how to simply build a common toolchain for multiple developers?

how to simply build a common toolchain for multiple developers?

[Robert P. J. Day]

  (sort of a "how to do this?" question, but also wondering if this is
covered in the docs so i could have found it there.)

  over the last week, two separate colleagues asked how to build a
generic aarch64 toolchain they could subsequently use for builds so
that they don't have to reproduce all that work in brand new builds,
and since it's been a while since i dug into that, i'll ask here and
make sure it's properly written up afterwards. (i think alexander k.
explained some of this before, so i'm about to dig out his earlier
post.)

  the idea is to create (i'm assuming with "bitbake -c populate_sdk
...) the appropriate SDK, then install it and use it from then on when
building other aarch64 images. the goal is a totally generic toolchain
-- no customization; that is, create the simplest toolchain that has
the widest application for developers who just want to build a new
aarch64 image.

  while i'm getting ready to build and test this very thing, i'm
going to assume that i could start with a fresh aarch64 build, and
just:

  $ bitbake -c populate_sdk core-image-minimal

that is, no customization for either host or target -- just build the
SDK .sh script, after which i can run it and install the SDK in a
common location accessible to others, after which ... what?

  if someone wanted to do a fresh (from scratch) aarch64-based build,
would they simply need to run the SDK's env setup script, then proceed
normally to take advantage of all that earlier work? or is there more
to it? it seems like a simple enough request, but i don't see it
explained in the SDK manual.

  thoughts?

rday

Re: [docs] how to simply build a common toolchain for multiple developers?

[Richard Purdie]

On Sun, 2021-09-05 at 08:19 -0400, Robert P. J. Day wrote:
>   (sort of a "how to do this?" question, but also wondering if this is
> covered in the docs so i could have found it there.)
> 
>   over the last week, two separate colleagues asked how to build a
> generic aarch64 toolchain they could subsequently use for builds so
> that they don't have to reproduce all that work in brand new builds,
> and since it's been a while since i dug into that, i'll ask here and
> make sure it's properly written up afterwards. (i think alexander k.
> explained some of this before, so i'm about to dig out his earlier
> post.)
> 
>   the idea is to create (i'm assuming with "bitbake -c populate_sdk
> ...) the appropriate SDK, then install it and use it from then on when
> building other aarch64 images. the goal is a totally generic toolchain
> -- no customization; that is, create the simplest toolchain that has
> the widest application for developers who just want to build a new
> aarch64 image.
> 
>   while i'm getting ready to build and test this very thing, i'm
> going to assume that i could start with a fresh aarch64 build, and
> just:
> 
>   $ bitbake -c populate_sdk core-image-minimal
> 
> that is, no customization for either host or target -- just build the
> SDK .sh script, after which i can run it and install the SDK in a
> common location accessible to others, after which ... what?
> 
>   if someone wanted to do a fresh (from scratch) aarch64-based build,
> would they simply need to run the SDK's env setup script, then proceed
> normally to take advantage of all that earlier work? or is there more
> to it? it seems like a simple enough request, but i don't see it
> explained in the SDK manual.
> 
>   thoughts?

When you say "building an image", what are you building the image with? Are you
wanting OE to build the image with the external toolchain from the SDK? That is
a really bad idea.

Isn't sstate the answer to this question? Even say a set of locked down
signatures for the toolchain pieces?

Cheers,

Richard