Research On Key Technology Of Large-scale Fpga Bitstream File Reverse

As Field Programmable Gate Array(FPGA)is gradually applied in military,infrastructure and other important fields,it is facing increasingly serious security threats.Especially in the great power confrontation,FPGA as the core device of all kinds of weapons and equipment,once attacked by hardware Trojan and other means,will lead to very serious consequences.At present,the protection measures against hardware Trojan mainly focus on the higher level of circuit design,such as netlist level or code level.However,it is difficult to obtain circuit design source code without destroying the chip,but it is relatively easy to extract bitstream files.Therefore,some researchers have proposed a complete bitstream reverse framework,which can reverse from bitstream files to netlist files and then to code files.However,it currently supports fewer chip models and does not support reverse of core resources.In view of the above situation,this thesis proposes a mapping relational database measurement method based on command line and Tcl and a code reverse method for hardcore resources under the existing bitstream reverse framework.The former is mainly applied to the netlist reverse process of Altera FPGA chip to improve the measurement efficiency and data integrity of mapping relational database.The latter is mainly applied to the code reverse process of Xilinx FPGA chip,which adds the function of reverse core resource to the extensible code reverse framework.The main research work of this thesis is as follows:(1)A mapping relational database measurement method based on command line and Tcl is proposed.Firstly,it introduces the three cornerstones of the reverse technology of FPGA netlist,including configuration file,netlist file and mapping relational database,and the existing measurement method of mapping relational database as well as the use of executable command line program and Tcl script in Quartus II software.In view of the existing database measurement method is mainly composed by manual operation,and has the shortcomings of low efficiency and time-sonsuming,the modified measurement method is proposed to run the whole measurement process automation using command line executable programs and combination of Tcl script,and to improve the efficiency of database measurement and data integrity.Finally,by loading the mapping relational database measured by the proposed method and the existing method into the reverse platform of netlist,and reversing the ISCAS '85 benchmark of combined circuit set and ISCAS' 89 benchmark of sequential circuit set,the correctness of the database measured by the proposed method is verified.(2)A code reverse method of the hardcore resources is proposed.The existing extensible code reverse framework and the underlying hardware architecture of hardcore resources including distributed RAM and shift register SRL are introduced.Then we discuss and choose to reverse hardcore in a primitive way,and expatiate the process of reverse method in detail.Finally,the hardcore code example provided by Xilinx is reversed by the code reverse platform which extends the hardcore reverse function.The correctness and practicability of the reverse method are verified and the application scope of the code reverse platform is broadened.In addition,an application of code reverse technology is briefly introduced,that is,the conversion between FPGA and ASIC netlist.