There are two tarballs here Pi3_64_boot_20170329.tbz2 and Pi3_64_root_20170329.tbz2 contents.txt is a lish of packages, versions and useflags installed on the root partition. Pi3_64_boot_20170329.tbz2 untar to the first partition on the SD card. It must be fat32. Pi3_64_root_20170329.tbz2 untar to what will be sda1 on the Pi3 It must be ext4. An 8G USB stick will get you started. Boot it like this before you change anything. Root is about 6G, so it will all fit onto an 8G microSD card, just. Well, change the console keymap unless you like dvorak-uk The root password is raspberry, ssh allows root password logins. User roy has password raspberrypi but as you don't get /home, /home/roy is missing. Log in as root, delete user roy and make your own normal user. What you get. A bootable 64 bit image for the Pi3. Root and /boot anyway. All the build tweaks are in /etc/portage/ so emerge -e @world might work. Expect it to take about a week 24/7 though Its almost all built with gcc-6.x and the gold linker too, which is the default on this install. gcc-5.4.0 is still there, just in case. What works:- * USB - console over serial port is not supported * Ethernet - requires USB * microSD - seems to have DMA now too * WiFi - it helps if you get the right *.txt file * bluetooth - its a low value of 'works'. keyboards work * vc4 hardware - video acceleration (uses the Open Source driver). * hdmi sound bluetooth uses the UART that was used for the serial console. You can put the serial console on the mini-UART if you really want to, or do without bluetooth. Whats still to come * analogue sound and video should work but is untested. bluealsa is installed for sound over bluetooth, it needs some 'fine tuning' or possibly pulseaudio. bluez is lightly patched. See /etc/portage/patches Read and understand /etc/fstab Swap needs to be at least 2G to build some things. My complete filesystem looks like:- Pi3 64bit ~ # df -hT Filesystem Type Size Used Avail Use% Mounted on /dev/root ext4 74G 3.6G 66G 6% / devtmpfs devtmpfs 10M 0 10M 0% /dev tmpfs tmpfs 92M 304K 92M 1% /run shm tmpfs 459M 0 459M 0% /dev/shm cgroup_root tmpfs 10M 0 10M 0% /sys/fs/cgroup /dev/sda3 ext4 17G 2.7G 13G 18% /var/tmp/portage /dev/sda4 ext4 5.4G 851M 4.3G 17% /usr/portage /dev/sda5 ext4 37G 11G 25G 30% /var/cache/distfiles /dev/sda6 ext4 50G 33G 15G 70% /home /dev/sda7 ext4 46G 4.3G 40G 10% /packages /dev/sda8 ext4 56G 9.1G 44G 18% /usr/src /dev/sda9 ext4 19G 203M 18G 2% /opt /dev/mmcblk0p1 vfat 7.4G 122M 7.3G 2% /boot Only /dev/sda1 and /dev/mmcblk0p1 are provided here. The kernel is git raspberrypi-sources 4.10.y which has been snuck in with some 64 bit support with absolutely no fanfare at all. Its not supported by the Raspberry Pi Foundation. https://github.com/raspberrypi/linux Its almost the default config. The default CPU govener changed to "on demand", so the Pi switches between 600MHz and 1.2GHz operation. U-Boot is not needed. The kernel is called kernel8.img and the dtb is bcm2710-rpi-3-b.dtb rather that the expected bcm2735-rpi-3-b.dtb. The kernel makes bcm2710-rpi-3-b.dtb either 32 bit or 64 bit, depending on the ARCH= passed at build time. To put root on the SD card, fix cmdline.txt and /etc/fstab. Before you do that, consider the following speed sequential read speed tests. Pi3 64bit ~ # hdparm -tT /dev/sda /dev/sda: Timing cached reads: 1150 MB in 2.00 seconds = 575.06 MB/sec Timing buffered disk reads: 100 MB in 3.05 seconds = 32.83 MB/sec /dev/mmcblk0: Timing cached reads: 1270 MB in 2.00 seconds = 634.50 MB/sec Timing buffered disk reads: 64 MB in 3.02 seconds = 21.21 MB/sec sda is a USB HDD. mmcblk0 is a random XC-1 card. microSD write speeds will vary wildly from card to card. Given # genlop -t libreoffice Wed Nov 23 22:51:14 2016 >>> app-office/libreoffice-5.2.3.3 merge time: 19 hours, 36 minutes and 35 seconds. This is a copy of my working environment which I'm using to add ~arm64 keywords to things. Not everything works. Xfce works, try startxfce4 as your normal user. Its only turbo-framebuffer as accelerated 3D (VC4) looks to be very 32 bit only. Indeed, the Pi3 is 32 bit everything except the CPU. Mate is installed but not configured as you don't get /home Make a normal user, and configure Mate to runt at the startx command. Oracle Java (arm64) installs to /opt but you can't have it because of the licence. icedtea:7 builds with gcj-5.4.0 icedtea:8 builds with icedtea:7 Thunderbird is fragile. You must add a mail account to it the first time it is run or it segfaults. To recover, delete its profile. sdlmame works. You must provide your own ROMs. Have fun. Post in Alternative Architectures on the Gentoo Forums for suport, make it clear its 64 bit Pi3. There is no harm in PMing NeddySeagon to make sure I don't miss your post but I don't do PM support. I don't support systemd ever, at all.