including all powerpc kernels makes the netinst huge, so include only those

base-installer can install

debian/changelog

@@ -51,8 +51,8 @@ debian-cd (2.2.17) UNRELEASED; urgency=low
     - Add wireless-tools to generate_d-i+k_list
     - Remove the old partitioner from the CD for i386. (This should also be
       done for other arches for which it is not default)
-    - Include every available powerpc kernel on the CD, which is perhaps
-      better than a random selection of two obscure subarches..
+    - Include all the powerpc kernels that d-i's base-installer currently
+      could try to install on the CD.
     - Try to include some sparc kernels on the CD; it's probably better than
       including none..
   * Steve Langasek

tools/generate_di+k_list

@@ -77,9 +77,14 @@ cat >> debian-installer+kernel << EOF
 #ifdef ARCH_powerpc
 EOF
 
-/bin/sed -n 's/Package: \(kernel-image-.*-powerpc.*\)$/\1/p' \
-  $MIRROR/dists/$CODENAME/main/binary-powerpc/Packages \
-  >> debian-installer+kernel
+# Only include powerpc kernels that d-i base-installer installs.
+for subarch in powerpc-pmac powerpc-small-pmac powerpc-prep powerpc-chrp \
+               powerpc-chrp-rs6k apus; do
+	sed -n 's/Package: \(kernel-image-.*-.*\)$/\1/p' \
+		$MIRROR/dists/$CODENAME/main/binary-powerpc/Packages \
+		| grep -- "-$subarch$" | sort -n | tail -n 1 \
+                >> debian-installer+kernel
+done
 
 cat >> debian-installer+kernel << EOF
 #endif