Adjust generic BSPs to support the inheritance model

Each inherited BSP must set a MACHINEOVERRIDES and PACKAGE_EXTRA_ARCHS to
ensure that various overrides can be set along the way.  The general format
for this is (in the caller):

require conf/machine/<inherited machine>.conf

The callee is responsible for adding to the MACHINEOVERRIDES and
PACKAGE_EXTRA_ARCHS.  It does this by setting the following at the beginning
and end of the file, respectively.

MACHINEOVERRIDES =. "${@['', '<machine>:']['<machine>' != '${MACHINE}']}"
...
...
PACKAGE_EXTRA_ARCHS_append = "${@['', ' <machine_arch>']['<machine>' != '${MACHINE}']}"

where <machine> is the <machine>.conf file the line appears in;
<machine_arch> is the <machine>.replace('-', '_') (matching MACHINE_ARCH) if
the machine file was used by itself.

The MACHINEOVERRIDES uses =. or .= everywhere in the Yocto Project.  Doing it
via =. in the load order ensures in order evaluation.

PACKAGE_EXTRA_ARCHS is set via 'append', but needs to be the last operation
to ensure that we are always added AFTER anything we include along the way.
Effectively this is a late binding evaluation.

Signed-off-by: Mark Hatle <mark.hatle@xilinx.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/meta-xilinx-core/conf/machine/versal-generic.conf b/meta-xilinx-core/conf/machine/versal-generic.conf
index a5d99b75..3509d8c4 100644
--- a/meta-xilinx-core/conf/machine/versal-generic.conf
+++ b/meta-xilinx-core/conf/machine/versal-generic.conf
@@ -7,6 +7,10 @@ USE_BOARD = "${@"conf/machine/include/xilinx-board-pre.inc" if d.getVar("BOARD")
 require ${USE_BOARD}
 unset USE_BOARD
 
+#### Preamble
+MACHINEOVERRIDES =. "${@['', 'versal-generic:']['versal-generic' != '${MACHINE}']}"
+#### Regular settings follow
+
 require conf/machine/include/soc-versal.inc
 require conf/machine/include/machine-xilinx-default.inc
 require conf/machine/include/machine-xilinx-qemu.inc
@@ -89,6 +93,10 @@ QB_PLM_OPT = " \
     "
 QB_OPT_APPEND:append:qemuboot-xilinx = " -plm-args '${QB_PLM_OPT}'"
 
+#### No additional settings should be after the Postamble
+#### Postamble
+PACKAGE_EXTRA_ARCHS:append = "${@['', ' versal_generic']['versal-generic' != "${MACHINE}"]}"
+
 # Deprecated board config
 USE_BOARD = "${@"conf/machine/include/xilinx-board-post.inc" if d.getVar("BOARD") or d.getVar("BOARD_VARIANT") else ""}"
 require ${USE_BOARD}