cd poky
source oe-init-build-env
mkdir -p manual_layer/conf

cat > manual_layer/conf/layer.conf << "EOF"
BBPATH .= ":${LAYERDIR}"
BBFILES += "${LAYERDIR}/*.bb"
EOF

cat > manual_layer/hello.bb << "EOF"
LICENSE = "MIT"
DESCRIPTION = "Prints Hello World"
PN = 'hello'
PV = '1'

python do_build() {
   bb.plain("********************");
   bb.plain("*                  *");
   bb.plain("*  Hello, World!   *");
   bb.plain("*                  *");
   bb.plain("********************");
}

do_build[nostamp]="1"

EOF

# Manually added the layer to conf/bblayers.conf

bitbake hello
Loading cache: 100% |##################################################################| Time: 0:00:00
Loaded 1299 entries from dependency cache.
NOTE: Resolving any missing task queue dependencies

Build Configuration:
BB_VERSION           = "1.44.0"
BUILD_SYS            = "x86_64-linux"
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "x86_64-poky-linux"
MACHINE              = "qemux86-64"
DISTRO               = "poky"
DISTRO_VERSION       = "3.0.1"
TUNE_FEATURES        = "m64 core2"
TARGET_FPU           = ""
meta
meta-poky
meta-yocto-bsp
manual_layer         = "zeus:cf92a2d567260b91a259652bad0ecd790750f710"

Initialising tasks: 100% |#############################################################| Time: 0:00:00
Sstate summary: Wanted 20 Found 20 Missed 0 Current 55 (100% match, 100% complete)
NOTE: Executing Tasks
NOTE: Setscene tasks completed
NOTE: Tasks Summary: Attempted 468 tasks of which 467 didn't need to be rerun and all succeeded.