I've just released version 1.4.0 of the live-USB image of Gentoo Linux for the B3 on GitHub (here). The kernel has been upgraded to version 4.0.1 (and also includes the PCIe/WiFi patch discussed in this thread). All included packages are up-to-date against the Gentoo tree, as of 2 May 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 356MiB; 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 specify initial network settings, so you can ssh in once booted, and 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:
- The workaround to enable net-misc/dhcpcd to compile with v4 kernel headers has been implemented (please see here);
- Scripts have been supplied (as part of the image) to simplify HDD installation, for those who wish to do so (this remains entirely optional). They are /root/install_on_sda.sh and /root/install_on_sda_gpt.sh.
Have fun ^-^
PS: if you'd like to try v4 of the Linux kernel, but would rather use a binary distro, then please take a look at my Arch Linux live-USB for the B3, available here.