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| author | David 'Digit' Turner <digit@android.com> | 2011-06-15 15:33:24 +0200 |
|---|---|---|
| committer | David 'Digit' Turner <digit@google.com> | 2011-07-07 23:46:50 +0200 |
| commit | c7e3877dad2333bfdf41e99470d559f381431d3c (patch) | |
| tree | 4fed856723fff7404c853f6b5f08088ec78152e4 | |
| parent | 63152fd929265b73195492e64b29352e1d068287 (diff) | |
| download | build-c7e3877dad2333bfdf41e99470d559f381431d3c.tar.gz | |
emulator: Build emulator platform images as ARMv7-A
Backport from AOSP master.
Now that the emulator supports proper ARMv7 emulation, switch to
building all emulator-specific platform images using this instruction
set, in order to benefit from the noticeable speed boost provided by
Thumb-2 instructions.
Note that we don't build with NEON support because emulated NEON
instructions are currently slow, though they work.
IMPORTANT: You need to have the following emulator patch in your tree
in order to start these platform builds easily:
https://review.source.android.com//#change,23798
Otherwise, the alternative is to do these things:
1/ Telling the emulator to emulate an ARMv7-A CPU, instead of
an ARMv5TE one. This is normally done with "-qemu cortex-a8"
2/ Using an ARMv7-A capable kernel image, which is available and
usable with -kernel prebuilt/android-arm/kernel-qemu-armv7
Note that the emulator has a special hack that automatically enables
1/ if 2/ is being used (i.e. if the kernel image name ends with -armv7,
then emulate an ARMv7-A CPU automatically).
So in reality, only 2/ is required.
Change-Id: Id3ac7cdbda892e519af98aff1f02136f344406b8
Orig-Change-Id: I5c0245ba5e6a2bc34d0d49b2c024fffd317a5eed
| -rw-r--r-- | target/board/generic/BoardConfig.mk | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/target/board/generic/BoardConfig.mk b/target/board/generic/BoardConfig.mk index 9e52d25c4d..1e8f9e49eb 100644 --- a/target/board/generic/BoardConfig.mk +++ b/target/board/generic/BoardConfig.mk @@ -6,7 +6,22 @@ # The generic product target doesn't have any hardware-specific pieces. TARGET_NO_BOOTLOADER := true TARGET_NO_KERNEL := true -TARGET_CPU_ABI := armeabi + +# Note: we build the platform images for ARMv7-A _without_ NEON. +# +# Technically, the emulator supports ARMv7-A _and_ NEON instructions, but +# emulated NEON code paths typically ends up 2x slower than the normal C code +# it is supposed to replace (unlike on real devices where it is 2x to 3x +# faster). +# +# What this means is that the platform image will not use NEON code paths +# that are slower to emulate. On the other hand, it is possible to emulate +# application code generated with the NDK that uses NEON in the emulator. +# +TARGET_ARCH_VARIANT := armv7-a +TARGET_CPU_ABI := armeabi-v7a +TARGET_CPU_ABI2 := armeabi + HAVE_HTC_AUDIO_DRIVER := true BOARD_USES_GENERIC_AUDIO := true |