Secure remote debugging of SoCs

1. A system on a chip (SoC), comprising:

an intellectual property (IP) block to produce an event;

a microcontroller to execute firmware comprising a network stack and a remote debugger program; and

a fabric coupled to the microcontroller and the IP block;

wherein the IP block is to transmit, over the fabric, information about the produced event to the microcontroller;

wherein the microcontroller is to use the network stack and the remote debugger program to provide the information about the produced event to a device external to the SoC; and

wherein the IP block comprises:

a virtual test access port (vTAP); and

a functional pipeline comprising:

a hardware processing module; and

a register.

2. The SoC of claim 1 , wherein the IP block is a processor.

3. The SoC of claim 1 , wherein the fabric is a sideband fabric.

4. The SoC of claim 1 , wherein the vTAP comprises:

a slave interface coupled to the fabric;

a master interface coupled to the fabric and to the functional pipeline; and

a decoder coupled to the slave interface and to the functional pipeline;

wherein the slave interface is to:

receive a command from the microcontroller via the fabric; and

transfer the command to the decoder;

wherein the decoder is to:

decode the command; and

transfer the decoded command to the functional pipeline;

wherein the functional pipeline is to:

execute the decoded command using the hardware processing module; and

update the register in response to the execution of the decoded command; and

wherein the master interface is to:

read contents of the register;

generate, based on the contents of the register, a response to the received command; and

transmit the generated response to the microcontroller via the fabric.

5. The SoC of claim 4 , wherein the microcontroller is to receive, via the remote debugger program and the network stack, the command from the device external to the SoC.

6. The SoC of claim 5 , further comprising:

a non-volatile memory, wherein the microcontroller is to record into the non-volatile memory:

the command received from the external device; and

the generated response corresponding to the received command.

7. The SoC of claim 1 , further comprising:

a plurality of field-programmable fuses (FPFs), wherein the microcontroller is to destroy a respective FPF in the plurality of FPFs in response to a corresponding command received by the microcontroller from the device external to the SoC;

wherein a respective FPF in the plurality of FPFs corresponds to a respective computing service offered by the SoC; and

wherein the SoC is to provide the respective computing service if the respective FPF is not destroyed.

8. The SoC of claim 7 , wherein a subset of FPFs in the plurality of FPFs corresponds to a computing service offered by the SoC, wherein the subset of FPFs has a cardinality of operational fuses, and wherein the cardinality has a parity; and

wherein the SoC is to provide the computing service only if the parity of the cardinality of the FPF subset is odd.

9. The SoC of claim 1 , further comprising:

a cryptographic key;

wherein the microcontroller is to use the cryptographic key to authenticate the firmware prior to execution of the firmware.

10. A method for remote debugging a system on a chip (SoC), the method comprising:

producing, by an intellectual property (IP) block, an event;

executing, by a microcontroller, a network stack and a remote debugging program;

transmitting, by the IP block to the microcontroller, information about the produced event, the transmitting performed over a fabric connecting the IP block and the microcontroller; and

providing, by the microcontroller using the network stack and the remote debugging program, the information about the produced event to a device external to the SoC;

wherein the IP block comprises:

a virtual test access port (vTAP); and

a functional pipeline comprising:

a hardware processing module; and

a register.

11. The method of claim 10 , wherein the IP block is a processor.

12. The method of claim 10 , wherein the fabric is a sideband fabric.

13. At least one non-transitory machine-readable medium comprising instructions which, when executed by a machine, cause the machine to:

produce, by an intellectual property (IP) block, an event;

execute, by a microcontroller, a network stack and a remote debugger program;

transmit, by the IP block to the microcontroller, information about the produced event, the transmission to be performed over a fabric, the fabric connected to the IP block and to the microcontroller; and

provide, by the microcontroller through use of the network stack and the remote debugger program, the information about the produced event to a device external to the SoC;

wherein the IP block comprises:

a virtual test access port (vTAP); and

a functional pipeline comprising:

a hardware processing module; and

a register.

14. The at least one non-transitory machine-readable medium of claim 13 , wherein the IP block is a processor.

15. The at least one non-transitory machine-readable medium of claim 13 , wherein the fabric is a sideband fabric.

16. The at least one non-transitory machine-readable medium of claim 13 , wherein the vTAP comprises:

a slave interface coupled to the fabric;

a master interface coupled to the fabric and to the functional pipeline; and

a decoder coupled to the slave interface and to the functional pipeline.

17. The at least one non-transitory machine-readable medium of claim 16 , further comprising instructions which, when executed by the machine, cause the machine to:

receive, by the slave interface, a command from the microcontroller via the fabric;

transfer, by the slave interface, the command to the decoder;

decode, by the decoder, the command;

transfer, by the decoder, the decoded command to the functional pipeline;

execute, by the functional pipeline, the decoded command, the execution performed by the hardware processing module;

update, by the functional pipeline, the register in response to the execution of the decoded command;

read, by the master interface, contents of the register;

generate, by the master interface based on the contents of the register, a response to the received command; and

transmit, by the master interface, the generated response to the microcontroller via the fabric.

18. The at least one non-transitory machine-readable medium of claim 17 , wherein the microcontroller is to receive, via the remote debugger program and the network stack, the command from the device external to the SoC.

19. The at least one non-transitory machine-readable medium of claim 18 , further comprising instructions which, when executed by the machine, cause the machine to:

record, by the microcontroller into a non-volatile memory:

the command received from the external device; and

the generated response corresponding to the received command.

20. The at least one machine-readable medium of claim 13 , wherein the SoC comprises:

a plurality of field-programmable fuses (FPFs);

wherein a respective FPF in the plurality of FPFs corresponds to a respective computing service offered by the SoC.

21. The at least one non-transitory machine-readable medium of claim 20 , further comprising instructions which, when executed by the machine, cause the machine to:

receive, by the microcontroller from the device external to the SoC, a respective command to destroy a respective FPF in the plurality of FPFs; and

destroy, by the microcontroller, the respective FPF in the plurality of FPFs.

22. The at least one non-transitory machine-readable medium of claim 21 , wherein a subset of FPFs in the plurality of FPFs corresponds to a computing service offered by the SoC, wherein the subset of FPFs has a cardinality of operational fuses, and wherein the cardinality has a parity.

23. The at least one non-transitory machine-readable medium of claim 22 , further comprising instructions which, when executed by the machine, cause the machine to:

provide, by the SoC, the computing service only if the parity of the cardinality of the FPF subset is odd.