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

Allow specifying kernel toolchain and prefix

Change-Id: Ib75cfe772e073f2196455f3e3dfba247f6b3feff

Fix libelf path

Fixes kernel build

Change-Id: Ic6cdb1734d7b865491e8e61403d32db4acafe514
Signed-off-by: Alvin Francis <nivlafx@gmail.com>

core: More flexible kernel configuration

 * Allow various combinations of kernel vs. userspace architectures
 * Get rid of various assumptions about everything being ARM or 32-bit
 * This adds the following target flags:
     TARGET_KERNEL_ARCH
     TARGET_KERNEL_HEADER_ARCH
     KERNEL_HEADER_DEFCONFIG
     TARGET_KERNEL_CROSS_COMPILE_PREFIX

Change-Id: If0bc202abd35c216ba3ea5707ffdb602526d8ed3

Fix kernel.mk if SELINUX or VARIANT_DEFCONFIG is defined

KERNEL_HEADER_DEFCONFIG was ignoring SELINUX_DEFCONFIG thus breaking
all selinux support

Change-Id: Idc3367d6b4b85343078e63e87dca6d6d052e7f53

build: kernel: Fix stray "@"

Nested "$(hide)"s (makefile @) don't work. There was one at the
beginning of the script, remove the inner one to prevent it from
being interpreted as a shell command

Change-Id: I08a829ee56b212366a0f5a3812f7a614667a9c2b

build: Add support for additional kernel config snippet

 * Add support for TARGET_KERNEL_ADDITIONAL_CONFIG which will append a
   config snippet from arch/$ARCH/configs/ to the main defconfig.
 * This can be used for various things, such as including DIAG support
   into debuggable builds.

Change-Id: Ifa48688a3f951dd8ecc9a13a27de3a476e7bf633

kernel: Fix kernelconfig build

* Copy the generated defconfig to the correct directory

Change-Id: Ia8e259946d67501675dd5a3433165d54df6c13c5

build: kernel: arm64 uses Image.gz as the target

Change-Id: Icc194d2a16f9ffcf5803226fc1f2a5b091b4d861

kernel: use merge-config.sh for integrating KERNEL_ADDITIONAL_CONFIG

Using 'cat' to combine defconfig fragments is not, in general,
safe. Overriding options is not correctly handled, and it's
possible to produce illegal configurations which violate Kconfig
dependency constraints.

Instead, use the merge-config.sh script from the kernel tree
which more intelligently combines defconfig fragments. An
'alldefconfig' make target is also introduced, as merge-config.sh
depends on it.

Change-Id: I91a8c5e4bcf7072a3f95651dffe17380174134e4

kernel: Don't update defconfig with KERNEL_ADDITIONAL_CONFIG options

If 'make kernelconfig' is run in an environment where
KERNEL_ADDITIONAL_CONFIG is set, the options in the additional
defconfig will be saved back to the defconfig when savedefconfig
is performed.

While not really a bug, this increases the likelihood of someone
accidentally committing these changes or getting confused by
unexpected deltas added to their defconfigs.

Fix this by skipping the merge-config.sh step for the 'kernelconfig'
make target. As a side-effect, options in KERNEL_ADDITIONAL_CONFIG
will also not be displayed in menuconfig. This is not easily
avoidable, and arguably not wrong anyway.

Change-Id: I920be0338bb8afc87f6061c55aafb27ba658974d

kernel: add `make kernelxconfig' target

kernelxconfig is identical to kernelconfig except that it launches
xconfig instead of menuconfig. xconfig easier to use if you need to
search the Kconfig tree.

Change-Id: I6d91c7e3efbc9f172b040425f2ec545e3f03b44d
(cherry picked from commit 60ca2b78)

kernel: don't build modules or dtbs unless enabled

Build modules and dtbs only if enabled. The make commands were allowed to
fail silently to support builds that did not have these options
enabled.

This had a side effect of allowing builds to complete even if modules
failed to build. Don't suppress these error anymore.

Change-Id: I842124b465d9e14edd6a09ffe54f09da32f10632

kernel: prevent targets from being rebuilt needlessly

Fix some rules that listed directories as their dependencies.
Directories are always out-of-date because the rules that depend on
them touch file under the directories they depend on them.

Replace the directory dependencies with stamp file rules that handle
directory creation.

Change-Id: I2b36c846b6565b7f9aba5bb7583576ad300983b8

kernel: Fix usage of KERNEL_ARCH

* x86_64 defconfigs live in arch/x86/configs
* Use KERNEL_ARCH instead of TARGET_KERNEL_ARCH

Change-Id: Idc191ea658fc4100bc7ad40958023c5f936daf44

build: force .config update if additional kernel config changes

This patch forces a regeneration of the .config if either the
contents of TARGET_KERNEL_ADDITIONAL_CONFIG changes or the value
of TARGET_KERNEL_ADDITIONAL_CONFIG changes.

OPO-360
Change-Id: Ide28be3fab01b9f9ad72aa9d8706131e2b9ac0c7

build: add build module from root

Zenfone 5 have copies module to root , we use it

Change-Id: I734e45a09d445e97f2b3834c5941db27e537b803

kernel: Don't use override config in kernel(x)config

* It defeats the whole purpose of using KERNEL_CONFIG_OVERRIDE

Change-Id: Ia405562a0dcf623ae2bfca2803c2d3427d84bf0a

kernel: remove support for unused MTK Kernel

Remove unused MTK kernel build support.

Change-Id: I4f4df078ae03b1bd5edc7000e5b942bfc05c02bd

kernel: add docs for config vars

Add a header with documentation for the config vars currently in use
by the Kernel build.

Change-Id: I6930b41d716baabbb16c2f407b6b9fe6e5f2b4c8

kernel: allow toolchain prefix to be overridden

Allow the toolchain prefix defined in BoardConfig.mk to be overridden
via by setting KERNEL_TOOLCHAIN_PREFIX (alongside KERNEL_TOOLCHAIN) to
compile with an alternate toolchain.

Change-Id: If6f4f0dba9bd0b0056f76e380070cca74ea0a4df

kernel: add banner for defconfig and header install steps

Change-Id: Iddf9e1e206823573ebc38a8956a029d08dee83de

build: Add dt.img and kernel target

Change-Id: I4a266d8bd2b01ec4ec696f10f0cc7e912f25a38a

Fix libelf path for mm

Fixes kernel build on darwin

Updated for cm-13.0

Change-Id: Ic6cdb1734d7b865491e8e61403d32db4acafe514
Signed-off-by: Alvin Francis <nivlafx@gmail.com>