/sys/lib/dist/mkfile: add pi.img target for raspi sdcard image

sys/lib/dist/mkfile

@@ -21,6 +21,34 @@ cd:V:	/tmp/9front.386.iso.gz
 	mv $target.$pid.pc.iso $target
 	}
 
+%.pi.img:
+	@{
+	objtype=arm
+	bootcode=/sys/src/boot/bcm/^(bootcode.bin fixup_cd.dat start_cd.elf LICENCE.broadcom)
+	kernels=/n/src9/$objtype/^(9pi 9pi2)
+	> /env/config.txt {
+		echo '[pi0]'
+		echo 'kernel=9pi'
+		echo '[pi1]'
+		echo 'kernel=9pi'
+		echo '[pi2]'
+		echo 'kernel=9pi2'
+		echo '[pi3]'
+		echo 'kernel=9pi2'
+		echo 'core_freq=250'
+		echo '[all]'
+		echo 'gpu_mem=16'
+		echo 'enable_uart=1'
+	}
+	> /env/cmdline.txt {
+		echo 'console=0'
+	}
+	fatfiles=(/env/config.txt /env/cmdline.txt $bootcode $kernels)
+	mb=1919	# storage vendors idea of 2GB
+	mk $target.$pid.disk
+	mv $target.$pid.disk $target
+	}
+
 %.zynq.img:
 	@{
 	objtype=arm
@@ -72,9 +100,25 @@ cd:V:	/tmp/9front.386.iso.gz
 	disk/partfs -m /n/$s $target
 	d=/n/$s/sdXX
 	disk/mbr $d/data
-	disk/fdisk -baw $d/data
-	disk/prep -bw -a^(9fat nvram fs) $d/plan9
-	disk/format -d -r 2 $d/9fat $fatfiles
+	if(~ $target *.pi.img.*){
+		{
+			echo 'a p1 . .+100M'
+			echo 't p1 FAT32'
+			echo 'a p2 . $'
+			echo 't p2 PLAN9'
+			echo 'A p1'
+			echo 'p'
+			echo 'w'
+			echo 'q'
+		} | disk/fdisk -b $d/data
+		disk/prep -bw -a^(nvram fs) $d/plan9
+		disk/format -d $d/dos $fatfiles
+	}
+	if not {
+		disk/fdisk -baw $d/data
+		disk/prep -bw -a^(9fat nvram fs) $d/plan9
+		disk/format -d -r 2 $d/9fat $fatfiles
+	}
 	hjfs -f $d/fs -n $s -S -r
 	{
 		echo echo on