linux_banner as "Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n";, printed in init/main.c (start_kernel). UTS_RELEASE, LINUX_COMPILE_BY etc. are defined in include/generated/compile.h. const char linux_proc_banner[] =
"%s version %s"
" (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ")"
" (" LINUX_COMPILER ") %s\n";
linux_banner is defined in init/version-timestamp.c which is included (#include) from init/version.c. BUILD_SALT and BUILT_LTO_INFO.