Flexible microcontroller support for device testing and manufacturing

Patent metadata

Field	Value
Publication number	US-2020183804-A1
Application number	US-201816213004-A
Country	US
Kind code	A1
Filing date	Dec 7, 2018
Priority date	Dec 7, 2018
Publication date	Jun 11, 2020
Grant date	—

Abstract

The disclosed technology is generally directed to microcontrollers. In one example of the technology, an operating system is run on at least one processor of a multi-core controller. At the operating system, a command that is associated with a manufacturer test mode is received. A permission associated with the command is requested. The permission is based, at least in part, on the status of a one-way e-fuse. Responsive to the permission associated with the command being granted, the command is caused to be processed.

First claim

We claim:

1 . An apparatus, comprising:
a device including at least one memory adapted to store run-time data for the device, and at least one processor that is adapted to execute processor-executable code that, in response to execution, enables the device to perform actions, including:
running an operating system on at least one processor of a multi-core controller;
receiving, at the operating system, a command that is associated with a manufacturer test mode;
requesting a permission associated with the command, wherein the permission is based, at least in part, on the status of a one-way e-fuse; and
responsive to the permission associated with the command being granted, causing the command to be processed.

2 . The apparatus of claim 1 , the actions further including:
responsive to the manufacturer test mode being done, causing the one-way e-fuse to be blown.

3 . The apparatus of claim 1 , wherein
if the one-way e-fuse is not blown or a valid manufacturer test mode certificate associated uniquely with the device is presented
the permission associated with the command is granted;
else
the permission is denied.

4 . The apparatus of claim 1 , wherein the device includes a plurality of integrated circuits, the multi-core microcontroller is included on a first integrated circuit of the plurality of integrated circuits, and wherein requesting the permission associated with the command includes:
communicating a manufacturer test mode query from the operating system to a security subsystem, wherein the security subsystem is on a second integrated circuit of the plurality of integrated circuits, and wherein the second integrated circuit of the plurality of integrated circuits is different from the first integrated circuit of the plurality of integrated circuits; and communicating a response to the manufacturer test mode query from the security subsystem to the operating system, wherein the response to the manufacturer test mode query indicates whether permission for the manufacturer test mode is granted.

5 . The apparatus of claim 1 , wherein the device further includes a radio, and wherein the manufacturer test mode enables the radio to operate out of compliance.

6 . The apparatus of claim 1 , wherein
responsive to the permission associated with the command being granted, the manufacturer test mode is generally enabled.

7 . The apparatus of claim 1 , wherein
responsive to the permission associated with the command being granted, the manufacturer test mode is enabled for the command.

8 . The apparatus of claim 1 , the actions further including:
performing a self-check, wherein the self-check includes determining whether the e-fuse has been blown; and externally reporting results of the self-check.

9 . The apparatus of claim 1 , the actions further including:
receiving a remote command to blow the e-fuse; and in response to the remote command, causing the e-fuse to be blown.

10 . The apparatus of claim 1 , the actions further including:
enforcing reduced functionality for the device while the e-fuse has not been blown.

11 . The apparatus of claim 1 , wherein the actions further include:
installing a relay on the at least one processor, wherein the relay communicates the command from a testing host to the operating system.

12 . The apparatus of claim 11 , the actions further including:
responsive to the manufacturer test mode being done:
causing the e-fuse to be blown; and
uninstalling the relay.

13 . A method, comprising:
running an operating system on at least one processor of a multi-core controller; receiving, at the operating system, a request to enter a manufacturer test mode; querying a security subsystem for permission to enter the manufacturer test mode; receiving a response to the query from the security subsystem; and responsive to the response to the query from the security subsystem indicating that permission to enter the manufacturer test mode is granted, entering the manufacturer test mode.

14 . The method of claim 13 , further comprising:
installing a relay on the at least one processor, wherein the relay communicates the command from a testing host to the operating system.

15 . The method of claim 13 , wherein
the security subsystem is configured to monitor a one-way e-fuse; and if the one-way e-fuse is not blown or a valid manufacturer test mode certificate associated uniquely with the device is presented
the permission associated with the command is granted by the security subsystem;
else
the permission is denied by the security subsystem.

16 . The method of claim 15 , further comprising:
responsive to the manufacturer test mode being done, causing the one-way e-fuse to be blown.

17 . A processor-readable storage medium, having stored thereon process-executable code for computer network design, that, responsive to execution by at least one processor, enables actions, comprising:
receiving, at an operating system, a command that is associated with a manufacturer test mode; evaluating permission associated with the command, wherein the permission is based, at least in part, on the status of a one-way e-fuse; and causing the command to be processed responsive to the permission associated with the command being granted.

18 . The processor-readable storage medium of claim 17 , the actions further comprising:
responsive to the manufacturer test mode being done, causing the one-way e-fuse to be blown.

19 . The processor-readable storage medium of claim 17 , wherein
if the one-way e-fuse is not blown or a valid manufacturer test mode certificate associated uniquely with the device is presented
the permission associated with the command is granted;
else
the permission is denied.

20 . The processor-readable storage medium of claim 17 , wherein operating system is running on a processor of a first integrated circuit of a plurality of integrated circuits on a device, and wherein evaluating the permission associated with the command includes:
causing communication of a manufacturer test mode query from the operating system to a security subsystem, wherein the security subsystem is on a second integrated circuit of the plurality of integrated circuits, and wherein the second integrated circuit of the plurality of integrated circuits is different from the first integrated circuit of the plurality of integrated circuits; receiving, by the operating system, a response to the manufacturer test mode query from the security subsystem to the operating system, wherein the response to the manufacturer test mode query indicates whether permission for the manufacturer test mode is granted; and determining, by the operating system, after the response to the manufacturer test mode query is received, whether the response to the manufacturer test mode query indicates that permission for the manufacturer test mode is granted.

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Chen Nicholas Yen-Cherng
• Hodges Stephen E

Classifications

• G06F11/26

  Functional testing · CPC title

• G06F21/79

  in semiconductor storage media, e.g. directly-addressable memories · CPC title

• G06F21/74 Primary

  operating in dual or compartmented mode, i.e. at least one secure mode · CPC title

• G06F21/629

  to features or functions of an application · CPC title

• G06F11/27 Primary

  Built-in tests · CPC title