JSON, too.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Further enhancement to SWUGenerator

SWUGenerator is thought to support multiple subcommands, but it currently supports just “create”. It is thinkable, even if this can be done with other tools, to implement further commands like:

• extract: take a SWU and extracts all artifacts in a directory

• sign: take a SWU and resign with a new key. This is useful when it is required to install a new Software, but the certificate or the key on the device is older and rejects the installation.

• verify: just verify if the SWU is correctly signed.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Lua

• API between SWUpdate and Lua is poorly documented.

• Store in SWUpdate’s repo Lua libraries and common functions to be reused by projects.

• Status : Running

• Request for Support : None

• Priority : Medium

Handlers:

New Handlers

Users develop own custom handlers - I just enforce and encourage everyone to send them and discuss how to integrate custom handler in mainline.

Some ideas for new handlers:

• FPGA updater for FPGA with Flash

• Package handler to install packages (ipk, deb) Packages can be inserted into the SWU and the atomicity is guaranteed by SWUpdate.

• Lua handlers should be added if possible to the project to show how to solve custom install.

• Status : Running

• Request for Support : None

• Priority : Low

Handlers installable as plugin at runtime

The project supports Lua as script language for pre- and postinstall script. It will be easy to add a way for installing a handler at run-time written in Lua, allowing to expand SWUpdate to the cases not covered in the design phase of a product.

Of course, this issue is related to the security features: it must be ensured that only verified handlers can be added to the system to avoid that malware can get the control of the target.

Current release supports verified images. That means that a handler written in Lua could be now be part of the compound image, because a unauthenticated handler cannot run.

• Status : Running

• Request for Support : None

Support for BTRFS snapshot

BTRFS supports subvolume and delta backup for volumes - supporting subvolumes is a way to move the delta approach to filesystems, while SWUpdate should apply the deltas generated by BTRFS utilities.

• Status: Design

• Request for Support : Planned

• Priority : Medium

Security / Crypto engines

• add support for asymmetryc decryption

• rework support for crypto engine - let possible to load multiple libraries at the same time. Currently, there is support for openSSL, WolfSSL and mbedTLS. However, WolfSSL are missing together. There should be a way to select one or more libraries and independently the algorithms that SWUpdate should support. Some hacks are currently built to avoid conflicts (pkcs#7 and CMS are the same thing, but supported by different libraries), and they should be solved.

• add more algorithms for decryption, as AES-CTR can be very useful to decrypt chunks in delta updates.

• Support for TPM2 to store secrets (requires rework above).

• Status: Wait

• Request for Support : Sponsor

• Priority : High

Back-end support (suricatta mode)

Back-end: responsiveness for IPC

Suricatta is implemented as process that launches functions for the selected module. This means that the IPC does not answer if Suricatta is doing something, specially if it is downloading and upgrading the system. This can be enhanced adding a separate thread for IPC and of course all required synchronization with the main modules.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Back-end: check before installing

In some cases (for example, where bandwidth is important), it is better to check if an update must be installed instead of installing and performs checks later. If SWUpdate provides a way to inform a checker if an update can be accepted before downloading, a download is only done when it is really necessary.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Back-end: hawkBit Offline support

There are several discussions on hawkBit’s ML about how to synchronize an offline update (done locally or via the internal Web-server) with the hawkBit’s server. Currently, hawkBit thinks to be the only one deploying software. hawkBit DDI API should be extended, and afterwards changes must be implemented in SWUpdate.

• Status: Wait

• Request for Support : Sponsor

• Priority : Low

Back-end: support for generic down-loader

SWUpdate in down-loader mode works as one-shot: it simply try to download a SWU from a URL. For simple applications, it could be moved into suricatta to detect if a new version is available before downloading and installing.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Back-end: further connectors

Further connectors could be implemented. The structure in SWUpdate is modular, and allows to write new connectors, even in Lua. New connectors could be added if there are requests in this direction.

• Status: Wait

• Request for Support : Sponsor

• Priority : Low

Test and Continuous Integration

The number of configurations and features in SWUpdate is steadily increasing and it becomes urgent to find a way to test all incoming patch to fix regression issues. One step in this direction is the support for Travis build - a set of configuration files is stored with the project and should help to find fast breakages in the build. More in this direction must be done to perform test on targets. A suitable test framework should be found. Scope is to have a “SWUpdate factory” where patches are fast integrated and tested on real hardware.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Binding to languages

libswupdate allows to write an application that can control SWUpdate’s behavior and be informed about a running update. There are bindings for C/C++, Lua and nodejs (just progress).

Applications can be written in other languages, and binding to Python and Rust can be implemented, too.

• Status: Wait

• Request for Support : Sponsor

• Priority : Medium

Documentation

Documentation is a central point in SWUpdate - maintaining it up to date is a must in this project. Help from any user fixing wrong sentence, bad english, adding missing topics is high appreciated.

• Status : Running

• Request for Support : None