Samsung Galaxy S Duos (GT-S7568) Firmware Overview
What is the latest GT-S7568 firmware?
S7568ZMAMH2, released February 18, 2014 with Android 4.0. The archive holds 2 official builds across 1 region (CSC). Each one is the full stock ROM (flash file) for Odin, not an OTA patch.
Is the Samsung Galaxy S Duos still getting updates?
Most likely not: there has been no new firmware since February 2014, so Android 4.0 is the last version this model got. The final builds below are still the best choice for a clean reinstall.
All GT-S7568 firmware builds
Older GT-S7568 Builds (Archive)
2 earlier builds from the samdb.org catalogue. They are not in the download list above; the link searches for the build on the partner site.
How to Flash GT-S7568 Firmware
Put the Samsung Galaxy S Duos into Download Mode, load the BL, AP, CP and CSC files into Odin on a Windows PC and press Start. Use HOME_CSC to keep your data, CSC for a full wipe.