JP2006126994A - Incircuit emulator, debug device and debug system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a debug system for reducing possibility that a program which is the object of security protection is acquired. <P>SOLUTION: The debug system 1 is provided with a debug device 2 and an incircuit emulator 3. The debug device 2 is provided with a communication processing part 21, an authentication processing part 22, a program storing part 23 and a debug processing part 24. The incircuit emulator 3 is provided with a communication processing part 31, an authentication processing part 32, a program storing part 33 and a CPU core part 34. When authentication succeeds between the authentication processing part 22 and the authentication processing part 32, the communication processing part 21 transmits firmware which is the object of security protection and a user program which is not the object of security protection to the incircuit emulator 3, and when authentication is not successful, the communication processing part 21 transmits the user program. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-circuit emulator, a debugging device used by being connected to the in-circuit emulator, and a debugging system including them.

Conventionally, techniques for increasing the confidentiality of programs have been used in microprocessors and debugging devices (see, for example, Patent Document 1).
Patent Document 1 discloses a storage unit for storing an encryption key for decrypting an encryption range of a program in which at least one range is encrypted, and an encryption key from the storage unit by determining the encryption range of the program. And a decryption unit that decrypts the encryption range of the program using the encryption key extracted by the determination unit, and the decryption unit decrypts the encryption range. A microprocessor is provided that includes an encryption unit that encrypts at least one range of the program when the program is output to the outside.
Patent Document 1 discloses a debugging device that debugs a program output from the microprocessor, and includes a debugger storage unit that stores an encryption key for decrypting the encryption range of the program, A debugger determination unit that determines the encryption range and extracts the encryption key from the debugger storage unit, and a debugger decryption unit that decrypts the encryption range of the program using the encryption key extracted by the debugger determination unit A debugging device characterized by this is posted.

  However, in the technique disclosed in Patent Document 1, since the program encrypted by the encryption unit is output from the microprocessor to the debugger device, the communication signal between the microprocessor and the debugger device is monitored, so that the encryption is performed. It will be possible to obtain a customized program. In view of the possibility that the encryption may be decrypted or the encryption key may be obtained later, it is not desirable to obtain an encrypted program.

JP 2003-140763 A

  Therefore, in view of the above points, a first object of the present invention is to provide an in-circuit emulator that can further reduce the possibility of obtaining a program that is subject to confidentiality. The second object of the present invention is to provide such a debugging device. The third object of the present invention is to provide such a debugging system.

  In order to solve the above problems, an in-circuit emulator according to a first aspect of the present invention stores a first program that is a confidentiality target and / or a second program that is not a confidentiality target. A CPU core unit for executing the first and / or second program according to an instruction from the outside, the first and / or second program received from the outside, and written in the program storage unit, When an instruction to read a part or all of the program is received from the outside, the part or whole of the first program is not read from the program storage unit, and a part or whole of the second program is instructed to be read. Communication processing unit for reading a part or all of the second program from the program storage unit and transmitting it to the outside when received from the outside Comprising a.

  The in-circuit emulator according to the second aspect of the present invention further includes an authentication processing unit for performing authentication processing with the outside in the in-circuit emulator according to the first aspect of the present invention.

  An in-circuit emulator according to a third aspect of the present invention is an in-circuit emulator according to the first aspect of the present invention, in which a communication processing unit responds to an external call in a general in-circuit emulator. Communicating with the outside using a first communication command that is used or a second communication command that is not used in a general in-circuit emulator.

  In the in-circuit emulator according to the first to third aspects, the communication processing unit decrypts the first program and writes it to the program storage unit when the first program received from the outside is encrypted. It's also good.

  The debugging device according to the first aspect of the present invention is a debugging device that is used by being connected to an in-circuit emulator, and is a first program that is a confidentiality target and / or a second that is not a confidentiality target. An in-circuit emulator according to the first aspect of the present invention when connected to a program storage unit for storing a program and the in-circuit emulator according to the first aspect of the present invention And a communication processing unit for transmitting the second program to the in-circuit emulator when connected to an in-circuit emulator other than the in-circuit emulator according to the first aspect of the present invention, and an in-circuit emulator Debug processing section for performing debug processing by sending and receiving data to and from Comprising a.

  A debugging device according to a second aspect of the present invention is a debugging device that is used by being connected to an in-circuit emulator, and is a first program that is a security target and / or a second that is not a security target. When the authentication processing unit for performing authentication processing between the program storage unit for storing the program and the in-circuit emulator according to the second aspect of the present invention, and the authentication processing by the authentication processing unit, The first and second programs are judged to be connected to the in-circuit emulator according to the second aspect of the present invention, and the first and second programs are transmitted to the in-circuit emulator according to the second aspect of the present invention. If the authentication process cannot be performed, it is connected to an in-circuit emulator other than the in-circuit emulator according to the second aspect of the present invention. A communication processing unit for determining that the second program is transmitted to the in-circuit emulator, and a debug processing unit for performing a debugging process by transmitting / receiving data to / from the in-circuit emulator. .

  A debugging device according to a third aspect of the present invention is a debugging device that is used by being connected to an in-circuit emulator, and is a first program that is a confidentiality target and / or a second that is not a confidentiality target. When a call is made to the in-circuit emulator using the program storage unit for storing the program and the second communication command and there is a response, the in-circuit emulator according to the third aspect of the present invention is connected. The first and second programs are transmitted to the in-circuit emulator according to the third aspect of the present invention using the second communication command, and are transmitted to the in-circuit emulator using the second communication command. If the call is made and there is no response, an insulator other than the in-circuit emulator according to the third aspect of the present invention Data is transmitted / received between the in-circuit emulator and a communication processing unit for determining that it is connected to the kit emulator and transmitting the second program to the in-circuit emulator using the first communication command A debugging processing unit for performing debugging processing.

  In the debugging device according to the first to third aspects, the first program stored in the program storage unit may be encrypted.

  A debugging system according to the first aspect of the present invention includes an in-circuit emulator according to the first aspect of the present invention and a debugging device according to the first aspect of the present invention.

  A debugging system according to the second aspect of the present invention includes an in-circuit emulator according to the second aspect of the present invention and a debugging device according to the second aspect of the present invention.

  A debugging system according to the third aspect of the present invention includes an in-circuit emulator according to the third aspect of the present invention and a debugging device according to the third aspect of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the same component, it has shown with the same reference number.
FIG. 1 is a diagram showing an outline of a debugging system according to the first embodiment of the present invention. As shown in FIG. 1, the debug system 1 includes a debug device 2 and an in-circuit emulator (ICE) 3. The debugging device 2 and the in-circuit emulator 3 are connected via a communication cable C. The in-circuit emulator 3 is used by being coupled to an evaluation board, a product board, or the like.

The debugging device 2 includes a communication processing unit 21, an authentication processing unit 22, a program storage unit 23, and a debugging processing unit 24.
The communication processing unit 21 performs communication processing with the in-circuit emulator 3 and the authentication processing unit 22 performs authentication processing with the in-circuit emulator 3.

The program storage unit 23 is, for example, a recording medium such as a hard disk drive, and stores a firmware file that is provided by a hardware vendor or the like and is a security target, and a user program file that is created by an end user and is not a security target. Yes. Note that the contents of the firmware file may be encrypted. The file name of the firmware file may be a name that is difficult for a person in charge of debugging the user program to recognize that the file is a firmware file (for example, the extension is “dll”). . This makes it more difficult for the person in charge of debugging to know the contents of the firmware in the debug device 2.
The debug processing unit 24 receives the operation of the person in charge of debugging, transmits data corresponding to the operation to the in-circuit emulator 3, and displays the data received from the in-circuit emulator 3. Note that the debug processing unit 24 may have a compile function, an assemble function, and the like for creating or updating a user program file.
The debugging device 3 can be configured by a computer and a program, for example.

The in-circuit emulator 3 includes a communication processing unit 31, an authentication processing unit 32, a program storage unit 33, and a CPU core unit 34.
The communication processing unit 31 performs communication processing with the debug device 2 and the authentication processing unit 32 performs authentication processing with the debug device 2.

The program storage unit 33 is, for example, a memory or the like, and has a firmware storage area that is an address space for storing firmware and a user program storage area that is an address space for storing user programs. The firmware and the user program stored in the program storage unit 23 of the debugging device 2 are transferred and written to the firmware storage area and the user program storage area by the communication processing unit 31, respectively. The communication processing unit 31 reads out the user program in the user program storage area and transmits it to the debugging apparatus 2 in accordance with the instruction from the debugging apparatus 2, but in order to keep the firmware confidential, The firmware is not read out. Note that a general in-circuit emulator reads any program without distinguishing between the firmware and the user program. In this respect, the in-circuit emulator 3 is different from a general in-circuit emulator.
The CPU core unit 34 executes the firmware and / or user program stored in the program storage unit 33 step by step or continuously in accordance with an instruction from the debug device 2. Note that the communication processing unit 31 can write to and read from various registers in the CPU core unit 34 in accordance with instructions from the debug device 2.

Next, the operation of the debug system 1 will be described. FIG. 2 is a flowchart showing the program transfer process of the debug system 1. Hereinafter, the program transfer process of the debug system 1 will be described with reference to FIG.
First, the authentication processing unit 22 of the debug device 2 performs an authentication process (step S11). In this authentication process, the in-circuit emulator currently connected to the debugging device 2 is the in-circuit emulator 3 according to the present embodiment, or a general in-circuit emulator other than the in-circuit emulator 3 according to the present embodiment. Is done to identify. Here, as shown in FIG. 1, since the in-circuit emulator 3 according to this embodiment is connected to the debugging device 2, the authentication processing unit 22 of the debugging device 2 and the authentication processing unit 32 of the in-circuit emulator 3 are connected. Authentication processing is performed between them (steps S11 and S21). In this authentication process, the authentication processing unit 32 of the in-circuit emulator 3 transmits the product model number, product serial number, other IDs, etc. to the authentication processing unit 22 of the debugging device 2, and the authentication processing unit of the debugging device 2. 22 may identify whether the currently connected in-circuit emulator is the in-circuit emulator 3 according to the present embodiment using the received product model number or the like.

  When the authentication with the in-circuit emulator 3 can be performed (step S12), the communication processing unit 21 of the debug device 2 transmits the firmware to the in-circuit emulator 3 (step S13), and the communication processing unit of the in-circuit emulator 3 31 writes the received firmware in the firmware storage area of the program storage unit 33 (step S22). If the contents of the firmware file in the program storage unit 23 of the debug device 2 are encrypted, the communication processing unit 31 of the in-circuit emulator 3 decrypts and writes it in the firmware storage area.

  When the authentication with the in-circuit emulator 3 cannot be performed (step S12) or when the transmission of the firmware is finished (step S13), the communication processing unit 21 of the debug device 2 sends the user program to the in-circuit emulator 3. Then, the communication processing unit 31 of the in-circuit emulator 3 writes the received user program in the user program storage area of the program storage unit 33 (step S23).

The firmware transmission (step S13) may be automatically performed without waiting for an instruction from the person in charge of debugging. As described above, the file name of the firmware file is set to a name that is difficult for the person in charge of debugging to recognize that it is a firmware file, and the firmware is automatically transmitted without waiting for instructions from the person in charge of debugging. If so, it is possible to conceal the existence of the firmware itself and the transfer itself to the in-circuit emulator 3 from the end user.
Further, if the transmission of firmware is automatically performed without waiting for an instruction from the person in charge of debugging, it is possible to make it more difficult to obtain the firmware by monitoring the signal on the communication cable C.
On the other hand, the transmission of the user program (step S14) may be performed after waiting for an instruction from the person in charge of debugging.

  As described above, the firmware and the user program are transferred from the debug device 2 to the in-circuit emulator 3. Thereafter, the person in charge of debugging can cause the CPU core unit 34 to execute the firmware and the user program by operating the debug processing unit 24 and giving an instruction to the in-circuit emulator 3.

  By the way, in a debugging operation, a person in charge of debugging may try to refer to a program in the program storage unit 33 of the in-circuit emulator 3. FIG. 3 is a flowchart showing a program reference process for referring to a program in the program storage unit 33 of the in-circuit emulator 3 in such a case. Hereinafter, the program reference processing of the debug system 1 will be described with reference to FIG.

First, when the person in charge of debugging inputs a desired address, the debug processing unit 24 of the debugging device 2 transmits the input address to the in-circuit emulator 3 via the communication processing unit 21 (step S31). The person in charge of debugging may input a single address, or may specify an address range.
The communication processing unit 31 of the in-circuit emulator 3 checks whether the received address indicates the firmware storage area or the user program storage area (step S41), and the received address indicates the user program storage area In this case, the program stored at the received address is transmitted to the debug device 2 (step S42). If the received address indicates the firmware storage area, the process is terminated.
When receiving the program, the debugging device 2 displays or stores the received program (step S32).

  As described above, according to the debug system 1, when the address input by the person in charge of debugging points to the user program storage area, the in-circuit emulator 3 transmits the program to the debug device 2. When the address input by the in-circuit emulator indicates the firmware storage area, the in-circuit emulator 3 does not transmit the program to the debugging device 2, so that the person in charge of debugging cannot view the firmware and keep the firmware confidential. Can do.

Further, as shown in FIG. 4A, a debugging person who intends to view the firmware connects the debugging device 2 to a general in-circuit emulator 4 other than the in-circuit emulator 3 according to the present embodiment. Then, as shown in FIG. 4B, it is conceivable that one end of the communication cable C is disconnected from the debug device 2 and connected to a general debug device 5 other than the debug device 2 according to the present embodiment.
As described above, the general in-circuit emulator, unlike the in-circuit emulator 3 according to the present embodiment, reads out any program without distinguishing between the firmware and the user program. However, as shown in FIG. 4A, when the debugging device 2 according to the present embodiment and a general in-circuit emulator 4 are connected, authentication cannot be performed, so the firmware is transferred from the debugging device 2 to the in-circuit emulator 4. It is not transferred (see steps S11, S21, S12, and S13 in FIG. 2). Therefore, even if the person in charge of debugging connects the in-circuit emulator 4 and the debug device 5 and operates the debug device 5 as shown in FIG. 4B, the firmware is not transferred to the in-circuit emulator 4. Therefore, the firmware cannot be browsed.

Further, a debugging person who intends to view the firmware connects the debugging device 2 to the in-circuit emulator 3 as shown in FIG. 5A, and then, as shown in FIG. It can be considered that one end of the communication cable C is disconnected from the debugging device 2 and connected to a general debugging device 5 other than the debugging device 2 according to the present embodiment.
As shown in FIG. 5A, when the debugging device 2 and the in-circuit emulator 3 are connected, the firmware is transferred from the debugging device 2 to the in-circuit emulator 3. However, even if the person in charge of debugging connects the in-circuit emulator 4 and the debugging device 5 and designates an address in the firmware storage area as shown in FIG. Since the program is not read out (see steps S41 and S42 in FIG. 3), the firmware cannot be browsed.

  Next, a second embodiment of the present invention will be described. FIG. 6 is a diagram showing an outline of a debugging system according to the second embodiment of the present invention. As shown in FIG. 6, the debug system 6 includes a debug device 7 and an in-circuit emulator (ICE) 8. The debugging device 7 and the in-circuit emulator 8 are connected via a communication cable C.

The debugging device 7 includes a program storage unit 23, a debug processing unit 24, and a communication processing unit 71.
The communication processing unit 71 is a general communication command used between a general in-circuit emulator and a debugging device or a special communication command unique to the present embodiment that is not used between a general in-circuit emulator and a debugging device. To communicate with the in-circuit emulator.

The in-circuit emulator 8 includes a program storage unit 33, a CPU core unit 34, and a communication processing unit 81.
The communication processing unit 81 communicates with the debug device using a general communication command or a special communication command.

Next, the operation of the debug system 6 will be described. FIG. 7 is a flowchart showing the program transfer process of the debug system 6. Hereinafter, the program transfer process of the debug system 6 will be described with reference to FIG.
First, the communication processing unit 71 of the debugging device 7 calls the in-circuit emulator 8 using a special communication command (step S51). When a general in-circuit emulator is connected to the debugging device 7, the general in-circuit emulator cannot interpret the special communication command and therefore cannot respond to the call from the debugging device 7. On the other hand, the communication processing unit 81 of the in-circuit emulator 8 according to the present embodiment can interpret both general communication commands and special communication commands. Here, since the in-circuit emulator 8 is connected to the debug device 7, the in-circuit emulator 8 responds to the debug device 7 using a special communication command (step S61).

When there is a response from the in-circuit emulator (step S52), the communication processing unit 71 of the debugging device 7 determines that the in-circuit emulator 8 is connected to the debugging device 7, and the special communication command is used for the subsequent communication. (Step S53), the firmware is transmitted using the special communication command (step S54), and the user program is transmitted using the special communication command (step S55). The communication processing unit 81 of the in-circuit emulator 8 writes the firmware received using the special communication command into the firmware storage area of the program storage unit 33 (step S62), and the user program received using the special communication command is stored in the program storage unit. 33 is written into the user program storage area 33 (step S63).
If the contents of the firmware file in the program storage unit 23 of the debug device 7 are encrypted, the communication processing unit 81 of the in-circuit emulator 8 decrypts and writes it in the firmware storage area. The firmware transmission (step S54) may be automatically performed without waiting for an instruction from the person in charge of debugging. On the other hand, the transmission of the user program (step S55) may be performed after an instruction from the person in charge of debugging.

  On the other hand, when there is no response from the in-circuit emulator (step S52), the communication processing unit 71 of the debug device 7 determines that a general in-circuit emulator is connected to the debug device 7, and performs subsequent communication. The general communication command is used (step S56), and the user program is transmitted using the general communication command (step S57). Note that the transmission of the user program (step S57) may be performed after waiting for an instruction from the person in charge of debugging.

  As described above, the firmware and the user program are transferred from the debug device 7 to the in-circuit emulator 8. Thereafter, the person in charge of debugging can cause the CPU core unit 34 to execute the firmware and the user program by giving an instruction to the in-circuit emulator 8 from the debug processing unit 24.

  By the way, in the debugging work, the person in charge of debugging may try to refer to the program in the program storage unit 33 of the in-circuit emulator 8. In this case, similarly to the debugging system 1 described above, the communication processing unit 81 of the in-circuit emulator 8 causes the user program to be stored in the debugging device 7 when the address input by the person in charge of the debugging indicates the user program storage area. If the address input by the person in charge of debugging points to the firmware storage area, the firmware may not be transmitted to the debugging device 7 (see FIG. 3). As a result, the person in charge of debugging cannot view the firmware, and the confidentiality of the firmware can be maintained.

As described above, a debugging person who intends to view the firmware connects the debugging device 7 to a general in-circuit emulator other than the in-circuit emulator 8 according to the present embodiment, and then It is conceivable that one end of the communication cable C is disconnected from the debugging device 7 and connected to a general debugging device other than the debugging device 7 according to this embodiment (see FIGS. 4A and 4B).
As described above, the general in-circuit emulator, unlike the in-circuit emulator 8 according to the present embodiment, reads out any program without distinguishing between the firmware and the user program. However, when the debugging device 7 according to the present embodiment and a general in-circuit emulator are connected, the firmware is not transferred from the debugging device 7 to the general in-circuit emulator (Steps S52 and S56 in FIG. 7). (See S57). Therefore, even if the person in charge of debugging connects the general in-circuit emulator and the general debug device and operates the general debug device, the firmware is not transferred to the general in-circuit emulator. Cannot be viewed.

Further, a debugging person who intends to view the firmware connects the debugging device 7 to the in-circuit emulator 8, and then disconnects one end of the communication cable C from the debugging device 7, and the debugging device 7 according to the present embodiment. It is conceivable to connect to a general debugging device other than (see FIGS. 5A and 5B).
When the debugging device 7 and the in-circuit emulator 8 are connected, the firmware is transferred from the debugging device 7 to the in-circuit emulator 8 using a special communication command (see step S54 in FIG. 7). However, even if the person in charge of debugging connects the in-circuit emulator 8 and a general debugging device and designates an address in the firmware storage area, the in-circuit emulator 8 does not read the program in the firmware storage area. The firmware cannot be browsed.

  The present invention relates to an in-circuit emulator, a debugging device used by being connected to the in-circuit emulator, and a debugging system including them.

1 is a diagram showing an outline of a debugging system according to a first embodiment of the present invention. The flowchart which shows operation | movement of the debug system 1 of FIG. The flowchart which shows operation | movement of the debug system 1 of FIG. The figure which connected the debugging apparatus 2 of FIG. 1 to the general in-circuit emulator. The figure which connected the in-circuit emulator 3 of FIG. 1 to the general debugging apparatus. The figure which shows the outline | summary of the debug system which concerns on the 2nd Embodiment of this invention. 7 is a flowchart showing the operation of the debug system 6 of FIG.

Explanation of symbols

1, 6 Debug system 2, 5, 7 Debug device 3, 4, 8 In-circuit emulator, 21, 31, 41, 71, 81 Communication processing unit, 22, 32 Authentication processing unit, 23, 33, 42 Program storage Part, 24 debug processing part, 34, 43 CPU core part

Claims (11)

A program storage unit for storing a first program that is subject to confidentiality and / or a second program that is not subject to confidentiality;
A CPU core unit for executing the first and / or second program according to an external instruction;
When the first and / or second program is received from the outside and written to the program storage unit, and a read instruction for part or all of the first program is received from the outside, the program storage unit One part of the second program from the program storage unit when an instruction to read part or all of the second program is received from the outside without reading part or all of the first program. A communication processing unit for reading out all or part of the data and transmitting the same to the outside;
In-circuit emulator equipped with.   The in-circuit emulator according to claim 1, further comprising an authentication processing unit for performing authentication processing with the outside.   In response to a call from the outside, the communication processing unit externally uses a first communication command used in a general in-circuit emulator or a second communication command not used in a general in-circuit emulator. The in-circuit emulator according to claim 1, which communicates with the in-circuit emulator.   The communication processing unit decrypts the first program and writes the first program in the program storage unit when the first program received from the outside is encrypted. The in-circuit emulator described in 1. A debugging device connected to an in-circuit emulator,
A program storage unit for storing a first program that is subject to confidentiality and / or a second program that is not subject to confidentiality;
When connected to the in-circuit emulator according to claim 1, the first and second programs are transmitted to the in-circuit emulator according to claim 1, and sent to an in-circuit emulator other than the in-circuit emulator according to claim 1. A communication processing unit for transmitting the second program to the in-circuit emulator when connected;
A debug processing unit for performing debug processing by transmitting and receiving data to and from an in-circuit emulator;
A debugging device comprising: A debugging device connected to an in-circuit emulator,
A program storage unit for storing a first program that is subject to confidentiality and / or a second program that is not subject to confidentiality;
An authentication processing unit for performing authentication processing with the in-circuit emulator according to claim 2;
3. When authentication processing by the authentication processing unit is completed, it is determined that the authentication processing unit is connected to the in-circuit emulator according to claim 2, and the first and second programs are transmitted to the in-circuit emulator according to claim 2. When the authentication processing by the authentication processing unit cannot be performed, it is determined that the second processing program is connected to an in-circuit emulator other than the in-circuit emulator according to claim 2, and the second program is transmitted to the in-circuit emulator. A communication processing unit for
A debug processing unit for performing debug processing by transmitting and receiving data to and from an in-circuit emulator;
A debugging device comprising: A debugging device connected to an in-circuit emulator,
A program storage unit for storing a first program that is subject to confidentiality and / or a second program that is not subject to confidentiality;
The first and second programs are determined to be connected to the in-circuit emulator according to claim 3 when the second communication command is used to call the in-circuit emulator and there is a response. Is transmitted to the in-circuit emulator according to claim 3 using the second communication command, the in-circuit emulator is called using the second communication command, and no response is received. A communication processing unit for determining that the second program is connected to an in-circuit emulator other than the in-circuit emulator and transmitting the second program to the in-circuit emulator using the first communication command;
A debug processing unit for performing debug processing by transmitting and receiving data to and from an in-circuit emulator;
A debugging device comprising:   The debugging device according to claim 5, wherein the first program stored in the program storage unit is encrypted. An in-circuit emulator according to claim 1 or 4,
The debugging device according to claim 5 or 8,
A debugging system comprising: An in-circuit emulator according to claim 2 or 4,
A debugging device according to claim 6 or 8,
A debugging system comprising: An in-circuit emulator according to claim 3 or 4,
A debugging device according to claim 7 or 8,
A debugging system comprising:

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