This adds a warning to the top of each “boot” package that reads:
Note: this package is used for bootstrapping fetchurl, and thus cannot
use fetchpatch! All mutable patches (generated by GitHub or cgit) that
are needed here should be included directly in Nixpkgs as files.
This makes it clear to maintainer that they may need to treat this
package a little differently than others. Importantly, we can’t use
fetchpatch here due to using <nix/fetchurl.nix>. To avoid having stale
hashes, we need to include patches that are subject to changing
overtime (for instance, gitweb’s patches contain a version number at
the bottom).
This should make the composability of kernel configurations more straigthforward.
- now distinguish freeform options from tristate ones
- will look for a structured config in kernelPatches too
one can now access the structuredConfig from a kernel via linux_test.configfile.structuredConfig
in order to reinject it into another kernel, no need to rewrite the config from scratch
The following merge strategies are used in case of conflict:
-- freeform items must be equal or they conflict (mergeEqualOption)
-- for tristate (y/m/n) entries, I use the mergeAnswer strategy which takes the best available value, "best" being defined by the user (by default "y" > "m" > "n", e.g. if one entry is both marked "y" and "n", "y" wins)
-- if one item is both marked optional/mandatory, mandatory wins (mergeFalseByDefault)
Instead of using a string to describe kernel config, use a nix
attribute set, then converted to a string.
- allows to override the config, aka convert 'yes' into 'modules' or
vice-versa
- while for now merging different configs is still crude (last spec wins),
at least there should be only one CONFIG_XYZ value compared to the current string
config where the first defined would be used and others ignored.
[initial idea by copumpkin in 2016, a major rebase to 2018 by teto]
common-config.nix has:
${kernelPlatform.kernelExtraConfig or ""}
and indeed kernelExtraConfig is in hostPlatform.platform, and not in
hostPlatform. (Ugh.).
- defined buildLinux as generic.nix instead of manual-config.nix. This
makes kernel derivations a tad more similar to your typical derivations.
- moved $buildRoot to within the source folder, this way it doesn't have to be created before the unpackPhase
and make it easier to work on kernel source without running the unpackPhase
For a while now, the only thing the 'uboot' attribute does is to tell
whether to add ubootTools to kernel/initrd builds. That can be
determined with platform.kernelTarget == "uImage" just as well.
This allows to use kernelAutoModules but still compile in any options that are set so in template config.
It's helpful for ARM and maybe other platforms where defaul configurations are useful because they compile in
modules that we and udev cannot autodetect now.
Testing showed the linux build is sensitive to /usr/include/ncursesw
unless chrooted (on non-nixos).
On a single chrooted nixos machine, -A linux is binary reproducible.
CC #2281 & @alexanderkjeldaas.
Based on access analysis with strace, I determined an essentially
minimal required set of files from the kernel source that was needed to
build all current kernel packages on 3.10, which ultimately resulted in
keeping 30M of source. Generalizing from that minimal set, which
required ad-hoc specifications of which headers outside of include/ and
arch/*/include and which files in the scripts/ directory should be kept,
to a policy of keeping all non-arch-specific headers that aren't part of
the drivers/ directory and the entire scripts/ directory added an
additional 17M, but there was nothing in the analysis that indicated
that that ad-hoc specification was at all complete so I think the extra
hit is worth the likely greater compatibility.
For reference, we now keep:
* All headers that are NOT in arch/${notTargetArch}/include or drivers/
* The scripts/ directory
* Makefile
* arch/${targetArch}/Makefile
IMO the most likely cause of future problems are the headers in
drivers/, but hopefully they won't actually be needed as they add 50M
Ideally kernel packages would only use include and
arch/${targetArch}/include, but alas this is observably not the case.
master:
* $out
* size: 234M
* references-closure: linux-headers, glibc, attr, acl, zlib, gcc,
coreutils, perl, bash
merge-kernel-builds:
* $out
* size: 152M
* references-closure: none
* $dev
* size: 57M
* references-closure: linux-headers, glibc, zlib, gcc
So even with the non-minimal set we still beat out master. Keeping the
drivers headers would make us only slightly bigger.
Signed-off-by: Shea Levy <shea@shealevy.com>
