From 7eec2b56f54c778d5bd6e7aea49ee03e3b76e769 Mon Sep 17 00:00:00 2001
From: Peter Robinson <pbrobinson@gmail.com>
Date: Fri, 22 Jan 2021 20:36:23 +0000
Subject: [PATCH v2] Add support for compressing firmware in copy-firmware.sh

As of kernel 5.3 there's initial support for loading compressed firmware.
At this stage the only supported compression methis is "xz -C crc32" but
this option brings significant benefits.

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
---

v2: quote filename for xz command

 Makefile         |  4 ++++
 copy-firmware.sh | 47 +++++++++++++++++++++++++++++++----------------
 2 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/Makefile b/Makefile
index e1c362f..9a48471 100644
--- a/Makefile
+++ b/Makefile
@@ -11,3 +11,7 @@ check:
 install:
 	mkdir -p $(DESTDIR)$(FIRMWAREDIR)
 	./copy-firmware.sh $(DESTDIR)$(FIRMWAREDIR)
+
+installcompress:
+	mkdir -p $(DESTDIR)$(FIRMWAREDIR)
+	./copy-firmware.sh -C $(DESTDIR)$(FIRMWAREDIR)
diff --git a/copy-firmware.sh b/copy-firmware.sh
index 9b46b63..0dd2e5c 100755
--- a/copy-firmware.sh
+++ b/copy-firmware.sh
@@ -6,6 +6,7 @@
 
 verbose=:
 prune=no
+compress=no
 
 while test $# -gt 0; do
     case $1 in
@@ -19,6 +20,11 @@ while test $# -gt 0; do
             shift
             ;;
 
+        -C | --compress)
+            compress=yes
+            shift
+            ;;
+
         *)
             if test "x$destdir" != "x"; then
                 echo "ERROR: unknown command-line options: $@"
@@ -31,40 +37,49 @@ while test $# -gt 0; do
     esac
 done
 
+if test "x$compress" = "xyes"; then
+    cmpxtn=.xz
+    grep '^File:' WHENCE | sed -e's/^File: *//g' -e's/"//g' | while read f; do
+       test -f "$f" || continue
+       $verbose "compressing $f"
+       xz -C crc32 "$f"
+    done
+fi
+
 grep '^File:' WHENCE | sed -e's/^File: *//g' -e's/"//g' | while read f; do
-    test -f "$f" || continue
-    $verbose "copying file $f"
-    install -d $destdir/$(dirname "$f")
-    cp -d "$f" $destdir/"$f"
+    test -f "$f$cmpxtn" || continue
+    $verbose "copying file $f$cmpxtn"
+    install -d $destdir/$(dirname "$f$cmpxtn")
+    cp -d "$f$cmpxtn" $destdir/"$f$cmpxtn"
 done
 
 grep -E '^Link:' WHENCE | sed -e's/^Link: *//g' -e's/-> //g' | while read f d; do
-    if test -L "$f"; then
-        test -f "$destdir/$f" && continue
-        $verbose "copying link $f"
-        install -d $destdir/$(dirname "$f")
+    if test -L "$f$cmpxtn"; then
+        test -f "$destdir/$f$cmpxtn" && continue
+        $verbose "copying link $f$cmpxtn"
+        install -d $destdir/$(dirname "$f$cmpxtn")
         cp -d "$f" $destdir/"$f"
 
         if test "x$d" != "x"; then
-            target=`readlink "$f"`
+            target=`readlink "$f$cmpxtn"`
 
             if test "x$target" != "x$d"; then
                 $verbose "WARNING: inconsistent symlink target: $target != $d"
             else
                 if test "x$prune" != "xyes"; then
-                    $verbose "WARNING: unneeded symlink detected: $f"
+                    $verbose "WARNING: unneeded symlink detected: $f$cmpxtn"
                 else
-                    $verbose "WARNING: pruning unneeded symlink $f"
-                    rm -f "$f"
+                    $verbose "WARNING: pruning unneeded symlink $f$cmpxtn"
+                    rm -f "$f$cmpxtn"
                 fi
             fi
         else
-            $verbose "WARNING: missing target for symlink $f"
+            $verbose "WARNING: missing target for symlink $f$cmpxtn"
         fi
     else
-        $verbose "creating link $f -> $d"
-        install -d $destdir/$(dirname "$f")
-        ln -sf "$d" "$destdir/$f"
+        $verbose "creating link $f$cmpxtn -> $d$cmpxtn"
+        install -d $destdir/$(dirname "$f$cmpxtn")
+        ln -sf "$d$cmpxtn" "$destdir/$f$cmpxtn"
     fi
 done
 
-- 
2.29.2