I've just released version 1.8.0 of the live-USB image of Gentoo Linux for the B3 on GitHub (here). The kernel has been upgraded to version 4.3.0. All included packages are up-to-date against the Gentoo tree, as of 8 November 2015 (and so, of course, shellshock, heartbleed and Ghost fixes have been applied). A full package list may be viewed here.
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 383MiB; 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).
Some other changes in this release:
- Fixed install_on_sda.sh and install_on_sda_gpt.sh scripts (they were not copying the /opt directory), and migrated these to the gentoo-b3 overlay;
- Explicitly specified PermitRootLogin yes in /etc/ssh/sshd_config (as not allowed by default in openssh v7).