This dual-boot kernel for the S7 was developed by XDA Forum Member hal_2000 with the help of XDA Senior Member irfanbagus, who brought dual-boot support to the Galaxy Y earlier this year. It is basically the stock 22.214.171.124-ideos Froyo kernel, with no additions other than dual-boot features. Your device must have the stock kernel in order to go ahead with the process. The complete process involves installing this kernel and preparing your SD card to run the second ROM.
For more details and to get on with dual-booting, head over to the forum thread.