pub fn boot_banner()Expand description
Print the ASCII banner at the very top of a boot run. Called once
from rbnx boot before any [ ssss.mmm ] line. Layout mimics the
kernel’s “Linux version …” splash: name + version + git sha,
builder, build time, compiler, target. All facts come from build.rs
via compile-time env vars; missing values gracefully render as
“unknown” so a tarball / sandboxed build still prints a banner.