Re: flash-kernel: handle DTBs in vendor subdir

[Martin Michlmayr <tbm@cyrius.com>]

* Ian Campbell <ijc@debian.org> [2016-07-31 10:20]:
> I've attached the two patches I had sitting in my branch here, they
> look sensible but I honestly can't remember what state they are in.
> 
> AFAICT the main difference is that they preserve the directory layout
> rather than collapsing it. Not sure there is any particular reason to
> favour either way of doing it so feel free to either ignore or pickup
> these patches.

The boot script looks for dtbs/${fk_kvers}/${fdtfile} and $fdtfile
doesn't contain the vendor subdir, so I think this approach is wrong.

> One thing my patches handles which I'm not sure yours does is the pre-
> subdir-transition versions on ARM64, which my commit log says happened
> in v3.19-rc1. That might be important for backports and/or upgrades.

I looked at your other patch and I like the approach since it supports
the old and new way.  Personally I found search_for_dtb_file_in_prefix
a bit hard to read and wonder if a simple 'find' might do.

What do you think of this approach?  This no longer requires the
vendor subdir in DTB-Id.  I think this is better since e.g. the RPi3
has the same device tree on 32 and 64 bit and I assume one will be in
a vendor subdir whereas the other won't be.

Any comments?

diff --git a/README b/README
index 02ba3fd..9458a23 100644
--- a/README
+++ b/README
@@ -115,9 +115,13 @@ The supported fields are:
   This option is ignored if a DTB is to be appended, via either DTB-Append or
   DTB-Append-From.
 
-* DTB-Id: (optional) specifies the name of the DTB file for this device. If
-  the value begins with a `!' then the field is a script which should be run.
-  The script must produce the DTB filename (and nothing else) on stdout.
+* DTB-Id: (optional) specifies the name of the DTB file for this device
+  relative to the kernel package DTB dir or /etc/flash-kernel/dtbs.
+  It's not necessary to specify the directory if the DTB is in a vendor
+  subdirectory as flash-kernel will search for the filename in
+  subdirectories.  If the value begins with a `!' then the field is a script
+  which should be run.  The script must produce the DTB filename (just the
+  filename, without a vendor subdirectory) on stdout (and nothing else).
 
 * DTB-Append: (optional) when yes the DTB specified by DTB-Id will be appended
   to the kernel image.
diff --git a/functions b/functions
index 0f597b8..f008515 100644
--- a/functions
+++ b/functions
@@ -241,6 +241,12 @@ get_dtb_name() {
 		;;
 	esac
 	if [ -n "$dtb_name" ] ; then
+		# DTBs on arm64 are stored in subdirs for each vendor; strip
+		# the dir away (in case someone specified it, although it's
+		# not needed).
+		# The DTB will be stored in /boot/dtbs/$kvers/ without
+		# additional subdirs.
+		dtb_name=$(basename $dtb_name)
 		echo "DTB: $dtb_name" >&2
 	fi
 }
@@ -558,11 +564,11 @@ find_dtb_file() {
 		echo "$dtb_name"
 		;;
 	*)
-		if [ -e "/etc/flash-kernel/dtbs/$dtb_name" ] ; then
-			echo "/etc/flash-kernel/dtbs/$dtb_name"
-		else
-			echo "/usr/lib/linux-image-$kvers/$dtb_name"
+		local dtb=$(find /etc/flash-kernel/dtbs -name $dtb_name 2>/dev/null | head -n 1)
+		if [ -z "$dtb" ]; then
+			dtb=$(find /usr/lib/linux-image-$kvers -name $dtb_name 2>/dev/null | head -n 1)
 		fi
+		echo $dtb
 		;;
 	esac
 }
@@ -597,8 +603,8 @@ handle_dtb() {
 			rmdir --ignore-fail-on-non-empty /boot/dtbs
 		fi
 	else
-		if [ -e $dtb ]; then
-			echo "Installing $dtb_name into /boot/dtbs/$kvers/$dtb_name" >&2
+		if [ -e "$dtb" ]; then
+			echo "Installing $dtb into /boot/dtbs/$kvers/$dtb_name" >&2
 			mkdir -p /boot/dtbs/$kvers/
 			cp "$dtb" "/boot/dtbs/$kvers/$dtb_name.new"
 			backup_and_install \

-- 
Martin Michlmayr
http://www.cyrius.com/