Gentoo on Radxa X4 N100 SBC with RP2040 built in

[brendlefly62]

I had some questions along the way, but figured them out using forum posts and other references. So instead of posting questions to the forum, I can now post this link to Gentoo Wiki -- https://wiki.gentoo.org/wiki/User:Brendlefly62/Radxa_x4_N100_sbc_with_RP2040

which now documents Gentoo installation on Radxa's X4 single board computer (SBC), which has a form factor almost identical to Raspberry Pi 5, but sports a low-power quad core Intel N100 cpu (x86_64) and has a Raspberry Pi RP2040 microcontroller (arm v6) built in, for control of the board's 40 x GPIO pin header

This installation features --

• LUKS encrypted rootfs layout on 128G NVMe stick
  
• Gentoo "hardened plasma" profile
  
• Custom kernel from gentoo-sources-6.12.16
  
• Setup of crossdev toolchain arm-none-eabi for the RP2040
  
• Installation and demonstration of Raspberry Pi's pico-sdk and pico-examples
  
• Revision, recompilation, and installation of custom demo "blink.c" program for the RP2040 microcontroller