I've just released version 2.1.0 of the live-USB image of Gentoo Linux for the B3 on GitHub (here). All included packages are up-to-date against the Gentoo tree, as of 4 September 2018. A full package list may be viewed here, kernel config here. Gentoo profile 17.0 is used throughout. The kernel is 4.18.5 (and will update, just like userspace packages, whenever you run genup).
As before, you can burn the supplied image to a USB key (>=8GB, Lexar and SanDisk keys seem the most reliable) then boot your B3 from it, without affecting any installed (Excito) system on your B3's hard drive. (The compressed image is 364MiB; writing takes between 10 and 20 minutes, depending on your system.) You can even boot a diskless B3! No soldering, compilation or U-Boot flashing is required.
The live-USB may then be used as a rescue disk, to play with Gentoo Linux, or as the starting point to install Gentoo Linux on your B3's main hard drive. Any packages you install, or other changes you make, while running the live-USB are saved on the USB key, but do not affect your existing Excito system, so you can run Gentoo for a while, then reboot back into your Excito system and continue to use it as normal, then boot back into the USB at a later date - any changes you made will still be there when you do.
Full instructions are provided on the project's GitHub page (including how to install Gentoo on your B3's internal hard drive too, in case you want to do that).
Summary of changes wrt 2.0.1:
- The subscribed Gentoo binhost (automatically updated weekly) has been migrated to profile 17.0 (at https://isshoni.org/b3pie) (the binhost allows your B3 to perform fast updates via binary packages where possible, only falling back to local source-based compilation where necessary; using this facility is of course optional).
- As in the previous release, the binhost also provides an rsync mirror for the main gentoo repo, used to keep the B3's ebuild tree in lockstep with the build server, thereby preventing time-consuming local builds being initiated when large packages, such as sys-devel/gcc, update. However, as of 2.1.0, the Portage tree is validated using Gentoo's recently-introduced gemato digital signature check, rather than porthash (and accordingly, app-portage/b3-check-portage is not installed).
- The custom Gentoo profile used on the image (which supplies many of the default build settings, USE flags etc., required for Gentoo on the B3, keeping them in lockstep with the binhost), has changed, from gentoo-b3:default/linux/arm/13.0/armv5te/b3 to gentoo-b3:default/linux/arm/17.0/armv5te/b3. You can view this profile (provided via the gentoo-b3 overlay) here.
- A weekly cron job (/etc/cron.weekly/genup) has been installed, to automate the process of keeping your B3 up-to-date (this can be deleted if you prefer).
- All packages have been brought up to date against the Gentoo tree, as of 4 September 2018.
- As before, the kernel on the image is managed by a binary package (sys-kernel/gentoo-b3-kernel-bin), and so will (like userspace packages) be updated whenever you run genup. The shipped version is 4.18.5-gentoo-b3.
If you wish to manually upgrade from an existing 2.0.1 image (rather than using this 2.1.0 image directly), then please see my release notes here.
As an alternative to this live image, you might also want to check out Gordon's Bubbagen (here): this is also a profile 17.0 Gentoo system, but includes a nice port of Excito's GUI.
Have fun ^-^