Samsung firmware update I9100XXMS1 is now available and it brings Android 4.1.2 Jelly Bean for Galaxy S2 I9100 devices. This update is currently rolling out to Galaxy S2 Poland users and is also available for download. So, if you have not received the update via OTA or Samsung Kies so far, you can install it manually using Odin.
Samsung started rolling out Jelly Bean 4.1.2 Galaxy S2 update later last month and devices in different regions continue to receive the update since then. Spain Galaxy S2 I9100 was the first device to receive the update, followed by I9100T and I9100G. Samsung Canada I9100M and Israel Galaxy S2 phones received the update last month.
Version: Android 4.1.2 Jelly Bean JZO54K
Download & Install I9100 XXMS1 (Galaxy S2 Poland Jelly Bean Update)
Download the firmware zip file: I9100XXMS1_I9100OXAMS1_XEO.zip
Once you have downloaded the firmware, you can install it on your Galaxy S2 using Odin. Here is the link to step by step guide: how to install stock firmware using Odin.