Hi Nathan,
On 08/07/2018 04:59 AM, Nathan Rossi wrote:
On 7 August 2018 at 07:16, Jaewon Lee <[email protected]> wrote:
Hi Nathan,
What do you think about adding support for dts include files as well (.dtsi)?
Hi Jaewon,
Device tree include files already work with the implementation in this
patch. The default include path is the same as the path of the dts
files, so if you use "/include/ "<dtsi>.dtsi";" (dtc) or "#include
<dtsi.dtsi>" (preprocessor) it will search within the DT_FILES_PATH
(which is WORKDIR by default) and then the KERNEL_INCLUDE paths.
Though if the dtsi is in another path you can add it to DT_INCLUDE,
and it will be searched.
If i'm understanding correctly, this flow just supports compiling a dts
file that has a plugin tag (it can include dtsi files)
in short I can't compile the dtsi file itself to a dtbo
Does this cover the support you are after or is there another
configuration you would like it to support?
Yes for us, if dt overlays are enabled, we don't include a dtsi in the
base dts and compile that dtsi separately as a dtbo which is loaded later.
so would be great to loop through all dtsi files as well and compile if
it has a plugin tag.
Your thoughts?
Thanks,
Jaewon
Thanks,
Nathan
Thanks,
Jaewon
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Nathan
Rossi
Sent: Thursday, August 2, 2018 1:55 AM
To: [email protected]
Subject: [OE-core] [PATCH] devicetree.bbclass: User/BSP device tree source
compilation class
This bbclass implements the device tree compilation for user provided device
trees. In order to use this class, it should be inherited in a BSP recipe which
provides the sources. The default setup enables inclusion of kernel device tree
sources (though can be disabled by the recipe by overriding DT_INCLUDE or
KERNEL_INCLUDE).
This provides an additional mechanism for BSPs to provide device trees and
device tree overlays for their target machines. Whilst still enabling access to
the kernel device trees for base SoC includes and headers.
This approach to providing device trees has benefits for certain use cases over
patching the device trees into the kernel source.
* device trees are separated from kernel source, allows for selection of kernel
and or kernel versions without needing to explicitly patch the kernel (or
appending to the kernel recipes).
* providing device trees from separate sources, from the layer, generated by
the recipe or other recipes.
This class also implements some additional features that are not available in
the kernel-devicetree flow. This includes population of device tree blobs into
the sysroot which allows for other recipes to consume built dtbs (e.g. U-Boot
with EXT_DTB compilation), device tree overlay compilation and customizing DTC
compilation args (boot cpu/padding/etc.).
Signed-off-by: Nathan Rossi <[email protected]>
Acked-by: Martin Hundebøll <[email protected]>
---
In addition to this patch I have written some documentation for the Yocto BSP
guide that covers details about both methods.
The meta-xilinx layer has a recipe (device-tree.bb) that behaves exactly like
this class for some time. It has been very useful for out-of-kernel device tree
compilation as well as for a mechanism so that users of Xilinx SoCs can provide
their customizations (FPGA devices) and board specific configuration. This
compilation flow also makes sense for other BSPs, which is the reason for
creating this bbclass for common shared use by other BSPs.
Examples of this classes usage can be seen for meta-xilinx:
https://github.com/nathanrossi/meta-xilinx/blob/nrossi/devicetree-classify/meta-xilinx-bsp/recipes-bsp/device-tree/device-tree.bb
---
meta/classes/devicetree.bbclass | 140 ++++++++++++++++++++++++++++++++
1 file changed, 140 insertions(+)
create mode 100644 meta/classes/devicetree.bbclass
diff --git a/meta/classes/devicetree.bbclass b/meta/classes/devicetree.bbclass
new file mode 100644 index 0000000000..dbc83f2a1d
--- /dev/null
+++ b/meta/classes/devicetree.bbclass
@@ -0,0 +1,140 @@
+# This bbclass implements device tree compliation for user provided
+device tree # sources. The compilation of the device tree sources is
+the same as the kernel # device tree compilation process, this includes
+being able to include sources # from the kernel such as soc dtsi files
+or header files such as gpio.h. In # addition to device trees this
+bbclass also handles compilation of device tree # overlays.
+#
+# The output of this class behaves similar to how
+kernel-devicetree.bbclass # operates in that the output files are installed
into /boot/devicetree.
+# However this class on purpose separates the deployed device trees
+into the # 'devicetree' subdirectory. This prevents clashes with the
+kernel-devicetree # output. Additionally the device trees are populated
+into the sysroot for # access via the sysroot from within other recipes.
+
+SECTION ?= "bsp"
+
+# The default inclusion of kernel device tree includes and headers
+means that # device trees built with them are at least GPLv2 (and in
+some cases dual # licensed). Default to GPLv2 if the recipe does not specify a
license.
+LICENSE ?= "GPLv2"
+LIC_FILES_CHKSUM ?=
"file://${COMMON_LICENSE_DIR}/GPL-2.0;md5=801f80980d171dd6425610833a22dbe6"
+
+INHIBIT_DEFAULT_DEPS = "1"
+DEPENDS += "dtc-native"
+
+inherit deploy kernel-arch
+
+COMPATIBLE_MACHINE ?= "^$"
+
+PACKAGE_ARCH = "${MACHINE_ARCH}"
+
+SYSROOT_DIRS += "/boot/devicetree"
+FILES_${PN} = "/boot/devicetree/*.dtb /boot/devicetree/*.dtbo"
+
+S = "${WORKDIR}"
+B = "${WORKDIR}/build"
+
+# Default kernel includes, these represent what are normally used for
+in-kernel # sources.
+KERNEL_INCLUDE ??= " \
+ ${STAGING_KERNEL_DIR}/arch/${ARCH}/boot/dts \
+ ${STAGING_KERNEL_DIR}/arch/${ARCH}/boot/dts/* \
+ ${STAGING_KERNEL_DIR}/scripts/dtc/include-prefixes \
+ "
+
+DT_INCLUDE[doc] = "Search paths to be made available to both the device tree
compiler and preprocessor for inclusion."
+DT_INCLUDE ?= "${DT_FILES_PATH} ${KERNEL_INCLUDE}"
+DT_FILES_PATH[doc] = "Defaults to source directory, can be used to select dts files
that are not in source (e.g. generated)."
+DT_FILES_PATH ?= "${S}"
+
+DT_PADDING_SIZE[doc] = "Size of padding on the device tree blob, used as extra
space typically for additional properties during boot."
+DT_PADDING_SIZE ??= "0x3000"
+DT_RESERVED_MAP[doc] = "Number of reserved map entires."
+DT_RESERVED_MAP ??= "8"
+DT_BOOT_CPU[doc] = "The boot cpu, defaults to 0"
+DT_BOOT_CPU ??= "0"
+
+DTC_FLAGS ?= "-R ${DT_RESERVED_MAP} -p ${DT_PADDING_SIZE} -b ${DT_BOOT_CPU}"
+DTC_PPFLAGS ?= "-nostdinc -undef -D__DTS__ -x assembler-with-cpp"
+DTC_OFLAGS ?= "-@ -H epapr"
+
+python () {
+ if d.getVar("KERNEL_INCLUDE"):
+ # auto add dependency on kernel tree, but only if kernel include paths
+ # are specified.
+ d.appendVarFlag("do_compile", "depends", "
+virtual/kernel:do_configure") }
+
+def expand_includes(varname, d):
+ import glob
+ includes = set()
+ # expand all includes with glob
+ for i in (d.getVar(varname) or "").split():
+ for g in glob.glob(i):
+ if os.path.isdir(g): # only add directories to include path
+ includes.add(g)
+ return includes
+
+def devicetree_source_is_overlay(path):
+ # determine if a dts file is an overlay by checking if it uses "/plugin/;"
+ with open(path, "r") as f:
+ for i in f:
+ if i.startswith("/plugin/;"):
+ return True
+ return False
+
+def devicetree_compile(dtspath, includes, d):
+ import subprocess
+ dts = os.path.basename(dtspath)
+ dtname = os.path.splitext(dts)[0]
+ bb.note("Processing {0} [{1}]".format(dtname, dts))
+
+ # preprocess
+ ppargs = d.getVar("BUILD_CPP").split()
+ ppargs += (d.getVar("DTC_PPFLAGS") or "").split()
+ for i in includes:
+ ppargs.append("-I{0}".format(i))
+ ppargs += ["-o", "{0}.pp".format(dts), dtspath]
+ bb.note("Running {0}".format(" ".join(ppargs)))
+ subprocess.run(ppargs, check = True)
+
+ # determine if the file is an overlay or not (using the preprocessed file)
+ isoverlay = devicetree_source_is_overlay("{0}.pp".format(dts))
+
+ # compile
+ dtcargs = ["dtc"] + (d.getVar("DTC_FLAGS") or "").split()
+ if isoverlay:
+ dtcargs += (d.getVar("DTC_OFLAGS") or "").split()
+ for i in includes:
+ dtcargs += ["-i", i]
+ dtcargs += ["-o", "{0}.{1}".format(dtname, "dtbo" if isoverlay else "dtb")]
+ dtcargs += ["-I", "dts", "-O", "dtb", "{0}.pp".format(dts)]
+ bb.note("Running {0}".format(" ".join(dtcargs)))
+ subprocess.run(dtcargs, check = True)
+
+python devicetree_do_compile() {
+ includes = expand_includes("DT_INCLUDE", d)
+ listpath = d.getVar("DT_FILES_PATH")
+ for dts in os.listdir(listpath):
+ if not dts.endswith(".dts"):
+ continue # skip non-.dts files
+ dtspath = os.path.join(listpath, dts)
+ devicetree_compile(dtspath, includes, d) }
+
+devicetree_do_install() {
+ for DTB_FILE in `ls *.dtb *.dtbo`; do
+ install -Dm 0644 ${B}/${DTB_FILE} ${D}/boot/devicetree/${DTB_FILE}
+ done
+}
+
+devicetree_do_deploy() {
+ for DTB_FILE in `ls *.dtb *.dtbo`; do
+ install -Dm 0644 ${B}/${DTB_FILE} ${DEPLOYDIR}/devicetree/${DTB_FILE}
+ done
+}
+addtask deploy before do_build after do_install
+
+EXPORT_FUNCTIONS do_compile do_install do_deploy
+
--
2.18.0
--
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