The release of kernel source codes is important for manufacturers, developers and the public alike. They are important for manufacturers as they allow manufacturers to abide by the terms of the open source nature of android. All android manufacturers who make use of a Linux based solution are expected to release their source code as part of the GPLv2. Likewise, it is important for developers as it is the release of this code that starts the aftermarket of developing for that particular device. As such, once the kernel code is released, ROM developers can start their understanding of what's included and see what they can do with the code. Likewise, it is important for the general public as it is this releasing of code that starts the ability for the public to choose between the various developed options which emerge from the code being made public.
Xiaomi is one of the companies who are expected to release the source code for their devices. However, they have not exactly been the quickest at making available their code. In fact. in recent times, they have been under somewhat pressure to release the code for certain devices. This culminated at the start of December when Hugo Barra finally confirmed that Xiaomi will release the code for the Xiaomi Redmi 1S and the Xiaomi Mi4. In terms of a timeframe, Barra stated the Redmi 1S would see its kernel code released before the end of December and the Mi4 code would be released before the end of Q1.
Well, it seems Xiaomi likes waiting to the very last moment to comply with their own promises. The December promised release of the Redmi 1S source code was released on the very last day of the month. Likewise, Xiaomi have now released the Mi4 kernel source code on the last day of Q1. That said, as well as releasing the source code for the Mi3 rather late, Xiaomi have compensated by also releasing the kernel code for the Mi4 and Mi Note as well. So, if you have been waiting on the source code for any of these devices, and particular for the Mi3, then you can now download the code by clicking the source link below.