Support building boot images for eMMC devices.

[debian-xu4] / README

diff --git a/README b/README
index ef3febb274e96bab18691a647a9a74b24d86227e..0349694a8683b1e0485ea0b3128efe77a6869af7 100644 (file)
--- a/README
+++ b/README
@@ -5,7 +5,20 @@ The image is signed with my GnuPG key; you can find the key in the
 Debian keyring.
 
 The prebuilt images are made for 1GB cards, so they should fit onto
 Debian keyring.
 
 The prebuilt images are made for 1GB cards, so they should fit onto

-pretty much any modern SD card.
+pretty much any modern SD or MMC card. Root images built for SD cards
+will fit work on MMC devices but not the other way round (the prebuilt
+root images are for SD).
+
+If you want to update the boot partition of an eMMC device (where
+U-Boot lives), you will need to unlock it before Linux lets you
+write to it, e.g.:
+
+  echo 0 > /sys/block/mmcblk0boot0/force_ro
+
+SD cards do not have hardware partitions (U-Boot is stored on the same
+block device as everything else), so all you need to do is to decompress
+the image and dd it to the card.
+

 
 Prebuilt images: https://storage.sesse.net/debian-xu4/
 ODROID forum thread: http://forum.odroid.com/viewtopic.php?f=96&t=21256
 
 Prebuilt images: https://storage.sesse.net/debian-xu4/
 ODROID forum thread: http://forum.odroid.com/viewtopic.php?f=96&t=21256