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howtos:hardware:arm:gcc-9.x_aarch64_cross-compiler [2019/07/25 19:33 (UTC)]
exaga [Downloading required source and configuration] additional notes |
howtos:hardware:arm:gcc-9.x_aarch64_cross-compiler [2019/08/03 12:46 (UTC)]
exaga [Building the gcc aarch64 cross-compiler] missing CFLAG |
| === Preface === | === Preface === |
| |
| With the recent congruous updates to [[http://arm.slackware.com|Slackware ARM]] [~24 June 2019 - "A MILLION THANKS to MoZes!"] and the surprise arrival of the Raspberry Pi 4, this just had to be done. Creating a gcc-9.1.0 armv8 arm64 aarch64 cross-compiler with the intention of building aarch64-linux binaries from source code and turning them into Slackware packages. | With the recent congruous updates to [[http://arm.slackware.com|Slackware ARM]] [~24 June 2019 - "A MILLION THANKS to MoZes!"] and the surprise arrival of the Raspberry Pi 4, this just had to be done. Creating a 64-bit gcc-9.1.0 arm64 aarch64 cross-compiler with the intention of building aarch64-linux binaries from source code and turning them into Slackware packages. |
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| Previous [[howtos:hardware:arm:gcc_aarch64_cross-compiler|work in this area]] had already been done in 2016/2017. However, this time we'll be compiling with gcc-9.1.0 and not gcc-5.4.0 and we'll be using a Raspberry Pi 4 Model B and not a Mk3 version. The old build scripts weren't totally useless and some of the code was reused for this project, to save time. | Previous [[howtos:hardware:arm:gcc_aarch64_cross-compiler|work in this area]] had already been done since 2016/2017. However, this time we'll be compiling with gcc-9.1.0 and not gcc-5.4.0 and we'll be using a Raspberry Pi 4 Model B and not a Mk3 version. The old build scripts weren't totally useless and some of the code was reused for this project, to save time. |
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| === Notes === | === Notes === |
| When that's done you should see a message that 'origin/rpi-5.2.y' is the current branch. | When that's done you should see a message that 'origin/rpi-5.2.y' is the current branch. |
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| <note tip>You can select which kernel source you would like to build instead of rpi-5.2.y branch. Just substitute it in the 'git checkout -f rpi-5.2.y' command for your chosen branch. To see a list of available branches use this command while in your Linux source directoy: | <note tip>You can select which kernel source you would like to build instead of rpi-5.2.y branch. Just substitute it in the 'git checkout -f rpi-5.2.y' command for your chosen branch. To see a list of available branches use this command while in your Linux source directory: |
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| <code> | <code> |
| === Building binutils === | === Building binutils === |
| |
| First move back into the 'BUILD' directory and then create a build directory for binutils. You'll notice the various build options but as a quick explanation; '--with-sysroot' basically tells binutils to enable 'sysroot' support in the cross-compiler by pointing it to a default empty directory, '--target=aarch64-linux' is the target system type (arm64), and '--disable-multilib' means that we only want binutils to work with the aarch64 instruction set and nothing else. | First move back into the 'BUILD' directory and then create a build directory for binutils. You'll notice the various CFLAGS but as a quick explanation; '--with-sysroot' basically tells binutils to enable 'sysroot' support in the cross-compiler by pointing it to a default empty directory, '--target=aarch64-linux' is the target system type (arm64), and '--disable-multilib' means that we only want binutils to work with the aarch64 instruction set and nothing else. |
| |
| <code> | <code> |
| mkdir build-binutils | mkdir build-binutils |
| cd build-binutils | cd build-binutils |
| ../binutils-2.32/configure --prefix=/tmp/.gcc-cross --target=aarch64-linux --disable-multilib | ../binutils-2.32/configure --prefix=/tmp/.gcc-cross --target=aarch64-linux --with-sysroot --disable-multilib |
| make -j4 | make -j4 |
| make install | make install |
| ==== Building the arm64 kernel, modules, and device tree blob (DTB) ==== | ==== Building the arm64 kernel, modules, and device tree blob (DTB) ==== |
| |
| To build the aarch64 kernel, modules and device tree blob(s) is exactly the same method as you would carry it out under normal circumstances. Commands such as 'make bzImage && make modules && make modules_install' may be all too familiar to you. The major difference when cross-compiling is that you'll use certain Makefile options/variables/arguments/switches, commonly known as CFLAGS. In our case, CFLAGS will be used to instruct the gcc cross-compiler to build for the aarch64 (arm64) architecture specifically. | To build the aarch64 kernel, modules and device tree blob(s) is exactly the same method as you would carry it out under normal circumstances. Commands such as 'make bzImage && make modules && make modules_install' may be all too familiar to you. The major difference when cross-compiling is that you'll use certain Makefile variables/arguments/switches, commonly known as //build options//<. In our case, //build options// will be used to instruct the gcc cross-compiler to build for the aarch64 (arm64) architecture specifically. |
| |
| === Creating the arm64 kernel .config === | === Creating the arm64 kernel .config === |
| </code> | </code> |
| |
| <note important>Make a note here of the CFLAGS which have been specified. They should be self-explanatory by now. Pay special attention to the trailing '-' of 'CROSS_COMPILE=aarch64-linux-' because that's **NOT** a typo. __It needs to be like that!__</note> | <note important>Make a note here of the //build options// [ARCH=arm64 CROSS_COMPILE=aarch64-linux-] which have been specified. They should be self-explanatory by now. Pay special attention to the trailing '-' of 'CROSS_COMPILE=aarch64-linux-' because that's **NOT** a typo. __It needs to be like that!__</note> |
| |
| Now that you've created a kernel .config which contains the default settings for your hardware, some settings within need to be checked and possibly modified. The Raspberry Pi 4's "VideoCore VI" GPU is not //64-bit compatible// and the build process will crash each time you attempt to compile the module's source code for ARMv8 architecture. | Now that you've created a kernel .config which contains the default settings for your hardware, some settings within need to be checked and possibly modified. The Raspberry Pi 4's "VideoCore VI" GPU is not //64-bit compatible// and the build process will crash each time you attempt to compile the module's source code for ARMv8 architecture. |
| === Building the arm64 kernel === | === Building the arm64 kernel === |
| |
| Next up is building the kernel, based on the .config file you have just created. Again, you'll use the same CFLAGS as before. You can even set a 'LOCALVERSION' here which appends whatever you set to the end of the kernel version (e.g. LOCALVERSION="-aarch64" would eventually give you 5.2.1-v8-aarch64) once the kernel and modules have been built. Just as an example we'll use it here. Run the following command to start building the arm64 Linux kernel: | Next up is building the kernel, based on the .config file you have just created. Again, you'll use the same //build options// as before. You can even set a 'LOCALVERSION' here which appends whatever you set to the end of the kernel version (e.g. LOCALVERSION="-aarch64" would eventually give you 5.2.1-v8-aarch64) once the kernel and modules have been built. Just as an example we'll use it here. Run the following command to start building the arm64 Linux kernel: |
| |
| <code> | <code> |
| === Installing the arm64 modules === | === Installing the arm64 modules === |
| |
| Once the modules have been built, you have to 'make modules_install'. The process will install your kernel modules to '/tmp/lib/modules/5.2.1-v8-aarch64'. | Once the modules have been built, you have to 'make modules_install'. The process will install your kernel modules to '/lib/modules/5.2.1-v8-aarch64'. |
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| You could build //out-of-tree// kernel modules but, to keep things simple, you're going to install them to the usual location. Again, you will use the same CFLAGS as before but without any 'LOCALVERSION' set. | You could build //out-of-tree// kernel modules but, to keep things simple, you're going to install them to the usual location. Again, you will use the same //build options// as before but without any 'LOCALVERSION' set. |
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| First you need become '**root**' user and enter a passwd when prompted. To install the aarch64 modules run the following commands: | First you need become '**root**' user and enter a passwd when prompted. To install the aarch64 modules run the following commands: |
| <code> | <code> |
| ls -lah rpi-boot/boot/kernel* | ls -lah rpi-boot/boot/kernel* |
| ls -lah rpi-boot/boot/bcm*-rpi-3-b.dtb | ls -lah rpi-boot/boot/bcm*-rpi-4-b.dtb |
| ls -lah rpi-root/lib/modules/5.2.1-v8* | ls -lah rpi-root/lib/modules/5.2.1-v8* |
| </code> | </code> |
| |
| ====== Sources ====== | ====== Sources ====== |
| # If you need to install any of the packages above [* check for updates!]: | # If you need to install any of the software above [* check for updates!]: |
| |
| [[ftp://ftp.arm.slackware.com/slackwarearm/slackwarearm-current/slackware/a/gawk-5.0.1-arm-1.txz]] # Slackware ARM current - gawk package. \\ | [[ftp://ftp.arm.slackware.com/slackwarearm/slackwarearm-current/slackware/a/gawk-5.0.1-arm-1.txz]] # Slackware ARM current - gawk package. \\ |
| [[slackwarearm:faq|http://arm.slackware.com/FAQs]] # Slackware ARM Linux Project Frequently Asked Questions. \\ | [[slackwarearm:faq|http://arm.slackware.com/FAQs]] # Slackware ARM Linux Project Frequently Asked Questions. \\ |
| [[http://wiki.osdev.org/GCC_Cross-Compiler]] # gcc cross-compiler documentation. \\ | [[http://wiki.osdev.org/GCC_Cross-Compiler]] # gcc cross-compiler documentation. \\ |
| | [[howtos:hardware:arm:gcc_aarch64_cross-compiler|Slackware ARM GCC aarch64-linux cross-compiler]] for the Raspberry Pi. \\ |
| [[https://www.raspberrypi.org/documentation/linux/kernel]] # Raspberry Pi Linux kernel documentation. \\ | [[https://www.raspberrypi.org/documentation/linux/kernel]] # Raspberry Pi Linux kernel documentation. \\ |
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