❯ bitbake-getvar MACHINE_FEATURES -r core-image-base
#
# $MACHINE_FEATURES [5 operations]
#   append /home/user/Workspace/Yocto/healthpi/sources/meta-raspberrypi/conf/machine/raspberrypi4-64.conf:7
#     "pci"
#   append /home/user/Workspace/Yocto/healthpi/sources/meta-raspberrypi/conf/machine/include/rpi-base.inc:91
#     "apm usbhost keyboard vfat ext2 screen touchscreen alsa bluetooth wifi sdio ${@bb.utils.contains('DISABLE_VC4GRAPHICS', '1', '', 'vc4graphics', d)}"
#   set /home/user/Workspace/Yocto/healthpi/sources/poky/meta/conf/documentation.conf:283
#     [doc] "Specifies the list of hardware features the MACHINE supports."
#   set? /home/user/Workspace/Yocto/healthpi/sources/poky/meta/conf/bitbake.conf:833
#     ""
#   append utils.py:129 [features_backfill]
#     " qemu-usermode"
# pre-expansion value:
#   " pci apm usbhost keyboard vfat ext2 screen touchscreen alsa bluetooth wifi sdio ${@bb.utils.contains('DISABLE_VC4GRAPHICS', '1', '', 'vc4graphics', d)} qemu-usermode"
MACHINE_FEATURES=" pci apm usbhost keyboard vfat ext2 screen touchscreen alsa bluetooth wifi sdio vc4graphics qemu-usermode"
❯ bitbake-getvar VC4DTBO -r core-image-base
#
# $VC4DTBO
#   set? /home/user/Workspace/Yocto/healthpi/sources/meta-raspberrypi/conf/machine/raspberrypi4-64.conf:27
#     "vc4-kms-v3d"
VC4DTBO="vc4-kms-v3d"
❯ bitbake-getvar MACHINE_EXTRA_IMAGE_INSTALL -r core-image-base
#
# $MACHINE_EXTRA_IMAGE_INSTALL
#   [no history recorded]
#
#   "None"