Thanks a lot for sharing these! It seems a lot of efforts needed to cross-compiling OpenJDK (I do hope it could be easier :). A couple of more quick questions: 1) Is it same as OpenJDK 8? (I prefer 8 as it is the latest release, right?) 2) Is there any place that I can download prebuilt sysroot/rootfs? That would be great helpful. 3) Can you give me more hints on "bytecode generator tool" compilation? I'm not familiar with this..
Chen Long Xerxes Rånby <xer...@zafena.se>编写： > >Den 2014-12-09 10:27, Severin Gehwolf skrev: >> Hi, >> >> On Mon, 2014-12-08 at 21:46 +1000, David Holmes wrote: >>> On 8/12/2014 7:10 PM, ChenLong wrote: >>>> Hi >>>> >>>> Apologize if this is not the right place to ask. >>>> I want to try OpenJDK8 on Armv7. Is there a guideline on how to cross >>>> compile OpenJDK8 for Armv7? And if not, could someone share some >>>> experiences? I went through the README-builds.html and did not find any >>>> clues for cross compiling. >>> The only OpenJDK build for ARM would be a ZERO build. But I don't know >>> how to do Zero builds - though I'm sure the Zero folk will chime in. >> CC'ing zero-dev. > >when I cross-compile OpenJDK 9 for ARM32 I pass the following configure >options > >configure ># these options tell openjdk to do a cross compile build. >--build=x86_64-unknown-linux-gnu >--host=arm-buildroot-linux-gnueabi >--target=arm-buildroot-linux-gnueabi > ># these two options enable zero >--with-jvm-interpreter=cpp >--with-jvm-variants=zero > ># specific options to make the build find the X and freetype headers and >librarys found on the ARM32 root filesystem. >--disable-freetype-bundling >--with-freetype-include=/home/xranby/rpi-buildroot/output/host/usr/arm-buildroot-linux-gnueabi/sysroot/usr/include/freetype2 >--with-freetype-lib=/home/xranby/rpi-buildroot/output/host/usr/arm-buildroot-linux-gnueabi/sysroot/usr/lib >--with-freetype=/home/xranby/rpi-buildroot/output/host/usr/arm-buildroot-linux-gnueabi/sysroot/usr/ >--with-x=/home/xranby/rpi-buildroot/output/host/usr/arm-buildroot-linux-gnueabi/sysroot/usr/include > ># the sysroot shall point to the ARM32 root file system, the build will >use librarys inside the sys root during linking native libraries. >--with-sys-root=/home/xranby/rpi-buildroot/output/host/usr/arm-buildroot-linux-gnueabi/sysroot ># The tools dir contains binarys to run on the host x86 system, you may >point this to your system root dir / ># in my case the tools i use have been compiled by buildroot thus I use >the buildroot tools dir. >--with-tools-dir=/home/xranby/rpi-buildroot/output/host ># OpenJDK 9 require OpenJDK 8, i point with boot jdk to an OpenJDK 8 >image that can be run on the host x86 system. >--with-boot-jdk=/home/xranby/images-jdk8/j2sdk-image/ > ># some parts of the openjdk build still expect that the cross compile >tools are found in the system PATH ># on my system i have to explicitly tell where the tools are located >because my cross compile toolchain is not found on the path. ># i use gcc to do the linking instead of ld because the openjdk build >passes -Xlinker -z >OBJCOPY=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-objcopy >STRIP=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-strip >CPP=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-cpp >CXX=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-g++ >CC=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-gcc >LD=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-gcc >CPP_FLAGS=-lstdc++ >CXX_FLAGS=-lstdc++ > > >when running make i pass the following options to make ># BUILD_CC and BUILD_LD shall point to host x86 executables. >BUILD_CC=gcc >BUILD_LD=gcc >OBJCOPY=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-objcopy >STRIP=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-strip >CPP=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-cpp >CXX=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-g++ >CC=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-gcc >LD=/home/xranby/rpi-buildroot/output/host/usr/bin/arm-buildroot-linux-gnueabi-gcc >#and finally the target, this will build compact profiles, jre and jdk >images. >all images profiles CONF=linux-arm-normal-zero-release > > >I have automated these configure and make options for openjdk 9 into >buildroot build scripts >https://github.com/xranby/rpi-buildroot/tree/openjdk > >> >> I've done Zero builds before but have never used OpenJDK's cross-compile >> feature to build it on ARMv7. There is an Arm32 bit JIT in IcedTea[1], >> but I don't know if that can be cross-compiled. > >If you cross compile icedtea then you need to make sure that the >bytecode generator tool is compiled by the host x86 toolchain. >openembedded meta-java contains buildscripts that can cross compile the >Arm32 JIT found in IcedTea. >https://github.com/woglinde/meta-java > >Cheers >Xerxes > >> >> Cheers, >> Severin >> >> [1] >> http://blog.fuseyism.com/index.php/2014/03/28/icedtea-2-3-14-2-4-6-considered-armful-released/ >> >>> David >>> >>>> Thanks >>>> Chen Long >>>> >> >> >
