devicetree.bbclass: don't pad DT overlays

By default the devicetree class adds padding to the generated .dtb
files, which can be needed by the bootloader. However it also pads
.dtbo files, which is not useful.

Don't apply padding to the overlay devicetrees.

To achieve this:

 * move "-p ${DT_PADDING_SIZE}" to a new variable, DTB_BFLAGS (B for
   "base")
 * add "-p 0" to DTC_OFLAGS to disable padding for overlays

Cc: Nathan Rossi <nathan@nathanrossi.com>
(From OE-Core rev: 678fe8c66b19f141f6869859cf365aec037e89d9)

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/meta/classes/devicetree.bbclass b/meta/classes/devicetree.bbclass
index dbc83f2a1d..8fe5a5ed79 100644
--- a/meta/classes/devicetree.bbclass
+++ b/meta/classes/devicetree.bbclass
@@ -55,9 +55,10 @@ 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_FLAGS ?= "-R ${DT_RESERVED_MAP} -b ${DT_BOOT_CPU}"
 DTC_PPFLAGS ?= "-nostdinc -undef -D__DTS__ -x assembler-with-cpp"
-DTC_OFLAGS ?= "-@ -H epapr"
+DTC_BFLAGS ?= "-p ${DT_PADDING_SIZE}"
+DTC_OFLAGS ?= "-p 0 -@ -H epapr"
 
 python () {
     if d.getVar("KERNEL_INCLUDE"):
@@ -106,6 +107,8 @@ def devicetree_compile(dtspath, includes, d):
     dtcargs = ["dtc"] + (d.getVar("DTC_FLAGS") or "").split()
     if isoverlay:
         dtcargs += (d.getVar("DTC_OFLAGS") or "").split()
+    else:
+        dtcargs += (d.getVar("DTC_BFLAGS") or "").split()
     for i in includes:
         dtcargs += ["-i", i]
     dtcargs += ["-o", "{0}.{1}".format(dtname, "dtbo" if isoverlay else "dtb")]