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Please read my background [arm17] email before reviewing this. This is |
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my first news item so please be kind! I have deliberately chosen |
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News-Item-Format 1.0 to include older systems and because I do not need |
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any 2.0 features. |
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|
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|
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Title: ARM 17.0 profile migration with CHOST change |
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Author: James Le Cuirot <chewi@g.o> |
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Content-Type: text/plain |
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Posted: 2018-07-24 |
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Revision: 1 |
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News-Item-Format: 1.0 |
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Display-If-Keyword: arm |
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|
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The new 17.0 profiles for ARM are now officially available. This not |
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only features the PIE migration previously announced for other |
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architectures but also a triplet (CHOST) change for hardfloat systems. |
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|
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In short, the triplet will change from armv7a-hardfloat-linux-gnueabi |
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to armv7a-unknown-linux-gnueabihf or similar. This is to fall in line |
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with what the rest of the Linux community are now using. If the vendor |
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(2nd) part of your triplet is different or missing then you may keep |
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it as it is. The hf ending is what matters. |
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|
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If you are using an unversioned alternative profile such as |
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hardened/linux/arm/armv7a then the default CHOST will have changed for |
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you already. Hopefully, you were shielded from the change by having |
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CHOST explicitly set in your make.conf. In this case, a migration is |
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still required. |
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|
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Changing CHOST is never simple and does carry some risk. We encourage |
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users to migrate but if you do not have sys-devel/llvm on your system |
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and you do not cross-compile for ARM then you may choose to keep your |
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existing CHOST. We will continue to support this to some degree |
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although we cannot promise that other packages will not be affected in |
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future. |
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|
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If you choose not to migrate or your system is not hardfloat then you |
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must ensure that CHOST is explicitly set in make.conf and then proceed |
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with a regular 17.0 migration to deal with PIE as detailed here: |
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|
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https://www.gentoo.org/support/news-items/2017-11-30-new-17-profiles.html |
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|
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Otherwise, if you do wish to migrate then we have written a script to |
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do the necessary steps for you: |
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|
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https://gist.github.com/chewi/1601684ad8f3cf8de0b786c00fa09b3c |
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|
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It takes a minimal backup of the existing toolchain with quickpkg |
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before changing anything but we strongly recommend that you take a |
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full backup first. The script echos each command as it goes along so |
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that you can keep an eye on what it's doing. You are, of course, |
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welcome to tinker with the script or perform the migration manually if |
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you think you know your own system better. It is heavily commented for |
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this reason. |
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|
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If the script fails then you can take remedial action before running |
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it again and it should skip any time-consuming builds that it has |
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already done. If the migration doesn't go to plan then please do seek |
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help in #gentoo-arm. |
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|
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A migration of this kind can justify rebuilding @world but with ARM |
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typically being very slow, the script does just the minimum |
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necessary. You are free to rebuild @world yourself after running it. |
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|
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-- |
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James Le Cuirot (chewi) |
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Gentoo Linux Developer |
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