build: Inline kernel building as a buildtime task

Kernel image integration is now done in the build system. The
"one true way" of doing this is to download the kernel source
into kernel/TARGET_BOOTLOADER_NAME (by usage of the cm.dependencies
mechanism or otherwise), and defining the TARGET_KERNEL_CONFIG
variable in the device's BoardConfig makefile

If the kernel's location doesn't match the automagic location
(multi-device kernel source, for instance), TARGET_KERNEL_SOURCE
can be used to specify a kernel path (i.e.,
"TARGET_KERNEL_SOURCE := kernel/shared-whatever")

If the device requires out-of-kernel-tree modules to be built,
the TARGET_KERNEL_MODULES variable can be used, pointing to a
_make target_ that will build and install such modules. Definition
of such a target is the device author's responsibility, the only
restriction is that it is a normal makefile recipe (example
below)

Optionally (or as an alternative), a prebuilt binary can also be
defined at BoardConfig, by usage of the TARGET_PREBUILT_KERNEL
variable. This binary will be used if the kernel source is absent
(or undefined).

A minimal BoardConfig.mk should look something like this:

TARGET_KERNEL_CONFIG := cyanogenmod_<device>_defconfig
TARGET_PREBUILT_KERNEL := device/<vendor>/<device>/kernel

To include, for example, the TI WLAN modules, this can be used:

-----------------------------
TIWLAN_MODULES:
       make -C hardware/ti/wlan/wl1283/platforms/os/linux/ KERNEL_DIR=$(KERNEL_OUT) ARCH="arm" CROSS_COMPILE="arm-eabi-" TNETW=1273 RANDOM_MAC=n REPORT_LOG=n
       mv hardware/ti/wlan/wl1283/platforms/os/linux/tiwlan_drv.ko $(KERNEL_MODULES_OUT)
       make -C hardware/ti/wlan/wl1283_softAP/platforms/os/linux/ KERNEL_DIR=$(KERNEL_OUT) ARCH="arm" CROSS_COMPILE="arm-eabi-" TNETW=1273 REPORT_LOG=n
       mv hardware/ti/wlan/wl1283_softAP/platforms/os/linux/tiap_drv.ko $(KERNEL_MODULES_OUT)

TARGET_KERNEL_MODULES := TIWLAN_MODULES
---------------------------

Change-Id: I8634fa4c788a42dc6f62e62ca170825b66db126a

build: Fix kernel module building on Darwin/OSX

Darwin/OSX build host does not have module-init-tools which is
required to generated modules.dep file. Switch to modules.order
file marker which is always generated instead.

Change-Id: I20c0fccd905fa668202c3e7284a8778db3728a65

kernel: Change path to kernel/<vendor>/<device>

Derive the kernel path from the device's own path (just replace "device"
with "kernel")

Change-Id: Idd44a0489e1ce280adf5ec4d9cfe2385c75dd115

kernel: Improve support for non-arm architectures

Remove hardwired references to the ARM arch and toolchains, and replace
them with the respective android build variables

Change-Id: Iae3eb548ca1d58ac808b5fa430d415283a809106

kernel: Fix ARM building

The default android ARM compiler, arm-androideabi-, does NOT work
for the Linux kernel. Special-case the ARM architecture to target
the ARM_EABI_TOOLCHAIN path directly

Change-Id: Ib672c99f114cb89d5fda3343d4dc68810d042d35

kernel: allow TARGET_KERNEL_MODULES to overwrite kernel modules

This is necessary to use compat-wireless since it needs to build a newer
version of cfg80211 (and sometimes mac80211) than the kernel sources version.
There are probably other instances of this type of need.

Change-Id: Ib5bf818286bc20987d8b9f9480a43f3e7690e239

kernel.mk: make use of ccache when requested

Change-Id: I9b6e28711bd5f590a76ac2b62a50b1d2de014e3e

kernel: Fix ccache inclusion logic

Builds were broken when CCACHE was missing from the environment
Change-Id: Ie8d6048f4600f1dc9c298593a50e37af04b96438

build: show accurate information on inline kernel warnings/errors

Having the variables on AndroidBoard as suggested causes errors
with mm/mmm, whereas having them on BoardConfig doesn't. Adjust
the warnings to reflect this.

Change-Id: I554c1f1073df678d36521f73bc236a1f4b02212e

This is causing generic_armv5-userdebug builds to fail. Commenting out for now to fix recovery build servers. Will fix properly later.

Change-Id: Ibe1cda8cd2b4c1914dfa3b8a29724c9069e047a6

kernel.mk: Also search PRODUCT_COPY_FILES for the kernel copy, as that is how AOSP does it now.

Change-Id: Id2d1cf079694d1996d4a85d8435c2e4562e5d444

kernel.mk: fix compiled kernel copy

Change-Id: Ifb2a3d4968e56eed236eaa2db9258cd0b8865fda

kernel.mk: workaround to fix kernel builds on darwin until the prebuilts/gcc is checked in by upstream.

Change-Id: I6321fb7f6814b207c821d974766d945351b3f546

build: fix ccache usage when building kernels

Change-Id: Id4edd4d85d9ba3ef42575f5fdebf22ed14957a99

kernel.mk: set KERNEL_OUT properly

It was hardcoded to $(ANDROID_BUILD_TOP)/$(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ
which wouldn't exist if OUT_DIR_COMMON_BASE was set to use another dir
(e.g. ramdisk)

Fix it so that it now points to $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ
if OUT_DIR is not out

Change-Id: I1bf767d86548e41270d9cbb8f0c00512708501c5

build: add support for uncompressed kernels

build: kernel: remove hard coded darwin toolchain.

* Use latest kernel toolchain from $(ARM_EABI_TOOLCHAIN) variable.

Change-Id: I3b43408937dd5f193fcba19c034f868272de8963

envsetup: set OUT_DIR to an absolute path always

OUT_DIR was set to $(TOPDIR)out previously,
but $(TOPDIR) was null, so it was a relative path.
This broke releasetools, inline kernel building, etc
since they require absolute paths.
Fix it so that it is set to $(shell readlink -f .)/out
if $(TOPDIR) is null.

Also remove hacks which checked if (OUT_DIR) was out
and changed it to $(ANDROID_BUILD_TOP)/out to workaround
the aforementioned problem.

Change-Id: I459a3b1325a1bbea0565cd73f6acf160d4ed9b39

build: add strip on kernel modules

kernel modules are huge for prima wlan and we need to strip them
unstriped size 40mb
striped size 2mb

Change-Id: Iefd572732cad0a6f608439618673068a3586fcd5

kernel: Ignore errors with module building

Let kernel fully disable loadable modules

Change-Id: Ia37ec927b092c041ee4c68bf9fd0f28b7339c8ca

build: Add support for extra kernel build variables

 * This allows specifying a variant defconfig, and an selinux defconfig
   which are simply configuration fragments.

Change-Id: I97882ae3b8c2e16ff6a7dce8dd3a70d70f8aa866

s/cyanogenmod.com/cyanogenmod.org/

* And fixup a wiki link while I'm at it.

Change-Id: I0355b9a47eac1becc07e81659fbb2d11b14ece36

Fixes for Xcode 5 and OSX 10.9.
kernel.mk: Put elf.h into the include path on Darwin builds.

Change-Id: I7069b956965d27caac3b2e4c3cc2e8b4c1da7a82

Make the kernel image format parametric instead of a chain of if/elses

Change-Id: I54bfcdecb8647f7bcf744e72b2de19fcf4e4e7ac

build: Add "dtbs" target when building the kernel

 * This is needed for 3.10

Change-Id: I4044ea9e67017452efc25097a3327141a6627c24
build: use the system's ccache by default

ccache 3.x supports direct mode (http://ccache.samba.org/manual.html#_the_direct_mode)
This is not supported in the prebuilt version.
Direct mode has been shown to decrease build time compared to the ccache in prebuilts

Note: this will require your cache to be recreated

PS3:
  make it so you need to export USE_SYSTEM_CCACHE=1 to use system ccache
  allow custom CCACHE_BASEDIR
oldChange-Id: Ib146011a3330637c2d306d329fcb39cea058ff12

Change-Id: I04491c8c603be2069ade181f498f5e9c1f408cc8