apply sdcaard:update.zip后出现如下问题：
E：Can't open /cache/recovery/command
--Install from sdcard...
Finding update package...
Opening update package...
Verifying update package...
Installing update...
assert failed:file_getprop("/system/build.prop"."ro.build.fingerprint") == "google/passion/passion/mahimahi:2.1-update1/ERE2//24178:user/release-kyes" || "ro.build.fingerprint") == "google/passion/passion/mahimahi:2.2/FRF50/38042:user/release-keys"
E:Error in /sdcard/update.zip
(status 7)
Installation aborted.
杯具得不行，根据找不到从ERD56C升级到FRF50或其它版本的包。。。。
ERD56C升级至ERE27:
http://forum.xda-developers.com/showthread.php?p=9518576
ERE27升级至ERF50:
http://www.android-hk.com/news/nexus-one-manually-update-android-2-2/