The `sheevaplug` kernel configuration was added a very long time
ago and has not been adjusted for years. `pogoplug4` was identical
to `sheevaplug` except for an even more stripped‐down kernel
configuration, no device tree support, and a different load address
for the uImage.
These days, the stock kernel configuration builds and there has been
an upstream device tree for the Pogoplug Series 4 for years; unify
`sheevaplug` and `pogoplug4` into an `armv5tel-multiplatform` that
uses the standard configuration.
ARMv5 was also the only platform that defaulted to uImage, the [legacy
U‐Boot image format] that is deprecated upstream. Our bootloader
machinery in NixOS does not handle these images in any special way
and even the original ARMv6 Raspberry Pi platform defaults to the
standard zImage. We switch `armv5tel-multiplatform` to zImage to match.
[legacy U‐Boot image format]: https://docs.u-boot.org/en/latest/usage/cmd/bootm.html#legacy-boot
It is of course natural to worry about backwards compatibility
here: this switches to a different kernel image format and drops
support for root on NFS along with random oddities like KGDB and
LatencyTOP. Renaming the platform is intended to help mitigate
this risk.
The reality, however, is that it is currently very
difficult to build a configuration for ARMv5. I found
<https://github.com/thefloweringash/sheevaplug-nix> online as
an example configuration from many years ago; it already set
`autoModules`, and builds U‐Boot using `CONFIG_DISTRO_DEFAULTS`,
which should work out of the box without requiring the legacy U‐Boot
image format.
Even then, however, I confirmed with the author that it hasn’t
been used in years, and I could barely get it to build with
a modern Nixpkgs: OpenSSH is broken, Nix is broken, multiple
default `environment.systemPackages` in the SD image profile
are broken, `boot.initrd.includeDefaultModules` is broken, and
`hardware.enableAllHardware` is broken.
I conclude that if anyone is actively building systems on ARMv5, they
have a forked Nixpkgs or a very custom setup. Given our general move
to standard boot chains and no platform‐specific hacks, and the
decaying state of our unofficial support for 32‐bit ARM, I think
it is not worth maintaining support for the legacy image format for
this one ancient platform.
If anyone is running a heavily stripped‐down NixOS configuration on
mission‐critical SheevaPlugs using a custom Nix‐free deployment
setup relying on the legacy U‐Boot image format and somehow none
of these kernel changes manage to loudly break their build, hopefully
they’ll at least notice the release notes entry! Otherwise there’s
always JTAG…
After final improvements to the official formatter implementation,
this commit now performs the first treewide reformat of Nix files using it.
This is part of the implementation of RFC 166.
Only "inactive" files are reformatted, meaning only files that
aren't being touched by any PR with activity in the past 2 months.
This is to avoid conflicts for PRs that might soon be merged.
Later we can do a full treewide reformat to get the rest,
which should not cause as many conflicts.
A CI check has already been running for some time to ensure that new and
already-formatted files are formatted, so the files being reformatted here
should also stay formatted.
This commit was automatically created and can be verified using
nix-build a08b3a4d19.tar.gz \
--argstr baseRev b32a094368
result/bin/apply-formatting $NIXPKGS_PATH
In 5643714dea, I changed pkgs/stdenv/linux/make-bootstrap-tools.nix
to take a package set instead of system and localSystem arguments, but
I forgot to update make-bootstrap-tools-cross.nix.
Fixes: 5643714dea ("stdenvBootstrapTools: inherit {cross,local}System")
These servers apparently no longer exist, since September 2, 2021[1].
If somebody needs this for non-Scaleway machines, they should suggest
its reintroduction with a different name.
[1]: https://news.ycombinator.com/item?id=27192757
MIPS has a large space of {architecture,abi,endianness}; this commit
adds all of them to lib/systems/platforms.nix so we can be done with
it.
Currently lib/systems/inspect.nix has a single "isMips" predicate,
which is a bit ambiguous now that we will have both mips32 and mips64
support, with the latter having two ABIs. Let's add four new
predicates (isMips32, isMips64, isMips64n32, and isMips64n64) and
treat the now-ambiguous isMips as deprecated in favor of the
more-specific predicates. These predicates are used mainly for
enabling/disabling target-specific workarounds, and it is extremely
rare that a platform-specific workaround is needed, and both mips32
and mips64 need exactly the same workaround.
The separate predicates (isMips64n32 and isMips64n64) for ABI
distinctions are, unfortunately, useful. Boost's user-scheduled
threading (used by nix) does does not currently supports mips64n32,
which is a very desirable ABI on routers since they rarely have
more than 2**32 bytes of DRAM.
`pkgsNoParams` was removed by me, but then #25035 was merged using it,
leading to an unbound identifier.
It would be nice to get travis to do build release-cross.nix or
something to catch these things.
Use `buildPackages.binutils` to get build = host != target binutils,
i.e. the old `binutilsCross`, and use
`buildPackages.buildPackages.binutils` to get build = host = target
binutils, i.e. the old `binutils`.
`buildPackages` chains like this are supposed to remove the need for
all such `*Cross` derivations. We start with binutils because it's
comparatively easy.
No hashes of cross-tests should be changed
[N.B., this package also applies to the commits that follow it in the same
PR.]
In most cases, buildPackages = pkgs so things work just as before. For
cross compiling, however, buildPackages is resolved as the previous
bootstrapping stage. This allows us to avoid the mkDerivation hacks cross
compiling currently uses today.
To avoid a massive refactor, callPackage will splice together both package
sets. Again to avoid churn, it uses the old `nativeDrv` vs `crossDrv` to do
so. So now, whether cross compiling or not, packages with get a `nativeDrv`
and `crossDrv`---in the non-cross-compiling case they are simply the same
derivation. This is good because it reduces the divergence between the
cross and non-cross dataflow. See `pkgs/top-level/splice.nix` for a comment
along the lines of the preceding paragraph, and the code that does this
splicing.
Also, `forceNativeDrv` is replaced with `forceNativePackages`. The latter
resolves `pkgs` unless the host platform is different from the build
platform, in which case it resolves to `buildPackages`. Note that the
target platform is not important here---it will not prevent
`forcedNativePackages` from resolving to `pkgs`.
--------
Temporarily, we make preserve some dubious decisions in the name of preserving
hashes:
Most importantly, we don't distinguish between "host" and "target" in the
autoconf sense. This leads to the proliferation of *Cross derivations
currently used. What we ought to is resolve native deps of the cross "build
packages" (build = host != target) package set against the "vanilla
packages" (build = host = target) package set. Instead, "build packages"
uses itself, with (informally) target != build in all cases.
This is wrong because it violates the "sliding window" principle of
bootstrapping stages that shifting the platform triple of one stage to the
left coincides with the next stage's platform triple. Only because we don't
explicitly distinguish between "host" and "target" does it appear that the
"sliding window" principle is preserved--indeed it is over the reductionary
"platform double" of just "build" and "host/target".
Additionally, we build libc, libgcc, etc in the same stage as the compilers
themselves, which is wrong because they are used at runtime, not build
time. Fixing this is somewhat subtle, and the solution and problem will be
better explained in the commit that does fix it.
Commits after this will solve both these issues, at the expense of breaking
cross hashes. Native hashes won't be broken, thankfully.
--------
Did the temporary ugliness pan out? Of the packages that currently build in
`release-cross.nix`, the only ones that have their hash changed are
`*.gcc.crossDrv` and `bootstrapTools.*.coreutilsMinimal`. In both cases I
think it doesn't matter.
1. GCC when doing a `build = host = target = foreign` build (maximally
cross), still defines environment variables like `CPATH`[1] with
packages. This seems assuredly wrong because whether gcc dynamically
links those, or the programs built by gcc dynamically link those---I
have no idea which case is reality---they should be foreign. Therefore,
in all likelihood, I just made the gcc less broken.
2. Coreutils (ab)used the old cross-compiling infrastructure to depend on
a native version of itself. When coreutils was overwritten to be built
with fewer features, the native version it used would also be
overwritten because the binding was tight. Now it uses the much looser
`BuildPackages.coreutils` which is just fine as a richer build dep
doesn't cause any problems and avoids a rebuild.
So, in conclusion I'd say the conservatism payed off. Onward to actually
raking the muck in the next PR!
[1]: https://gcc.gnu.org/onlinedocs/gcc/Environment-Variables.html
I broke this in the cleanups I did in 171c7f0, the gcc inside the bootstrap
tarball is not getting built with the correct --with-fpu, --with-float
etc. options.
