Read the final value of the MACHINEOVERRIDES variable - linux

Question

During the porting of the layer for my SoM from the pyro branch to the dunfell one, I've encountered some problems related to the COMPATIBLE_MACHINE list in my recipes (BitBake says that there is no recipe compatible with my machine).
In order to further investigate this issue, I tried to read the actual value of the MACHINEOVERRIDES variable using the bitbake -e command. However, I don't think this list is complete, because watching the bitbake -e output I can see that there are other variable expansions which are used to form the value of the general OVERRIDES variable.
This is the output of the bitbake -e | grep OVERRIDES command run from my build environment:
# $DISTROOVERRIDES [3 operations]
DISTROOVERRIDES="fslc"
# $FILESOVERRIDES [2 operations]
# "${TRANSLATED_TARGET_ARCH}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}"
# [doc] "A subset of OVERRIDES used by the OpenEmbedded build system for creating FILESPATH."
# "${TRANSLATED_TARGET_ARCH}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}"
FILESOVERRIDES="arm:isiot:armv7ve:use-mainline-bsp:isiot-geamx6ul:fslc"
# $MACHINEOVERRIDES [14 operations]
# "PRISTINE_MACHINEOVERRIDES"
MACHINEOVERRIDES="isiot:armv7ve:use-mainline-bsp:isiot-geamx6ul"
# $MACHINEOVERRIDES_EXTENDER_FILTER_OUT
MACHINEOVERRIDES_EXTENDER_FILTER_OUT=" imx mx6 mx6q mx6dl mx6sx mx6sl mx6sll mx6ul mx6ull mx7 mx7d mx7ulp mx8 mx8qm mx8mm mx8mn mx8mq mx8qxp "
# $MACHINEOVERRIDES_EXTENDER_FILTER_OUT_use-mainline-bsp
MACHINEOVERRIDES_EXTENDER_FILTER_OUT_use-mainline-bsp=" imx mx6 mx6q mx6dl mx6sx mx6sl mx6sll mx6ul mx6ull mx7 mx7d mx7ulp mx8 mx8qm mx8mm mx8mn mx8mq mx8qxp "
# $MACHINEOVERRIDES_EXTENDER_mx25
MACHINEOVERRIDES_EXTENDER_mx25="use-mainline-bsp"
# $MACHINEOVERRIDES_EXTENDER_mx6dl
MACHINEOVERRIDES_EXTENDER_mx6dl="imxfbdev:imxpxp:imxipu:imxvpu:imxgpu:imxgpu2d:imxgpu3d:imxepdc"
# $MACHINEOVERRIDES_EXTENDER_mx6q
MACHINEOVERRIDES_EXTENDER_mx6q="imxfbdev:imxipu:imxvpu:imxgpu:imxgpu2d:imxgpu3d"
# $MACHINEOVERRIDES_EXTENDER_mx6sl
MACHINEOVERRIDES_EXTENDER_mx6sl="imxfbdev:imxpxp:imxgpu:imxgpu2d:imxepdc"
# $MACHINEOVERRIDES_EXTENDER_mx6sll
MACHINEOVERRIDES_EXTENDER_mx6sll="imxfbdev:imxpxp:imxepdc"
# $MACHINEOVERRIDES_EXTENDER_mx6sx
MACHINEOVERRIDES_EXTENDER_mx6sx="imxfbdev:imxpxp:imxgpu:imxgpu2d:imxgpu3d"
# $MACHINEOVERRIDES_EXTENDER_mx6ul
MACHINEOVERRIDES_EXTENDER_mx6ul="imxfbdev:imxpxp"
# $MACHINEOVERRIDES_EXTENDER_mx6ull
MACHINEOVERRIDES_EXTENDER_mx6ull="imxfbdev:imxpxp:imxepdc"
# $MACHINEOVERRIDES_EXTENDER_mx7d
MACHINEOVERRIDES_EXTENDER_mx7d="imxfbdev:imxpxp:imxepdc"
# $MACHINEOVERRIDES_EXTENDER_mx7ulp
MACHINEOVERRIDES_EXTENDER_mx7ulp="imxfbdev:imxpxp:imxgpu:imxgpu2d:imxgpu3d"
# $MACHINEOVERRIDES_EXTENDER_mx8mm
MACHINEOVERRIDES_EXTENDER_mx8mm="imxdrm:imxvpu:imxgpu:imxgpu2d:imxgpu3d"
# $MACHINEOVERRIDES_EXTENDER_mx8mn
MACHINEOVERRIDES_EXTENDER_mx8mn="imxdrm:imxgpu:imxgpu3d"
# $MACHINEOVERRIDES_EXTENDER_mx8mq
MACHINEOVERRIDES_EXTENDER_mx8mq="imxdrm:imxvpu:imxgpu:imxgpu3d"
# $MACHINEOVERRIDES_EXTENDER_mx8qm
MACHINEOVERRIDES_EXTENDER_mx8qm="imxdrm:imxdpu:imxgpu:imxgpu2d:imxgpu3d"
# $MACHINEOVERRIDES_EXTENDER_mx8qxp
MACHINEOVERRIDES_EXTENDER_mx8qxp="imxdrm:imxdpu:imxgpu:imxgpu2d:imxgpu3d"
# $OVERRIDES [2 operations]
# "${TARGET_OS}:${TRANSLATED_TARGET_ARCH}:pn-${PN}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}:${CLASSOVERRIDE}${LIBCOVERRIDE}:forcevariable"
# [doc] "BitBake uses OVERRIDES to control what variables are overridden after BitBake parses recipes and configuration files."
# "${TARGET_OS}:${TRANSLATED_TARGET_ARCH}:pn-${PN}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}:${CLASSOVERRIDE}${LIBCOVERRIDE}:forcevariable"
OVERRIDES="linux-gnueabi:arm:pn-defaultpkgname:isiot:armv7ve:use-mainline-bsp:isiot-geamx6ul:fslc:class-target:libc-glibc:forcevariable"
# $PRISTINE_MACHINEOVERRIDES [13 operations]
# rename from MACHINEOVERRIDES machine-overrides-extender.bbclass:49 [machine_overrides_extender_handler]
PRISTINE_MACHINEOVERRIDES="mx6:mx6ul:isiot:armv7ve:imx:use-mainline-bsp:isiot-geamx6ul"
# $SRC_URI_OVERRIDES_PACKAGE_ARCH
overrides = d.getVar('OVERRIDES').split(':')
msg = 'Recipe %s has PN of "%s" which is in OVERRIDES, this can result in unexpected behaviour.' % (d.getVar("FILE"), pn)
compat_machines = (d.getVar('MACHINEOVERRIDES') or "").split(":")
# unless the package sets SRC_URI_OVERRIDES_PACKAGE_ARCH=0
override = d.getVar('SRC_URI_OVERRIDES_PACKAGE_ARCH')
overrides = (":" + (d.getVar("FILESOVERRIDES") or "")).split(":")
overrides = localdata.getVar("OVERRIDES", False) + ":virtclass-multilib-" + multilib
localdata.setVar("OVERRIDES", overrides)
overrides = d.getVar("OVERRIDES").split(":")
machine_overrides = (d.getVar('PRISTINE_MACHINEOVERRIDES') or '').split(':')
machine_overrides_filter_out += (d.getVar('MACHINEOVERRIDES_EXTENDER_FILTER_OUT_%s' % override) or '').split()
extender = d.getVar('MACHINEOVERRIDES_EXTENDER_%s' % override)
# so we can reprocess OVERRIDES if/as/when needed.
d.renameVar("MACHINEOVERRIDES", "PRISTINE_MACHINEOVERRIDES")
d.setVar("MACHINEOVERRIDES", "${#machine_overrides_extender(d)}")
localdata.setVar('OVERRIDES', pkg)
localdata.setVar('OVERRIDES', localdata.getVar('OVERRIDES') + ':' + pkg)
overrides = localdata.getVar("OVERRIDES", False) + ":virtclass-multilib-" + item
localdata.setVar("OVERRIDES", overrides)
localdata.setVar('OVERRIDES', d.getVar("OVERRIDES", False) + ":" + pkg)
Is there a way to get the value of MACHINEOVERRIDES and OVERRIDES variables after those operations occur?
# so we can reprocess OVERRIDES if/as/when needed.
d.renameVar("MACHINEOVERRIDES", "PRISTINE_MACHINEOVERRIDES")
d.setVar("MACHINEOVERRIDES", "${#machine_overrides_extender(d)}")
localdata.setVar('OVERRIDES', pkg)
localdata.setVar('OVERRIDES', localdata.getVar('OVERRIDES') + ':' + pkg)
overrides = localdata.getVar("OVERRIDES", False) + ":virtclass-multilib-" + item
localdata.setVar("OVERRIDES", overrides)
localdata.setVar('OVERRIDES', d.getVar("OVERRIDES", False) + ":" + pkg)
Thanks.

Answer 1

bitbake -e already shows you the variables after the operations.
MACHINEOVERRIDES="isiot:armv7ve:use-mainline-bsp:isiot-geamx6ul" and
OVERRIDES="linux-gnueabi:arm:pn-defaultpkgname:isiot:armv7ve:use-mainline-bsp:isiot-geamx6ul:fslc:class-target:libc-glibc:forcevariable"
bitbake -e first shows you how many operations act on a variable e.g. # $MACHINEOVERRIDES [14 operations] and where they are coming from and after that the expanded value.
You could use bitbake -e | less to browse the output instead of grepping it.

Answer 2

You can simply use :
bitbake -e <package_name> | grep ^MACHINEOVERRIDES=
bitbake -e <package_name> | grep ^OVERRIDES=