support incremental updates of boot image
Modify applypatch to be able to write MTD partitions as well as read
them. Make applypatch save a backup copy of the contents of an MTD
partition it reads in cache, to be used in case an update is
interrupted while writing back to MTD. Modify OTA package creation
script to send boot image updates in patch form.
diff --git a/tools/applypatch/applypatch.h b/tools/applypatch/applypatch.h
index 041ac2e..e0320fb 100644
--- a/tools/applypatch/applypatch.h
+++ b/tools/applypatch/applypatch.h
@@ -38,6 +38,11 @@
// and use it as the source instead.
#define CACHE_TEMP_SOURCE "/cache/saved.file"
+// When writing to an MTD partition, we first put the output in this
+// temp file, then copy it to the partition once the patching is
+// finished (and the target sha1 verified).
+#define MTD_TARGET_TEMP_FILE "/tmp/mtd-temp"
+
// applypatch.c
size_t FreeSpaceForFile(const char* filename);