[VOTE] Change the default branch to "main"

[DemesneGH]

The vote has opened on: https://lists.apache.org/thread/46sgblqjolxfro42ot7ttv577mqv49xz If you have any comments, please feel free to reply to that thread or this issue. Thanks!

[m4sterchain]

Over the past few years, we’ve heard varying perspectives from the community regarding the needs for OPTEE Trusted Application (TA) development. Here’s a brief summary:

• Dependence on the master branch: This allows the use of Rust crates requiring std, which is beneficial for more feature-rich development. However, it may face delays in upstream Rust std support.
• Dependence on the no-std branch: This is suited for TAs with limited functionality, ensuring minimal dependencies and a lightweight codebase.

I assume the proposed changes aim to address the needs of both groups while minimizing maintenance efforts. In addition, could you please elaborate on the following points if this change is merged?

1. What will be the impact on the development of TAs that depend on no-std and master?
2. What are the long-term development plans for maintaining the main, master, and no-std branches? Thanks.

[DemesneGH]

@m4sterchain Yes this proposal mainly aims to simplify future development and maintenance. Since most of the code is shared between std and no-std, merging them into main will eliminate the work to sync pull requests and changes.

1. What will be the impact on the development of TAs that depend on no-std and master?

The build process remains mostly the same (run $ make), but there are minor differences:

• For no-std developers: No additional steps are required. Development keeps same as the original no-std branch.

• For std developers: Developers will need to run $ export STD=y to enable the std feature before running $ source environment.

2. What are the long-term development plans for maintaining the main, master, and no-std branches?

Current Status:

• no-std: A clean branch dedicated to no-std development.

• master: The legacy branch used for std development, and the primary development branch until 2024.

• main: New branch forked from no-std, this branch adds std building support.

After setting main as the default branch (proposed in this VOTE):

• The no-std branch will be deprecated.

• The master branch will be deprecated.

• The main branch will become the only maintenance branch, supporting both std and no-std.

Long-Term Development Plan for the main Branch:

• Add std-specific examples. Since the purpose of std is to provide functionalities that no-std cannot, we can offer examples such as Serde and TLS, which already provided in master branch but not merged into main yet.

• Upstream the OP-TEE target as a Rust Tier 3 target.

• Develop demo projects for specific scenarios, such as Web3.

---

For the reference and clarification, these are the summary of all files in SDK (main branch) root path and their relation with development mode, the "std only" means this file is used only if std is enabled.

files / directories	description	shared / std only / no-std only
.github/workflows, ci, tests	Test both std and no-std for 32-bit and 64-bit TAs. The build is determined by ARCH_HOST, ARCH_TA, and STD environment variables.	Shared
optee-teec	Core library for CA (Client Application).	Shared
optee-utee	Core library for TA (Trusted Application). Most of the code is shared, with minor target-specific differences determined by target_os (optee for std, linux for no-std).	Shared
examples	Code remains the same; ta/Makefile selects the appropriate build tool: cargo for std, Xargo for no-std.	Shared
setup.sh	Installs Rust, cargo, and gcc.	Shared
build_optee_libraries.sh	Builds the necessary OP-TEE libraries for CA and TA, if not available.	Shared
environment	Sets toolchain and library paths.	Shared
rust-toolchain.toml	Specifies the Rust toolchain version.	Shared
aarch64-unknown-optee.json	Specification for AARCH64 OP-TEE target.	std only
arm-unknown-optee.json	Specification for ARM32 OP-TEE target.	std only
all Xargo.toml files	Xargo configuration files pointing to the customized std path.	std only
setup_std_dependencies.sh	Downloads the ported std for OP-TEE.	std only
LICENSE files, docs, etc.	Documentation and licenses.	Shared

[DemesneGH]

@m4sterchain Could you help to review this PR for main:https://github.com/apache/incubator-teaclave-trustzone-sdk/pull/144 ? After this PR merged I think main is ready to be set as default branch.

[b49020]

Yes this proposal mainly aims to simplify future development and maintenance. Since most of the code is shared between std and no-std, merging them into main will eliminate the work to sync pull requests and changes.

+1 for this proposal.