## ¿What is a cross compiler? ------ ![a bridge crossing the ocean](https://images6.alphacoders.com/480/thumb-1920-480025.jpg) First of all a *compiler* is a computer software that translate one *programming language* to another. To be more exact, it normally translate a **high level** source programming language code to a **low level** one. For example the `gcc` compiler translate `C` source code in `asm` (**assembler**) machine code. A *cross compiler* is a compiler that generete machine code for a different *architecture* respect the one where the compiler is executed. The example that we will explain in this guide is **from x64 intel processor to a quad-core ARM Cortex A53 (ARMv8) cluster, classificated under the arm64 family**. ## Gentoo cross compiling environment ------ ![gentoo penguin](https://c402277.ssl.cf1.rackcdn.com/photos/1560/images/story_full_width/HI_292876WHYMatter1.jpg?1345547525) [The Gentoo Linux distribution](https://www.gentoo.org) have got a script package that simplify the life of a *system administrator* speaking about the work of preparing the correct *cross compiler environment*. Its name is [**crossdev**](https://packages.gentoo.org/packages/sys-devel/crossdev). These are the steps to obtain a working `arm64` compile environment. First of all we `emerge` the package using the options: - `-a` Before performing the action, display what will take place then ask whether to proceed with the action or abort. Using --ask is more efficient than using --pretend and then exe‐ cuting the same command without --pretend, as dependencies will only need to be calculated once. - `-v` Tell emerge to run in verbose mode. ```sh cyberdream /home/taglio # emerge -av crossdev These are the packages that would be merged, in order: Calculating dependencies... done! [ebuild N ] sys-devel/crossdev-20171230::gentoo 23 KiB Total: 1 package (1 new), Size of downloads: 23 KiB Would you like to merge these packages? [Yes/No] Yes >>> Verifying ebuild manifests >>> Emerging (1 of 1) sys-devel/crossdev-20171230::gentoo >>> Installing (1 of 1) sys-devel/crossdev-20171230::gentoo >>> Recording sys-devel/crossdev in "world" favorites file... >>> Jobs: 1 of 1 complete Load avg: 0.67, 0.55, 0.29 * Messages for package sys-devel/crossdev-20171230: * Package: sys-devel/crossdev-20171230 * Repository: gentoo * Maintainer: crossdev@gentoo.org embedded@gentoo.org * USE: abi_x86_64 amd64 elibc_glibc kernel_linux userland_GNU * FEATURES: preserve-libs sandbox userpriv usersandbox * Final size of build directory: 196 KiB * Final size of installed tree: 204 KiB >>> Auto-cleaning packages... >>> No outdated packages were found on your system. * GNU info directory index is up-to-date. cyberdream /home/taglio # ``` Next we've got to configure an [**overlay **](https://wiki.gentoo.org/wiki/Project:Overlays/Overlays_guide) to use with `crossdev`. - Make correct tree directories using the [**Gentoo portage**](https://wiki.gentoo.org/wiki/Portage) instructions. ```bash cyberdream /usr/local # mkdir -pv /usr/local/portage-crossdev/{profiles,metadata} mkdir: created directory '/usr/local/portage-crossdev' mkdir: created directory '/usr/local/portage-crossdev/profiles' mkdir: created directory '/usr/local/portage-crossdev/metadata' cyberdream /usr/local # echo 'crossdev' > /usr/local/portage-crossdev/profiles/repo_name cyberdream /usr/local # echo 'masters = gentoo' > /usr/local/portage-crossdev/metadata/layout.conf cyberdream /usr/local # chown -R portage:portage /usr/local/portage-crossdev cyberdream /usr/local # cat << EOF > /etc/portage/repos.conf/crossdev.conf [crossdev] location = /usr/local/portage-crossdev priority = 10 masters = gentoo auto-sync = no EOF cyberdream /usr/local # ``` Now we're going to build the **toolchain** for the `arm64` architecture using the **stable branch** tools. Those are the options used: - `--stable` Use latest stable tools version as default. - `-t` Choose an architecture between: - [alpha](https://en.wikipedia.org/wiki/DEC_Alpha) - [hppa (parisc)](https://en.wikipedia.org/wiki/PA-RISC) - [i386 / i486 / i586 / i686 (x86)](https://en.wikipedia.org/wiki/X86) *32 bit version* - [mips / mipsel / mips64 / mips64el](https://en.wikipedia.org/wiki/MIPS_architecture) - [powerpc (ppc) / powerpc64 (ppc64)](https://en.wikipedia.org/wiki/PowerPC) - [sparc / sparc64](https://en.wikipedia.org/wiki/SPARC) - [sh / sh[1-5] / sh64](https://en.wikipedia.org/wiki/SuperH) - [arm / armeb / aarch64](https://en.wikipedia.org/wiki/ARM_architecture) - [ia64](https://en.wikipedia.org/wiki/IA-64) - [m68k](https://en.wikipedia.org/wiki/Motorola_68000_series) - [s390 / s390x](https://en.wikipedia.org/wiki/Z/Architecture) - [x86_64 (amd64)](https://en.wikipedia.org/wiki/X86) *64 bit version* - `-genv` Specify environment for `gcc` ```sh cyberdream /etc/portage/repos.conf # crossdev --stable -t aarch64-unknown-linux-gnu --genv 'USE="cxx multilib fortran -mudflap nls openmp -sanitize"' - * crossdev version: 20171230 * Host Portage ARCH: amd64 * Target Portage ARCH: arm64 * Target System: aarch64-unknown-linux-gnu * Stage: 4 (C/C++ compiler) * ABIs: arm64 * binutils: binutils-[stable] * gcc: gcc-[stable] * headers: linux-headers-[stable] * libc: glibc-[stable] * CROSSDEV_OVERLAY: /usr/local/portage-crossdev * PORT_LOGDIR: /var/log/portage * PORTAGE_CONFIGROOT: / * Portage flags: * leaving metadata/layout.conf alone in /usr/local/portage-crossdev * Log: /var/log/portage/cross-aarch64-unknown-linux-gnu-binutils.log * Emerging cross-binutils ... [ ok ] * Log: /var/log/portage/cross-aarch64-unknown-linux-gnu-linux-headers-quick.log * Emerging cross-linux-headers-quick ... [ ok ] * Log: /var/log/portage/cross-aarch64-unknown-linux-gnu-glibc-headers.log * Emerging cross-glibc-headers ... [ ok ] * Log: /var/log/portage/cross-aarch64-unknown-linux-gnu-gcc-stage1.log * Emerging cross-gcc-stage1 ... [ ok ] * Log: /var/log/portage/cross-aarch64-unknown-linux-gnu-linux-headers.log * Emerging cross-linux-headers ... [ ok ] * Log: /var/log/portage/cross-aarch64-unknown-linux-gnu-glibc.log * Emerging cross-glibc ... [ ok ] * Log: /var/log/portage/cross-aarch64-unknown-linux-gnu-gcc-stage2.log * Emerging cross-gcc-stage2 ... [ ok ] cyberdream /etc/portage/repos.conf # ``` After some time the process will end, and we have the **toolchain** ready to build the code that we want to use. In this case we're going to build the kernel and base system for a [**Rasberry Pi 3**](https://www.raspberrypi.org/). We can check the version of our new tools: ```sh taglio@cyberdream ~ $ aarch64-unknown-linux-gnu-g++ --version aarch64-unknown-linux-gnu-g++ (Gentoo 6.4.0-r1 p1.3) 6.4.0 Copyright (C) 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. taglio@cyberdream ~ $ aarch64-unknown-linux-gnu-c++ --version aarch64-unknown-linux-gnu-c++ (Gentoo 6.4.0-r1 p1.3) 6.4.0 Copyright (C) 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. taglio@cyberdream ~ $aarch64-unknown-linux-gnu-gcc --version aarch64-unknown-linux-gnu-gcc (Gentoo 6.4.0-r1 p1.3) 6.4.0 Copyright (C) 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. taglio@cyberdream ~ $ ``` ## The Raspberry Pi 3 ------ ![a raspberry plant](https://www.urbanseedling.com/wp-content/uploads/2015/03/Raspberry-Festival--600x600.jpg) The **Raspberry Pi** is a [*single board computer*](https://en.wikipedia.org/wiki/Single-board_computer) that have sold more than 19 million of devices. It's developed in the United Kindom by the [**Raspberry Pi Foundation**](https://en.wikipedia.org/wiki/Raspberry_Pi_Foundation) that is a charity with the goal to introduce computer science in third world schools. With its third version it's possible to run a lightweight desktop without any problem under Linux. Look at this screenshot of the [**xfce desktop**](https://xfce.org/) environment. ![raspberry pi3 linux and xfce desktop](https://raw.GitHubusercontent.com/sakaki-/resources/master/raspberrypi/pi3/demo-screenshot-small-3.jpg) Let's begin with the compile process for this single board device. ### The Kernel First we download the latest stable kernel from the official Raspberry Pi [**GitHub kernel repository**](https://GitHub.com/raspberrypi/linux). At the time of writing is the `rpi-4.14.y`. We use this `git` options: - `clone`: Clones a repository into a newly created directory, creates remote-tracking branches for each branch in the cloned repository (visible using git branch -r), and creates and checks out an initial branch that is forked from the cloned repository’s currently active branch. - `--depth`: Create a shallow clone with a history truncated to the specified number of commits (`1`). - `-b`: Clone a determinated branch. ```sh taglio@cyberdream ~/Sources/Rpi3/kbuild $ git clone --depth 1 https://GitHub.com/raspberrypi/linux.git -b rpi-4.14.y Cloning into 'linux'... remote: Counting objects: 65735, done. remote: Compressing objects: 100% (60168/60168), done. Receiving objects: 100% (65735/65735), 174.15 MiB | 7.88 MiB/s, done. remote: Total 65735 (delta 7072), reused 15358 (delta 4598), pack-reused 0 Resolving deltas: 100% (7072/7072), done. Checking out files: 100% (61808/61808), done. taglio@cyberdream ~/Sources/Rpi3/kbuild $ ``` Next compile the kernel, modules, firmware and [u-boot](https://en.wikipedia.org/wiki/Das_U-Boot) stuff. We set two variables: - `ARCH=arm64` - `CROSS_COMPILE=aarch64-unknown-linux-gnu-` And we start `make` using two different options: - `distclean` : Remove all generated files, config, various backup files and editor backup and patch files - `bcmrpi3_defconfig` : Use prestablished config located in `arch/arm64/configs` ([https://ghostbin.com/paste/cg62q](https://ghostbin.com/paste/cg62q)) ```sh taglio@cyberdream ~/Sources/Rpi3/kbuild/linux $ make ARCH=arm64 CROSS_COMPILE=aarch64-unknown-linux-gnu- distclean CLEAN . CLEAN arch/arm64/kernel/vdso CLEAN arch/arm64/kernel CLEAN drivers/firmware/efi/libstub CLEAN drivers/tty/vt CLEAN drivers/video/logo CLEAN kernel/debug/kdb CLEAN kernel CLEAN lib/raid6 CLEAN lib CLEAN usr CLEAN arch/arm64/boot CLEAN arch/arm64/boot/dts/broadcom/../overlays CLEAN arch/arm64/boot/dts/broadcom CLEAN .tmp_versions CLEAN scripts/basic CLEAN scripts/dtc CLEAN scripts/genksyms CLEAN scripts/kconfig CLEAN scripts/mod CLEAN scripts CLEAN include/config include/generated arch/arm64/include/generated CLEAN .config .version Module.symvers taglio@cyberdream ~/Sources/Rpi3/kbuild/linux $ make ARCH=arm64 CROSS_COMPILE=aarch64-unknown-linux-gnu- bcmrpi3_defconfig HOSTCC scripts/basic/fixdep HOSTCC scripts/kconfig/conf.o SHIPPED scripts/kconfig/zconf.tab.c SHIPPED scripts/kconfig/zconf.lex.c HOSTCC scripts/kconfig/zconf.tab.o HOSTLD scripts/kconfig/conf # # configuration written to .config # taglio@cyberdream ~/Sources/Rpi3/kbuild/linux $ ``` Next we start the real kernel cross compile. We use the command `time` to mesure the real minutes to build our `arm64` kernel. With `-j$(nprocs)` we start many threads like many processor core we have. ```sh taglio@cyberdream ~/Sources/Rpi3/kbuild/linux $ time make ARCH=arm64 CROSS_COMPILE=aarch64-unknown-linux-gnu- -j$(nproc) . . . real 5m47.534s user 38m35.320s sys 1m34.610s taglio@cyberdream ~/Sources/Rpi3/kbuild/linux $ ``` You can read about all the output here: [https://ghostbin.com/paste/damwc](https://ghostbin.com/paste/damwc) ### The Firmware Like we've done before lets *shallow clone* [`--depth 1`] the GitHub raspberry firmware repository (after we exec two `ls` to see what we've downloaded): ```sh taglio@cyberdream ~/Sources/Rpi3 $ git clone --depth 1 https://GitHub.com/raspberrypi/firmware Cloning into 'firmware'... remote: Counting objects: 4379, done. remote: Compressing objects: 100% (2676/2676), done. remote: Total 4379 (delta 1498), reused 2183 (delta 1359), pack-reused 0 Receiving objects: 100% (4379/4379), 84.19 MiB | 10.97 MiB/s, done. Resolving deltas: 100% (1498/1498), done. taglio@cyberdream ~/Sources/Rpi3 $ cd firmware/ taglio@cyberdream ~/Sources/Rpi3/firmware $ ls README.md boot documentation extra hardfp modules opt taglio@cyberdream ~/Sources/Rpi3/firmware $ cd boot/ taglio@cyberdream ~/Sources/Rpi3/firmware/boot $ ls -al total 21772 drwxr-xr-x 3 taglio taglio 4096 Apr 17 17:41 . drwxr-xr-x 9 taglio taglio 4096 Apr 17 17:41 .. -rw-r--r-- 1 taglio taglio 18693 Apr 17 17:41 COPYING.linux -rw-r--r-- 1 taglio taglio 1494 Apr 17 17:41 LICENCE.broadcom -rw-r--r-- 1 taglio taglio 22264 Apr 17 17:41 bcm2708-rpi-0-w.dtb -rw-r--r-- 1 taglio taglio 22020 Apr 17 17:41 bcm2708-rpi-b-plus.dtb -rw-r--r-- 1 taglio taglio 21761 Apr 17 17:41 bcm2708-rpi-b.dtb -rw-r--r-- 1 taglio taglio 21474 Apr 17 17:41 bcm2708-rpi-cm.dtb -rw-r--r-- 1 taglio taglio 23044 Apr 17 17:41 bcm2709-rpi-2-b.dtb -rw-r--r-- 1 taglio taglio 24503 Apr 17 17:41 bcm2710-rpi-3-b-plus.dtb -rw-r--r-- 1 taglio taglio 24240 Apr 17 17:41 bcm2710-rpi-3-b.dtb -rw-r--r-- 1 taglio taglio 22952 Apr 17 17:41 bcm2710-rpi-cm3.dtb -rw-r--r-- 1 taglio taglio 52064 Apr 17 17:41 bootcode.bin -rw-r--r-- 1 taglio taglio 6575 Apr 17 17:41 fixup.dat -rw-r--r-- 1 taglio taglio 2599 Apr 17 17:41 fixup_cd.dat -rw-r--r-- 1 taglio taglio 9726 Apr 17 17:41 fixup_db.dat -rw-r--r-- 1 taglio taglio 9730 Apr 17 17:41 fixup_x.dat -rw-r--r-- 1 taglio taglio 4676016 Apr 17 17:41 kernel.img -rw-r--r-- 1 taglio taglio 4922144 Apr 17 17:41 kernel7.img drwxr-xr-x 2 taglio taglio 4096 Apr 17 17:41 overlays -rw-r--r-- 1 taglio taglio 2825124 Apr 17 17:41 start.elf -rw-r--r-- 1 taglio taglio 673444 Apr 17 17:41 start_cd.elf -rw-r--r-- 1 taglio taglio 4968292 Apr 17 17:41 start_db.elf -rw-r--r-- 1 taglio taglio 3912164 Apr 17 17:41 start_x.elf taglio@cyberdream ~/Sources/Rpi3/firmware/boot $ ``` ### The partition table We've to insert the [**microSD card**](https://simple.wikipedia.org/wiki/MicroSD) in our principal Gentoo PC to create the correct partition table for our **Raspberry Pi 3**. The layout have to be: - [partition](https://en.wikipedia.org/wiki/Disk_partitioning) disklabel type (*partitioning scheme*): `DOS` - first primary partition: size `128M`, type `c` (*W95 FAT32 (LBA)*), bootable flag `a` active - second primary partition: size `2G`, type `82` (*Linux swap / Solaris*) - third primary partition: size all, type `83` (*Linux*) Here is the correct commands from the Linux `fdisk` shell: ```sh cyberdream ~ # fdisk /dev/mmcblk0 Welcome to fdisk (util-linux 2.30.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help): o Created a new DOS disklabel with disk identifier 0x718393ba. Command (m for help): p Disk /dev/mmcblk0: 29.8 GiB, 32010928128 bytes, 62521344 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x718393ba Command (m for help): p Disk /dev/mmcblk0: 29.8 GiB, 32010928128 bytes, 62521344 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x718393ba Command (m for help): n Partition type p primary (0 primary, 0 extended, 4 free) e extended (container for logical partitions) Select (default p): p Partition number (1-4, default 1): 1 First sector (2048-62521343, default 2048): Last sector, +sectors or +size{K,M,G,T,P} (2048-62521343, default 62521343): +128M Created a new partition 1 of type 'Linux' and of size 128 MiB. Command (m for help): n Partition type p primary (1 primary, 0 extended, 3 free) e extended (container for logical partitions) Select (default p): p Partition number (2-4, default 2): First sector (264192-62521343, default 264192): Last sector, +sectors or +size{K,M,G,T,P} (264192-62521343, default 62521343): +2G Created a new partition 2 of type 'Linux' and of size 2 GiB. Command (m for help): n Partition type p primary (2 primary, 0 extended, 2 free) e extended (container for logical partitions) Select (default p): p Partition number (3,4, default 3): First sector (4458496-62521343, default 4458496): Last sector, +sectors or +size{K,M,G,T,P} (4458496-62521343, default 62521343): Created a new partition 3 of type 'Linux' and of size 27.7 GiB. Command (m for help): p Disk /dev/mmcblk0: 29.8 GiB, 32010928128 bytes, 62521344 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x718393ba Device Boot Start End Sectors Size Id Type /dev/mmcblk0p1 2048 264191 262144 128M 83 Linux /dev/mmcblk0p2 264192 4458495 4194304 2G 83 Linux /dev/mmcblk0p3 4458496 62521343 58062848 27.7G 83 Linux Command (m for help): a Partition number (1-3, default 3): 1 The bootable flag on partition 1 is enabled now. Command (m for help): t Partition number (1-3, default 3): 1 Hex code (type L to list all codes): c Changed type of partition 'Linux' to 'W95 FAT32 (LBA)'. Command (m for help): t Partition number (1-3, default 3): 2 Hex code (type L to list all codes): 82 Changed type of partition 'Linux' to 'Linux swap / Solaris'. Command (m for help): p Disk /dev/mmcblk0: 29.8 GiB, 32010928128 bytes, 62521344 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x718393ba Device Boot Start End Sectors Size Id Type /dev/mmcblk0p1 * 2048 264191 262144 128M c W95 FAT32 (LBA) /dev/mmcblk0p2 264192 4458495 4194304 2G 82 Linux swap / Solaris /dev/mmcblk0p3 4458496 62521343 58062848 27.7G 83 Linux Command (m for help): w The partition table has been altered. Calling ioctl() to re-read partition table. Syncing disks. cyberdream ~ # ``` Next we format the three partition with the correct `fs` type, using those commands and options: - `mkfs -t vfat -F 32`: used to create an MS-DOS filesystem under Linux. `-F` Specifies the type of file allocation tables used (*in this case 32 bit*). - `mkswap`: sets up a Linux swap area on a device or in a file. - `mkfs -i 8192 -t ext4`: - `-i`: Specify the bytes/inode ratio. `mke2fs` creates an inode for every bytes-per-inode bytes of space on the disk. The larger the bytes-per-inode ratio, the fewer inodes will be created. - `-t`: choose between [`ext{2,3,4}`](https://en.wikipedia.org/wiki/Extended_file_system) ```sh cyberdream ~ # mkfs -t vfat -F 32 /dev/mmcblk0p1 mkfs.fat 4.0 (2016-05-06) cyberdream ~ # mkswap /dev/mmcblk0p2 Setting up swapspace version 1, size = 2 GiB (2147479552 bytes) no label, UUID=0ed9f502-c3a4-4821-b646-91a0cda22dc9 cyberdream ~ # mkfs -i 8192 -t ext4 /dev/mmcblk0p3 mke2fs 1.43.6 (29-Aug-2017) /dev/mmcblk0p3 contains `ISO-8859 text, with very long lines, with no line terminators' data Proceed anyway? (y,N) y Creating filesystem with 7257856 4k blocks and 3630144 inodes Filesystem UUID: fdd18e6c-377b-47e8-9595-46b1f036dd84 Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000 Allocating group tables: done Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done cyberdream ~ # ``` ### The filesystem Next we have to populate the `/boot` (*1*) and `/` (*3*) partitions. Gentoo use the concept of *stage tarballs*; they are archives containing files that will be used in the installation process. More in deep we're going to download `stage3` `arm64` tarballs that contains what the gentoo crew call [a system set](https://wiki.gentoo.org/wiki/System_set_(Portage)); also we're going to verificate that the archive has not been manipulated during the fetch process: ```sh taglio@cyberdream ~/Sources/Rpi3/stage3 $ wget http://distfiles.gentoo.org/experimental/arm64/stage3-arm64-20180305.tar.bz2{,.CONTENTS,.DIGESTS} --2018-04-18 09:16:19-- http://distfiles.gentoo.org/experimental/arm64/stage3-arm64-20180305.tar.bz2 Resolving distfiles.gentoo.org... 137.226.34.46, 216.165.129.135, 64.50.233.100, ... Connecting to distfiles.gentoo.org|137.226.34.46|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 233168546 (222M) [application/octet-stream] Saving to: ‘stage3-arm64-20180305.tar.bz2’ stage3-arm64-201803 100%[===================>] 222.37M 35.4MB/s in 6.6s 2018-04-18 09:16:26 (33.8 MB/s) - ‘stage3-arm64-20180305.tar.bz2’ saved [233168546/233168546] --2018-04-18 09:16:26-- http://distfiles.gentoo.org/experimental/arm64/stage3-arm64-20180305.tar.bz2.CONTENTS Reusing existing connection to distfiles.gentoo.org:80. HTTP request sent, awaiting response... 200 OK Length: 5281799 (5.0M) [application/octet-stream] Saving to: ‘stage3-arm64-20180305.tar.bz2.CONTENTS’ stage3-arm64-201803 100%[===================>] 5.04M 30.3MB/s in 0.2s 2018-04-18 09:16:26 (30.3 MB/s) - ‘stage3-arm64-20180305.tar.bz2.CONTENTS’ saved [5281799/5281799] --2018-04-18 09:16:26-- http://distfiles.gentoo.org/experimental/arm64/stage3-arm64-20180305.tar.bz2.DIGESTS Reusing existing connection to distfiles.gentoo.org:80. HTTP request sent, awaiting response... 200 OK Length: 712 [application/octet-stream] Saving to: ‘stage3-arm64-20180305.tar.bz2.DIGESTS’ stage3-arm64-201803 100%[===================>] 712 --.-KB/s in 0s 2018-04-18 09:16:26 (298 MB/s) - ‘stage3-arm64-20180305.tar.bz2.DIGESTS’ saved [712/712] FINISHED --2018-04-18 09:16:26-- Total wall clock time: 7.3s Downloaded: 3 files, 227M in 6.7s (33.7 MB/s) taglio@cyberdream ~/Sources/Rpi3/stage3 $ ``` Next we verify the `sha512sum` of the tarball using this options: - With `awk` we print in `stdout` only the line containing the `SHA512` hash. - The `sed` invocation is necessary to probably correct an *error* from the Gentoo team (reported [here](https://www.reddit.com/r/Gentoo/comments/8d415b/errata/)) ```sh taglio@cyberdream ~/Sources/Rpi3/stage3 $ awk '/SHA512 HASH/{getline;print}' stage3-arm64-20180305.tar.bz2.DIGESTS | sed s/2008.0/20180305/g | sha512sum --check stage3-arm64-20180305.tar.bz2: OK stage3-arm64-20180305.tar.bz2.CONTENTS: OK taglio@cyberdream ~/Sources/Rpi3/stage3 $ ``` Let's begin to move our files in the *microSD* partitions. After creating the mountpoint `/mnt/piboot` and `/mnt/piroot`, start with the firmware, the kernel and the kernel modules. Speaking about the `/boot` partiotion note that we delete all the `.dtb` file after copying the entire directory in the microSD card. This is why we want to use the `64 bit` version of the **device tree binary** file. A good reference that i found in the web is: [https://events.static.linuxfound.org/sites/events/files/slides/petazzoni-device-tree-dummies.pdf](https://events.static.linuxfound.org/sites/events/files/slides/petazzoni-device-tree-dummies) You can evaluate the output of the command `strings` in a `.dtb` file here: [https://ghostbin.com/paste/gn8wj](https://ghostbin.com/paste/gn8wj) ```sh cyberdream /mnt # mkdir -pv /mnt/pi{boot,root} mkdir: created directory 'piboot' mkdir: created directory 'piroot' cyberdream /mnt # mount -v /dev/mmcblk0p1 /mnt/piboot mount: /dev/mmcblk0p1 mounted on /mnt/piboot. cyberdream /mnt # cyberdream /mnt # mount -v /dev/mmcblk0p3 /mnt/piroot mount: /dev/mmcblk0p3 mounted on /mnt/piroot. cyberdream /mnt # cd /home/taglio/Sources/Rpi3/firmware cyberdream /home/taglio/Sources/Rpi3/firmware # cp -rv boot/* /mnt/piboot/ 'boot/COPYING.linux' -> '/mnt/piboot/COPYING.linux' 'boot/LICENCE.broadcom' -> '/mnt/piboot/LICENCE.broadcom' 'boot/bcm2708-rpi-0-w.dtb' -> '/mnt/piboot/bcm2708-rpi-0-w.dtb' 'boot/bcm2708-rpi-b-plus.dtb' -> '/mnt/piboot/bcm2708-rpi-b-plus.dtb' 'boot/bcm2708-rpi-b.dtb' -> '/mnt/piboot/bcm2708-rpi-b.dtb' 'boot/bcm2708-rpi-cm.dtb' -> '/mnt/piboot/bcm2708-rpi-cm.dtb' 'boot/bcm2709-rpi-2-b.dtb' -> '/mnt/piboot/bcm2709-rpi-2-b.dtb' 'boot/bcm2710-rpi-3-b-plus.dtb' -> '/mnt/piboot/bcm2710-rpi-3-b-plus.dtb' 'boot/bcm2710-rpi-3-b.dtb' -> '/mnt/piboot/bcm2710-rpi-3-b.dtb' 'boot/bcm2710-rpi-cm3.dtb' -> '/mnt/piboot/bcm2710-rpi-cm3.dtb' 'boot/bootcode.bin' -> '/mnt/piboot/bootcode.bin' 'boot/fixup.dat' -> '/mnt/piboot/fixup.dat' 'boot/fixup_cd.dat' -> '/mnt/piboot/fixup_cd.dat' 'boot/fixup_db.dat' -> '/mnt/piboot/fixup_db.dat' 'boot/fixup_x.dat' -> '/mnt/piboot/fixup_x.dat' 'boot/kernel.img' -> '/mnt/piboot/kernel.img' 'boot/kernel7.img' -> '/mnt/piboot/kernel7.img' 'boot/overlays' -> '/mnt/piboot/overlays' 'boot/overlays/README' -> '/mnt/piboot/overlays/README' 'boot/overlays/adau1977-adc.dtbo' -> '/mnt/piboot/overlays/adau1977-adc.dtbo' 'boot/overlays/adau7002-simple.dtbo' -> '/mnt/piboot/overlays/adau7002-simple.dtbo' 'boot/overlays/ads1015.dtbo' -> '/mnt/piboot/overlays/ads1015.dtbo' 'boot/overlays/ads1115.dtbo' -> '/mnt/piboot/overlays/ads1115.dtbo' 'boot/overlays/ads7846.dtbo' -> '/mnt/piboot/overlays/ads7846.dtbo' 'boot/overlays/akkordion-iqdacplus.dtbo' -> '/mnt/piboot/overlays/akkordion-iqdacplus.dtbo' 'boot/overlays/allo-boss-dac-pcm512x-audio.dtbo' -> '/mnt/piboot/overlays/allo-boss-dac-pcm512x-audio.dtbo' 'boot/overlays/allo-digione.dtbo' -> '/mnt/piboot/overlays/allo-digione.dtbo' 'boot/overlays/allo-piano-dac-pcm512x-audio.dtbo' -> '/mnt/piboot/overlays/allo-piano-dac-pcm512x-audio.dtbo' 'boot/overlays/allo-piano-dac-plus-pcm512x-audio.dtbo' -> '/mnt/piboot/overlays/allo-piano-dac-plus-pcm512x-audio.dtbo' 'boot/overlays/applepi-dac.dtbo' -> '/mnt/piboot/overlays/applepi-dac.dtbo' 'boot/overlays/at86rf233.dtbo' -> '/mnt/piboot/overlays/at86rf233.dtbo' 'boot/overlays/audioinjector-addons.dtbo' -> '/mnt/piboot/overlays/audioinjector-addons.dtbo' 'boot/overlays/audioinjector-wm8731-audio.dtbo' -> '/mnt/piboot/overlays/audioinjector-wm8731-audio.dtbo' 'boot/overlays/audremap.dtbo' -> '/mnt/piboot/overlays/audremap.dtbo' 'boot/overlays/bmp085_i2c-sensor.dtbo' -> '/mnt/piboot/overlays/bmp085_i2c-sensor.dtbo' 'boot/overlays/dht11.dtbo' -> '/mnt/piboot/overlays/dht11.dtbo' 'boot/overlays/dionaudio-loco-v2.dtbo' -> '/mnt/piboot/overlays/dionaudio-loco-v2.dtbo' 'boot/overlays/dionaudio-loco.dtbo' -> '/mnt/piboot/overlays/dionaudio-loco.dtbo' 'boot/overlays/dpi18.dtbo' -> '/mnt/piboot/overlays/dpi18.dtbo' 'boot/overlays/dpi24.dtbo' -> '/mnt/piboot/overlays/dpi24.dtbo' 'boot/overlays/dwc-otg.dtbo' -> '/mnt/piboot/overlays/dwc-otg.dtbo' 'boot/overlays/dwc2.dtbo' -> '/mnt/piboot/overlays/dwc2.dtbo' 'boot/overlays/enc28j60-spi2.dtbo' -> '/mnt/piboot/overlays/enc28j60-spi2.dtbo' 'boot/overlays/enc28j60.dtbo' -> '/mnt/piboot/overlays/enc28j60.dtbo' 'boot/overlays/exc3000.dtbo' -> '/mnt/piboot/overlays/exc3000.dtbo' 'boot/overlays/fe-pi-audio.dtbo' -> '/mnt/piboot/overlays/fe-pi-audio.dtbo' 'boot/overlays/goodix.dtbo' -> '/mnt/piboot/overlays/goodix.dtbo' 'boot/overlays/googlevoicehat-soundcard.dtbo' -> '/mnt/piboot/overlays/googlevoicehat-soundcard.dtbo' 'boot/overlays/gpio-ir-tx.dtbo' -> '/mnt/piboot/overlays/gpio-ir-tx.dtbo' 'boot/overlays/gpio-ir.dtbo' -> '/mnt/piboot/overlays/gpio-ir.dtbo' 'boot/overlays/gpio-key.dtbo' -> '/mnt/piboot/overlays/gpio-key.dtbo' 'boot/overlays/gpio-poweroff.dtbo' -> '/mnt/piboot/overlays/gpio-poweroff.dtbo' 'boot/overlays/gpio-shutdown.dtbo' -> '/mnt/piboot/overlays/gpio-shutdown.dtbo' 'boot/overlays/hifiberry-amp.dtbo' -> '/mnt/piboot/overlays/hifiberry-amp.dtbo' 'boot/overlays/hifiberry-dac.dtbo' -> '/mnt/piboot/overlays/hifiberry-dac.dtbo' 'boot/overlays/hifiberry-dacplus.dtbo' -> '/mnt/piboot/overlays/hifiberry-dacplus.dtbo' 'boot/overlays/hifiberry-digi-pro.dtbo' -> '/mnt/piboot/overlays/hifiberry-digi-pro.dtbo' 'boot/overlays/hifiberry-digi.dtbo' -> '/mnt/piboot/overlays/hifiberry-digi.dtbo' 'boot/overlays/hy28a.dtbo' -> '/mnt/piboot/overlays/hy28a.dtbo' 'boot/overlays/hy28b.dtbo' -> '/mnt/piboot/overlays/hy28b.dtbo' 'boot/overlays/i2c-bcm2708.dtbo' -> '/mnt/piboot/overlays/i2c-bcm2708.dtbo' 'boot/overlays/i2c-gpio.dtbo' -> '/mnt/piboot/overlays/i2c-gpio.dtbo' 'boot/overlays/i2c-mux.dtbo' -> '/mnt/piboot/overlays/i2c-mux.dtbo' 'boot/overlays/i2c-pwm-pca9685a.dtbo' -> '/mnt/piboot/overlays/i2c-pwm-pca9685a.dtbo' 'boot/overlays/i2c-rtc-gpio.dtbo' -> '/mnt/piboot/overlays/i2c-rtc-gpio.dtbo' 'boot/overlays/i2c-rtc.dtbo' -> '/mnt/piboot/overlays/i2c-rtc.dtbo' 'boot/overlays/i2c-sensor.dtbo' -> '/mnt/piboot/overlays/i2c-sensor.dtbo' 'boot/overlays/i2c0-bcm2708.dtbo' -> '/mnt/piboot/overlays/i2c0-bcm2708.dtbo' 'boot/overlays/i2c1-bcm2708.dtbo' -> '/mnt/piboot/overlays/i2c1-bcm2708.dtbo' 'boot/overlays/i2s-gpio28-31.dtbo' -> '/mnt/piboot/overlays/i2s-gpio28-31.dtbo' 'boot/overlays/iqaudio-dac.dtbo' -> '/mnt/piboot/overlays/iqaudio-dac.dtbo' 'boot/overlays/iqaudio-dacplus.dtbo' -> '/mnt/piboot/overlays/iqaudio-dacplus.dtbo' 'boot/overlays/iqaudio-digi-wm8804-audio.dtbo' -> '/mnt/piboot/overlays/iqaudio-digi-wm8804-audio.dtbo' 'boot/overlays/jedec-spi-nor.dtbo' -> '/mnt/piboot/overlays/jedec-spi-nor.dtbo' 'boot/overlays/justboom-dac.dtbo' -> '/mnt/piboot/overlays/justboom-dac.dtbo' 'boot/overlays/justboom-digi.dtbo' -> '/mnt/piboot/overlays/justboom-digi.dtbo' 'boot/overlays/lirc-rpi.dtbo' -> '/mnt/piboot/overlays/lirc-rpi.dtbo' 'boot/overlays/mbed-dac.dtbo' -> '/mnt/piboot/overlays/mbed-dac.dtbo' 'boot/overlays/mcp23017.dtbo' -> '/mnt/piboot/overlays/mcp23017.dtbo' 'boot/overlays/mcp23s17.dtbo' -> '/mnt/piboot/overlays/mcp23s17.dtbo' 'boot/overlays/mcp2515-can0.dtbo' -> '/mnt/piboot/overlays/mcp2515-can0.dtbo' 'boot/overlays/mcp2515-can1.dtbo' -> '/mnt/piboot/overlays/mcp2515-can1.dtbo' 'boot/overlays/mcp3008.dtbo' -> '/mnt/piboot/overlays/mcp3008.dtbo' 'boot/overlays/mcp3202.dtbo' -> '/mnt/piboot/overlays/mcp3202.dtbo' 'boot/overlays/media-center.dtbo' -> '/mnt/piboot/overlays/media-center.dtbo' 'boot/overlays/midi-uart0.dtbo' -> '/mnt/piboot/overlays/midi-uart0.dtbo' 'boot/overlays/midi-uart1.dtbo' -> '/mnt/piboot/overlays/midi-uart1.dtbo' 'boot/overlays/mmc.dtbo' -> '/mnt/piboot/overlays/mmc.dtbo' 'boot/overlays/mpu6050.dtbo' -> '/mnt/piboot/overlays/mpu6050.dtbo' 'boot/overlays/mz61581.dtbo' -> '/mnt/piboot/overlays/mz61581.dtbo' 'boot/overlays/papirus.dtbo' -> '/mnt/piboot/overlays/papirus.dtbo' 'boot/overlays/pi3-act-led.dtbo' -> '/mnt/piboot/overlays/pi3-act-led.dtbo' 'boot/overlays/pi3-disable-bt.dtbo' -> '/mnt/piboot/overlays/pi3-disable-bt.dtbo' 'boot/overlays/pi3-disable-wifi.dtbo' -> '/mnt/piboot/overlays/pi3-disable-wifi.dtbo' 'boot/overlays/pi3-miniuart-bt.dtbo' -> '/mnt/piboot/overlays/pi3-miniuart-bt.dtbo' 'boot/overlays/pibell.dtbo' -> '/mnt/piboot/overlays/pibell.dtbo' 'boot/overlays/piscreen.dtbo' -> '/mnt/piboot/overlays/piscreen.dtbo' 'boot/overlays/piscreen2r.dtbo' -> '/mnt/piboot/overlays/piscreen2r.dtbo' 'boot/overlays/pisound.dtbo' -> '/mnt/piboot/overlays/pisound.dtbo' 'boot/overlays/pitft22.dtbo' -> '/mnt/piboot/overlays/pitft22.dtbo' 'boot/overlays/pitft28-capacitive.dtbo' -> '/mnt/piboot/overlays/pitft28-capacitive.dtbo' 'boot/overlays/pitft28-resistive.dtbo' -> '/mnt/piboot/overlays/pitft28-resistive.dtbo' 'boot/overlays/pitft35-resistive.dtbo' -> '/mnt/piboot/overlays/pitft35-resistive.dtbo' 'boot/overlays/pps-gpio.dtbo' -> '/mnt/piboot/overlays/pps-gpio.dtbo' 'boot/overlays/pwm-2chan.dtbo' -> '/mnt/piboot/overlays/pwm-2chan.dtbo' 'boot/overlays/pwm-ir-tx.dtbo' -> '/mnt/piboot/overlays/pwm-ir-tx.dtbo' 'boot/overlays/pwm.dtbo' -> '/mnt/piboot/overlays/pwm.dtbo' 'boot/overlays/qca7000.dtbo' -> '/mnt/piboot/overlays/qca7000.dtbo' 'boot/overlays/rotary-encoder.dtbo' -> '/mnt/piboot/overlays/rotary-encoder.dtbo' 'boot/overlays/rpi-backlight.dtbo' -> '/mnt/piboot/overlays/rpi-backlight.dtbo' 'boot/overlays/rpi-cirrus-wm5102.dtbo' -> '/mnt/piboot/overlays/rpi-cirrus-wm5102.dtbo' 'boot/overlays/rpi-dac.dtbo' -> '/mnt/piboot/overlays/rpi-dac.dtbo' 'boot/overlays/rpi-display.dtbo' -> '/mnt/piboot/overlays/rpi-display.dtbo' 'boot/overlays/rpi-ft5406.dtbo' -> '/mnt/piboot/overlays/rpi-ft5406.dtbo' 'boot/overlays/rpi-proto.dtbo' -> '/mnt/piboot/overlays/rpi-proto.dtbo' 'boot/overlays/rpi-sense.dtbo' -> '/mnt/piboot/overlays/rpi-sense.dtbo' 'boot/overlays/rpi-tv.dtbo' -> '/mnt/piboot/overlays/rpi-tv.dtbo' 'boot/overlays/rra-digidac1-wm8741-audio.dtbo' -> '/mnt/piboot/overlays/rra-digidac1-wm8741-audio.dtbo' 'boot/overlays/sc16is750-i2c.dtbo' -> '/mnt/piboot/overlays/sc16is750-i2c.dtbo' 'boot/overlays/sc16is752-i2c.dtbo' -> '/mnt/piboot/overlays/sc16is752-i2c.dtbo' 'boot/overlays/sc16is752-spi1.dtbo' -> '/mnt/piboot/overlays/sc16is752-spi1.dtbo' 'boot/overlays/sdhost.dtbo' -> '/mnt/piboot/overlays/sdhost.dtbo' 'boot/overlays/sdio-1bit.dtbo' -> '/mnt/piboot/overlays/sdio-1bit.dtbo' 'boot/overlays/sdio.dtbo' -> '/mnt/piboot/overlays/sdio.dtbo' 'boot/overlays/sdtweak.dtbo' -> '/mnt/piboot/overlays/sdtweak.dtbo' 'boot/overlays/smi-dev.dtbo' -> '/mnt/piboot/overlays/smi-dev.dtbo' 'boot/overlays/smi-nand.dtbo' -> '/mnt/piboot/overlays/smi-nand.dtbo' 'boot/overlays/smi.dtbo' -> '/mnt/piboot/overlays/smi.dtbo' 'boot/overlays/spi-gpio35-39.dtbo' -> '/mnt/piboot/overlays/spi-gpio35-39.dtbo' 'boot/overlays/spi-rtc.dtbo' -> '/mnt/piboot/overlays/spi-rtc.dtbo' 'boot/overlays/spi0-cs.dtbo' -> '/mnt/piboot/overlays/spi0-cs.dtbo' 'boot/overlays/spi0-hw-cs.dtbo' -> '/mnt/piboot/overlays/spi0-hw-cs.dtbo' 'boot/overlays/spi1-1cs.dtbo' -> '/mnt/piboot/overlays/spi1-1cs.dtbo' 'boot/overlays/spi1-2cs.dtbo' -> '/mnt/piboot/overlays/spi1-2cs.dtbo' 'boot/overlays/spi1-3cs.dtbo' -> '/mnt/piboot/overlays/spi1-3cs.dtbo' 'boot/overlays/spi2-1cs.dtbo' -> '/mnt/piboot/overlays/spi2-1cs.dtbo' 'boot/overlays/spi2-2cs.dtbo' -> '/mnt/piboot/overlays/spi2-2cs.dtbo' 'boot/overlays/spi2-3cs.dtbo' -> '/mnt/piboot/overlays/spi2-3cs.dtbo' 'boot/overlays/superaudioboard.dtbo' -> '/mnt/piboot/overlays/superaudioboard.dtbo' 'boot/overlays/sx150x.dtbo' -> '/mnt/piboot/overlays/sx150x.dtbo' 'boot/overlays/tinylcd35.dtbo' -> '/mnt/piboot/overlays/tinylcd35.dtbo' 'boot/overlays/uart0.dtbo' -> '/mnt/piboot/overlays/uart0.dtbo' 'boot/overlays/uart1.dtbo' -> '/mnt/piboot/overlays/uart1.dtbo' 'boot/overlays/upstream-aux-interrupt.dtbo' -> '/mnt/piboot/overlays/upstream-aux-interrupt.dtbo' 'boot/overlays/upstream.dtbo' -> '/mnt/piboot/overlays/upstream.dtbo' 'boot/overlays/vc4-fkms-v3d.dtbo' -> '/mnt/piboot/overlays/vc4-fkms-v3d.dtbo' 'boot/overlays/vc4-kms-v3d.dtbo' -> '/mnt/piboot/overlays/vc4-kms-v3d.dtbo' 'boot/overlays/vga666.dtbo' -> '/mnt/piboot/overlays/vga666.dtbo' 'boot/overlays/w1-gpio-pullup.dtbo' -> '/mnt/piboot/overlays/w1-gpio-pullup.dtbo' 'boot/overlays/w1-gpio.dtbo' -> '/mnt/piboot/overlays/w1-gpio.dtbo' 'boot/overlays/wittypi.dtbo' -> '/mnt/piboot/overlays/wittypi.dtbo' 'boot/start.elf' -> '/mnt/piboot/start.elf' 'boot/start_cd.elf' -> '/mnt/piboot/start_cd.elf' 'boot/start_db.elf' -> '/mnt/piboot/start_db.elf' 'boot/start_x.elf' -> '/mnt/piboot/start_x.elf' cyberdream /home/taglio/Sources/Rpi3/firmware # cd ../kbuild/linux/ cyberdream /home/taglio/Sources/Rpi3/kbuild/linux # rm /mnt/piboot/*.dtb cyberdream /home/taglio/Sources/Rpi3/kbuild/linux # cp -v arch/arm64/boot/dts/broadcom/bcm2710-rpi-3-b-plus.dtb /mnt/piboot/ 'arch/arm64/boot/dts/broadcom/bcm2710-rpi-3-b-plus.dtb' -> '/mnt/piboot/bcm2710-rpi-3-b-plus.dtb' cyberdream /home/taglio/Sources/Rpi3/kbuild/linux # cp -v arch/arm64/boot/dts/broadcom/bcm{2710,2837}-rpi-3-b.dtb /mnt/piboot/ 'arch/arm64/boot/dts/broadcom/bcm2710-rpi-3-b.dtb' -> '/mnt/piboot/bcm2710-rpi-3-b.dtb' 'arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dtb' -> '/mnt/piboot/bcm2837-rpi-3-b.dtb' cyberdream /home/taglio/Sources/Rpi3/kbuild/linux # ``` Going ahead with the kernel and its related modules; we can see that we invoque `modules_install` option of `make` declaring three variables: 1. `ARCH=arm64` 2. `CROSS_COMPILE=aarch64-unknown-linux-gnu-` 3. `INSTALL_MOD_PATH="/mnt/piroot"` You can appreciate the output of the entire command here: [https://ghostbin.com/paste/okxwe](https://ghostbin.com/paste/okxwe) ```sh cyberdream /home/taglio/Sources/Rpi3/kbuild/linux # cp -v arch/arm64/boot/Image /mnt/piboot/kernel8.img 'arch/arm64/boot/Image' -> '/mnt/piboot/kernel8.img' cyberdream /home/taglio/Sources/Rpi3/kbuild/linux # make ARCH=arm64 CROSS_COMPILE=aarch64-unknown-linux-gnu- modules_install INSTALL_MOD_PATH="/mnt/piroot" . . . DEPMOD 4.14.34-v8+ cyberdream /home/taglio/Sources/Rpi3/kbuild/linux # ``` The result of an `ls` of the `/boot` carpet is: ```sh cyberdream /mnt/piboot # ls -al total 34634 drwxr-xr-x 3 root root 2048 Apr 18 15:13 . drwxr-xr-x 7 root root 4096 Apr 18 09:59 .. -rwxr-xr-x 1 root root 18693 Apr 18 13:47 COPYING.linux -rwxr-xr-x 1 root root 1494 Apr 18 13:47 LICENCE.broadcom -rwxr-xr-x 1 root root 24519 Apr 18 15:13 bcm2710-rpi-3-b-plus.dtb -rwxr-xr-x 1 root root 24256 Apr 18 15:13 bcm2710-rpi-3-b.dtb -rwxr-xr-x 1 root root 17314 Apr 18 15:13 bcm2837-rpi-3-b.dtb -rwxr-xr-x 1 root root 52064 Apr 18 13:47 bootcode.bin -rwxr-xr-x 1 root root 6575 Apr 18 13:47 fixup.dat -rwxr-xr-x 1 root root 2599 Apr 18 13:47 fixup_cd.dat -rwxr-xr-x 1 root root 9726 Apr 18 13:47 fixup_db.dat -rwxr-xr-x 1 root root 9730 Apr 18 13:47 fixup_x.dat -rwxr-xr-x 1 root root 4676016 Apr 18 13:47 kernel.img -rwxr-xr-x 1 root root 4922144 Apr 18 13:47 kernel7.img -rwxr-xr-x 1 root root 13300224 Apr 18 17:46 kernel8.img drwxr-xr-x 2 root root 11264 Apr 18 13:47 overlays -rwxr-xr-x 1 root root 2825124 Apr 18 13:47 start.elf -rwxr-xr-x 1 root root 673444 Apr 18 13:47 start_cd.elf -rwxr-xr-x 1 root root 4968292 Apr 18 13:47 start_db.elf -rwxr-xr-x 1 root root 3912164 Apr 18 13:47 start_x.elf cyberdream /mnt/piboot # ``` Next we're going to extract the `stage3` tarball in the `/` mounted over `/mnt/piroot`. We're going to use `tar` in an advaced mode: - `-x`: Extract files from an archive. - `-v`: Verbosely list files processed. - `-j`: Filter the archive through bzip2. - `-p`: Extract information about file permissions. - `-f`: Use archive file or device ARCHIVE (`stage3-arm64-20180305.tar.bz2`) - `--xattrs-include`: Specify the include PATTERN for xattr keys. (`*.*`) - `--numeric-owner`: Always use numbers for user/group names. Full output here: [https://ghostbin.com/paste/yvs2x](https://ghostbin.com/paste/yvs2x) ```sh cyberdream /mnt/piroot # tar xvjpf /home/taglio/Sources/Rpi3/stage3/stage3-arm64-20180305.tar.bz2 --xattrs-include='*.*' --numeric-owner . . . cyberdream /mnt/piroot # ``` ### The portage latest snapshot The next step is to install a **Portage** snapshot, a set of files updated on a daily basis informing Portage what software is available to install, what profiles are available, and so on. ```sh taglio@cyberdream ~/Sources/Rpi3/portage $ wget http://distfiles.gentoo.org/snapshots/portage-latest.tar.bz2{,.gpgsig,.md5sum} --2018-04-20 10:15:21-- http://distfiles.gentoo.org/snapshots/portage-latest.tar.bz2 Resolving distfiles.gentoo.org... 64.50.236.52, 140.211.166.134, 137.226.34.46, ... Connecting to distfiles.gentoo.org|64.50.236.52|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 52621953 (50M) [application/x-bzip2] Saving to: ‘portage-latest.tar.bz2’ portage-latest.tar. 100%[===================>] 50.18M 6.93MB/s in 9.5s 2018-04-20 10:15:31 (5.30 MB/s) - ‘portage-latest.tar.bz2’ saved [52621953/52621953] --2018-04-20 10:15:31-- http://distfiles.gentoo.org/snapshots/portage-latest.tar.bz2.gpgsig Reusing existing connection to distfiles.gentoo.org:80. HTTP request sent, awaiting response... 200 OK Length: 963 [application/x-bzip2] Saving to: ‘portage-latest.tar.bz2.gpgsig’ portage-latest.tar. 100%[===================>] 963 --.-KB/s in 0s 2018-04-20 10:15:31 (297 MB/s) - ‘portage-latest.tar.bz2.gpgsig’ saved [963/963] --2018-04-20 10:15:31-- http://distfiles.gentoo.org/snapshots/portage-latest.tar.bz2.md5sum Reusing existing connection to distfiles.gentoo.org:80. HTTP request sent, awaiting response... 200 OK Length: 57 [application/x-bzip2] Saving to: ‘portage-latest.tar.bz2.md5sum’ portage-latest.tar. 100%[===================>] 57 --.-KB/s in 0s 2018-04-20 10:15:31 (21.2 MB/s) - ‘portage-latest.tar.bz2.md5sum’ saved [57/57] FINISHED --2018-04-20 10:15:31-- Total wall clock time: 10s Downloaded: 3 files, 50M in 9.5s (5.30 MB/s) taglio@cyberdream ~/Sources/Rpi3/portage $ ``` Next to verify the gpg signature we're going to fetch with `gpg` the latest key from the *Gentoo Portage Snapshot signing Key (Automated signing key)*. We have to find the `Key ID` in the official page de Release Engeneer: [https://wiki.gentoo.org/wiki/Project:RelEng#Keys](https://wiki.gentoo.org/wiki/Project:RelEng#Keys) In our case is `0xDB6B8C1F96D8BF6D`. Various options to launch with `gpg`: - `--search`: search for keys on a keyserver. - `1`: public key imported. - `--edit-key`: Present a menu which enables you to do most of the key management related tasks. - `fpr`: show key fingerprint. - `trust`: change the ownertrust. - `5`: ultimate trust. - `--verify`: Assume that the first argument is a signed file and verify it without generating any output. With no arguments, the signature packet is read from STDIN. If only one argument is given, the specified file is expected to include a complete signature. ```sh taglio@cyberdream ~/Sources/Rpi3/portage $ gpg --search 0xDB6B8C1F96D8BF6D gpg: data source: http://37.191.226.104:11371 (1) Gentoo Portage Snapshot Signing Key (Automated Signing Key) 4096 bit RSA key 0xDB6B8C1F96D8BF6D, created: 2011-11-25, expires: 2019-01-01 Keys 1-1 of 1 for "0xDB6B8C1F96D8BF6D". Enter number(s), N)ext, or Q)uit > 1 gpg: key 0xDB6B8C1F96D8BF6D: 13 signatures not checked due to missing keys gpg: key 0xDB6B8C1F96D8BF6D: public key "Gentoo Portage Snapshot Signing Key (Automated Signing Key)" imported gpg: marginals needed: 3 completes needed: 1 trust model: pgp gpg: depth: 0 valid: 3 signed: 0 trust: 0-, 0q, 0n, 0m, 0f, 3u gpg: next trustdb check due at 2019-08-22 gpg: Total number processed: 1 gpg: imported: 1 taglio@cyberdream ~/Sources/Rpi3/portage taglio@cyberdream ~/Sources/Rpi3/portage $ gpg --edit-key 0xDB6B8C1F96D8BF6D gpg (GnuPG) 2.2.6; Copyright (C) 2018 Free Software Foundation, Inc. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. pub rsa4096/0xDB6B8C1F96D8BF6D created: 2011-11-25 expires: 2019-01-01 usage: C trust: unknown validity: unknown sub rsa4096/0xEC590EEAC9189250 created: 2011-11-25 expires: 2019-01-01 usage: S [ unknown] (1). Gentoo Portage Snapshot Signing Key (Automated Signing Key) gpg> fpr pub rsa4096/0xDB6B8C1F96D8BF6D 2011-11-25 Gentoo Portage Snapshot Signing Key (Automated Signing Key) Primary key fingerprint: DCD0 5B71 EAB9 4199 527F 44AC DB6B 8C1F 96D8 BF6D gpg> trust pub rsa4096/0xDB6B8C1F96D8BF6D created: 2011-11-25 expires: 2019-01-01 usage: C trust: unknown validity: unknown sub rsa4096/0xEC590EEAC9189250 created: 2011-11-25 expires: 2019-01-01 usage: S [ unknown] (1). Gentoo Portage Snapshot Signing Key (Automated Signing Key) Please decide how far you trust this user to correctly verify other users' keys (by looking at passports, checking fingerprints from different sources, etc.) 1 = I don't know or won't say 2 = I do NOT trust 3 = I trust marginally 4 = I trust fully 5 = I trust ultimately m = back to the main menu Your decision? 5 Do you really want to set this key to ultimate trust? (y/N) y pub rsa4096/0xDB6B8C1F96D8BF6D created: 2011-11-25 expires: 2019-01-01 usage: C trust: ultimate validity: unknown sub rsa4096/0xEC590EEAC9189250 created: 2011-11-25 expires: 2019-01-01 usage: S [unknown] (1). Gentoo Portage Snapshot Signing Key (Automated Signing Key) Please note that the shown key validity is not necessarily correct unless you restart the program. taglio@cyberdream ~/Sources/Rpi3/portage $ mv portage-latest.tar.bz2.gpgsig portage-latest.tar.bz2.sig taglio@cyberdream ~/Sources/Rpi3/portage $ gpg --verify portage-latest.tar.bz2.sig gpg: assuming signed data in 'portage-latest.tar.bz2' gpg: Signature made Fri 20 Apr 2018 02:51:21 CEST gpg: using RSA key E1D6ABB63BFCFB4BA02FDF1CEC590EEAC9189250 gpg: Good signature from "Gentoo Portage Snapshot Signing Key (Automated Signing Key)" [ultimate] Primary key fingerprint: DCD0 5B71 EAB9 4199 527F 44AC DB6B 8C1F 96D8 BF6D Subkey fingerprint: E1D6 ABB6 3BFC FB4B A02F DF1C EC59 0EEA C918 9250 taglio@cyberdream ~/Sources/Rpi3/portage $ ``` `untar` the tarball following the last `tar` command: ```sh cyberdream /mnt/piroot/usr # tar xvjpf /home/taglio/Sources/Rpi3/portage/portage-latest.tar.bz2 --xattrs-include='*.*' --numeric-owner . . . cyberdream /mnt/piroot/usr # ``` ### Wireless and bluetooth closed source firmware The chipset of the wi-fi interface that come inside the single-board Raspberry Pi 3 is a **Broadcom BRM43430** and needs two files to be present under `/lib/firmware/brcm`. The `.bin` is a [*binary blob*](https://en.wikipedia.org/wiki/Binary_blob) closed source piece of software. We can download it from the GitHub.com repository of the [**armbian**](https://www.armbian.com/) linux distribution. `brcmfmac` is a *Full-mac* driver we can read more about it here: [https://wireless.wiki.kernel.org/en/developers/documentation/glossary](https://wireless.wiki.kernel.org/en/developers/documentation/glossary) ```sh taglio@cyberdream ~/Sources/Rpi3/wireless_firmware $ wget https://raw.GitHubusercontent.com/armbian/firmware/master/brcm/brcmfmac43430-sdio.txt --2018-04-25 02:18:14-- https://raw.GitHubusercontent.com/armbian/firmware/master/brcm/brcmfmac43430-sdio.txt Resolving raw.GitHubusercontent.com... 151.101.36.133 Connecting to raw.GitHubusercontent.com|151.101.36.133|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 902 [text/plain] Saving to: ‘brcmfmac43430-sdio.txt’ brcmfmac43430-sdio. 100%[===================>] 902 --.-KB/s in 0s 2018-04-25 02:18:15 (309 MB/s) - ‘brcmfmac43430-sdio.txt’ saved [902/902] taglio@cyberdream ~/Sources/Rpi3/wireless_firmware $ wget https://GitHub.com/armbian/firmware/raw/master/brcm/brcmfmac43430-sdio.bin --2018-04-25 02:21:43-- https://GitHub.com/armbian/firmware/raw/master/brcm/brcmfmac43430-sdio.bin Resolving GitHub.com... 192.30.253.112, 192.30.253.113 Connecting to GitHub.com|192.30.253.112|:443... connected. HTTP request sent, awaiting response... 302 Found Location: https://raw.GitHubusercontent.com/armbian/firmware/master/brcm/brcmfmac43430-sdio.bin [following] --2018-04-25 02:21:44-- https://raw.GitHubusercontent.com/armbian/firmware/master/brcm/brcmfmac43430-sdio.bin Resolving raw.GitHubusercontent.com... 151.101.36.133 Connecting to raw.GitHubusercontent.com|151.101.36.133|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 416477 (407K) [application/octet-stream] Saving to: ‘brcmfmac43430-sdio.bin’ brcmfmac43430-sdio. 100%[===================>] 406.72K 1.61MB/s in 0.2s 2018-04-25 02:21:44 (1.61 MB/s) - ‘brcmfmac43430-sdio.bin’ saved [416477/416477] taglio@cyberdream ~/Sources/Rpi3/wireless_firmware $ cyberdream /mnt/piroot/lib # mkdir -pv firmware/brcm mkdir: created directory 'firmware' mkdir: created directory 'firmware/brcm' cyberdream /mnt/piroot/lib # cp -v /home/taglio/Sources/Rpi3/wireless_firmware/brcmfmac43430-sdio.* firmware/brcm/ '/home/taglio/Sources/Rpi3/wireless_firmware/brcmfmac43430-sdio.bin' -> 'firmware/brcm/brcmfmac43430-sdio.bin' '/home/taglio/Sources/Rpi3/wireless_firmware/brcmfmac43430-sdio.txt' -> 'firmware/brcm/brcmfmac43430-sdio.txt' cyberdream /mnt/piroot/lib # ``` Next we have to fetch another *bynary blob* for the bluetooth chip that is a **BCM2837** and it is connected to the [**hardware UART**](https://en.wikipedia.org/wiki/Universal_asynchronous_receiver-transmitter). We can do it from the Raspbian [bluez-firmware](https://GitHub.com/RPi-Distro/bluez-firmware/tree/master/broadcom) GitHub repository. ```sh taglio@cyberdream ~/Sources/Rpi3/wireless_firmware $ wget https://raw.githubusercontent.com/RPi-Distro/bluez-firmware/master/broadcom/BCM43430A1.hcd --2018-04-25 02:51:22-- https://raw.githubusercontent.com/RPi-Distro/bluez-firmware/master/broadcom/BCM43430A1.hcd Resolving raw.githubusercontent.com... 151.101.36.133 Connecting to raw.githubusercontent.com|151.101.36.133|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 36264 (35K) [application/octet-stream] Saving to: ‘BCM43430A1.hcd’ BCM43430A1.hcd 100%[===================>] 35.41K --.-KB/s in 0.06s 2018-04-25 02:51:22 (629 KB/s) - ‘BCM43430A1.hcd’ saved [36264/36264] taglio@cyberdream ~/Sources/Rpi3/wireless_firmware $ cyberdream /mnt/piroot/lib # cp -v /home/taglio/Sources/Rpi3/wireless_firmware/BCM43430A1.hcd firmware/brcm/ '/home/taglio/Sources/Rpi3/wireless_firmware/BCM43430A1.hcd' -> 'firmware/brcm/BCM43430A1.hcd' cyberdream /mnt/piroot/lib # ``` ### Custom config files We've to change some files under `/mnt/piroot` and `/mnt/piboot` to make the *first run* possible. They are: - `etc/fstab`: static information about the filesystems. - `config.txt`: more information at [https://elinux.org/RPiconfig](https://elinux.org/RPiconfig) - `cmdline.txt`: more information at [https://elinux.org/RPi_cmdline.txt](https://elinux.org/RPi_cmdline.txt) - `etc/conf.d/keymaps`: keyboard table descriptions for loadkeys and dumpkeys. - `etc/shadow`: shadowed password file (set `root` passwod to *raspberry*). ```sh cyberdream /mnt/piroot/etc # cat > fstab << EOF > /dev/mmcblk0p1 /boot vfat noauto,noatime 1 2 > /dev/mmcblk0p2 none swap sw 0 0 > /dev/mmcblk0p3 / ext4 noatime 0 1 > EOF cyberdream /mnt/piroot/etc # ``` ```sh cyberdream /mnt/piboot # cat > config.txt << EOF > # have a properly sized image > disable_overscan=1 > > # lets have the VC4 hardware accelerated video > dtoverlay=vc4-fkms-v3d > > # for sound over HDMI > hdmi_drive=2 > > # Enable audio (loads snd_bcm2835) > dtparam=audioon > > # gpu_mem is for closed-source driver only; since we are only using the > # open-source driver here, set low > gpu_mem=16 > EOF cyberdream /mnt/piboot # ``` ```sh cyberdream /mnt/piboot # cat > cmdline.txt << EOF > root=/dev/mmcblk0p3 rootfstype=ext4 rootwait > EOF cyberdream /mnt/piboot # ``` ```sh cyberdream /mnt/piroot/etc/conf.d # cat > keymaps << EOF > # Use keymap to specify the default console keymap. There is a complete tree > # of keymaps in /usr/share/keymaps to choose from. > keymap='es' > > # Should we first load the 'windowkeys' console keymap? Most x86 users will > # say "yes" here. Note that non-x86 users should leave it as "no". > # Loading this keymap will enable VT switching (like ALT+Left/Right) > # using the special windows keys on the linux console. > windowkeys="YES" > > # The maps to load for extended keyboards. Most users will leave this as is. > extended_keymaps="" > #extended_keymaps="backspace keypad euro2" > > # Tell dumpkeys(1) to interpret character action codes to be > # from the specified character set. > # This only matters if you set unicode="yes" in /etc/rc.conf. > # For a list of valid sets, run `dumpkeys --help` > dumpkeys_charset="" > > # Some fonts map AltGr-E to the currency symbol instead of the Euro. > # To fix this, set to "yes" > fix_euro="NO" > EOF cyberdream /mnt/piroot/etc/conf.d # ``` ```sh cyberdream /mnt/piroot/etc # cat > shadow << EOF > root:/Td5iP$/7Asdgq0ux2sgNkklnndcG4g3493kUYfrrdenBXjxBxEsoLneJpDAwOyX/kkpFB4pU5dlhHEyN0SK4eh/WpmO0:10770:0::::: > halt:*:9797:0::::: > operator:*:9797:0::::: > shutdown:*:9797:0::::: > sync:*:9797:0::::: > bin:*:9797:0::::: > daemon:*:9797:0::::: > adm:*:9797:0::::: > lp:*:9797:0::::: > news:*:9797:0::::: > uucp:*:9797:0::::: > portage:*:9797:0::::: > nobody:*:9797:0::::: > man:!:17595:::::: > sshd:!:17595:::::: > EOF cyberdream /mnt/piroot/etc # ``` ### First boot `umount` and `sync` the *microSD* partition and insert it in the **Raspberry pi 3** slot. ```sh cyberdream ~ # umount -v /mnt/piroot/ umount: /mnt/piroot/ unmounted cyberdream ~ # umount -v /mnt/piboot/ umount: /mnt/piboot/ unmounted cyberdream ~ # sync cyberdream ~ # ``` Connect an *HDMI* cable to a monitor and a *USB* mouse and keyboard to the **Raspberry pi 3** ports.