From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Kettenis Date: Sat, 29 Jun 2019 18:50:14 +0200 (CEST) Subject: [U-Boot] What if ATF can be part of U-Boot source, like SPL? In-Reply-To: (message from Jagan Teki on Sat, 29 Jun 2019 20:32:00 +0530) References: Message-ID: <543892ed970bae77@bloch.sibelius.xs4all.nl> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de > From: Jagan Teki > Date: Sat, 29 Jun 2019 20:32:00 +0530 > > In terms of code maintenance and development feasibility it is always > a better approach to have out-of-tree code or binary to be part of > in-house source tree. I disagree. This strategy often leads to diverging codebases where local improvements are not fed back upstream and/or not picking up bug- and security fixes from upstream. It also means that developers of non-ARM U-Boot platforms will have to check out the full ATF source tree. > This is what exactly it was done for SPL, if I'm not wrong. So can we > do the same thing for ATF on ARM64 SoCs? SPL and U-Boot proper share a lot of code. I'd say it is totally different. > We are using ATF (on Allwinner) to switch EL3 to EL2 for start loading > U-Boot proper and minimal PSCI, PMIC initialization. So assuming the > functionality of ATF (like here) is limited so the code it require can > be limited too, so why can't this code to be part of U-Boot tree? > > This would ultimately avoid out-off-tree ATF builds with associated > variable exporting during u-boot builds. I don't see this as a huge issue. For OpenBSD we already have the (small) build infrastructure to handle this. > More over this idea would also help to design a single-step bootloader > where it can't depends on out-of-tree sources. > > Code sync from ATF source to U-Boot can be possible in-terms licensing > point-of-view since ATF licensed under BSD-3-Clause. > > I'm thinking this can be a worth-idea to look at it and I'm sure It > may require some hard changes and other things to consider but just > posted to understand how hard or feasible or meaningful it is? > > Feel free for any comments? I don't think this makes a lot of sense. Apart from what I wrote above, some platforms use U-Boot as a payload for ATF (or TF-A as it is called now) instead of the other way around. It also makes it difficult to do development on platforms where ATF sources have not yet been upstreamed.