platforms.nix: Separate 32-bit and 64-bit PCs

With this, stdenv.platform.kernelArch can be used by the kernel builder
for PC platforms too.

Signed-off-by: Shea Levy <shea@shealevy.com>
linux/manual-config: Cross-compiling support

With this, I was able to successfully compile a defconfig kernel for the
sheevaplug, though I didn't actually try to run it (not having a
sheevaplug myself).

For native compiles, the most significant difference is that the
platform's kernel target is built directly rather than hoping the
default make target will pull it in.

Also some stylistic improvements along the way.

Signed-off-by: Shea Levy <shea@shealevy.com>
manual-config: Always add config query functions

If the config attrset is manually specified, we still want isYes,
isModule, etc. to work. But we let the passed in config attrset take
precedence, if for some reason the caller wants to provide their own
implementation of one or more of these functions.

Signed-off-by: Shea Levy <shea@shealevy.com>
manual-config: Patch conf.c for generate-config.pl

This only affects the `oldaskconfig' make target, so it shouldn't really
affect current manual-config users, but it does make it more
straightforward to implement the generic kernel build on top of
manual-config.

Signed-off-by: Shea Levy <shea@shealevy.com>
manual-config: Put `source' before the version in the sourceRoot name

nix's version parsing treats the previous name as a package named
`linux' with version `${version}-source', when we really want a package
named `linux-source' with version `${version}'

Signed-off-by: Shea Levy <shea@shealevy.com>
manual-config: Fully general cross-compiling

In the most general case, the cross and native kernel may differ in
patches and configuration file as well as architecture, kernel target,
etc. It's probably overkill to support that case, but since it was
doable without much duplication and it will make integrating with the
existing cross-compilation support in the generic kernel I decided to
implement it anyway.

Signed-off-by: Shea Levy <shea@shealevy.com>
Implement generic kernel build via manual-config

This has three major benefits:

1. We no longer have two kernel build processes to maintain

2. The build process is (IMO) cleaner and cleaves more closely to
upstream. In partuclar, we use make install to install the kernel and
development source/build trees, eliminating the guesswork about which
files to copy.

3. The derivation has multiple outputs: the kernel and modules are in
the default `out' output, while the build and source trees are in a
`dev' output. This makes it possible for the full source and build tree
to be kept (which is expected by out-of-tree modules) without bloating
the closure of the system derivation.

In addition, if a solution for how to handle queries in the presence of
imports from derivations ever makes it into nix, a framework for
querying the full configuration of the kernel in nix expressions is
already in place.

Signed-off-by: Shea Levy <shea@shealevy.com>
kernel build: limit dev output footprint

This makes the disk usage footprint of building the kernel smaller in 3
ways:

1) There is no separate kernel source derivation
2) Rather than using the entire build tree, only the output of make
modules_prepare is kept in the $dev output (plus the module symbol
versioning file generated during the build)
3) Only the subset of the source tree known to be needed for external
builds is kept in $dev

Note that while 2) is supported by official kernel documentation, I
couldn't find any source describing what we need to keep for 3). I've
started with the bare minimum (the main Makefile is called by the
Makefile generated by make modules_prepare) and we can/should add more
as needed for kernelPackages.

Signed-off-by: Shea Levy <shea@shealevy.com>
systemtap: Remove from linuxPackagesFor

It doesn't seem to depend on the kernel in any way.

Signed-off-by: Shea Levy <shea@shealevy.com>
Update and fix kernel packages to new kernel build

In most cases, this just meant changing kernelDev (now removed from
linuxPackagesFor) to kernel.dev. Some packages needed more work (though
whether that was because of my changes or because they were already
broken, I'm not sure). Specifics:

* psmouse-alps builds on 3.4 but not 3.10, as noted in the comments that
  were already there
* blcr builds on 3.4 but not 3.10, as noted in comments that were
  already there
* open-iscsi, ati-drivers, wis-go7007, and openafsClient don't build on
  3.4 or 3.10 on this branch or on master, so they're marked broken
* A version-specific kernelHeaders package was added

The following packages were removed:

* atheros/madwifi is superceded by official ath*k modules
* aufs is no longer used by any of our kernels
* broadcom-sta v6 (which was already packaged) replaces broadcom-sta
* exmap has not been updated since 2011 and doesn't build
* iscis-target has not been updated since 2010 and doesn't build
* iwlwifi is part of mainline now and doesn't build
* nivida-x11-legacy-96 hasn't been updated since 2008 and doesn't build

Everything not specifically mentioned above builds successfully on 3.10.
I haven't yet tested on 3.4, but will before opening a pull request.

Signed-off-by: Shea Levy <shea@shealevy.com>
Greatly reduce kernel closure size

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>
Merge branch 'merge-kernel-builds' into upstream-master

This is a second attempt at unifying the generic and manual-config
kernel builds (see #412 for the last time).

The set of working kernel packages is a superset of those that work on
master, and as the only objection last time was the size of the $dev
closure and now both $out and $dev combined are 20M smaller than $out on
master (see message for ac2035287fbec30d92165fd3839d1bf71b8edd47), this
should be unobjectionable.

Signed-off-by: Shea Levy <shea@shealevy.com>