The AM261x LaunchPad features a High Security, Field Securable (HS-FS) device. An HS-FS device has the ability to use a one time programming to convert the device from HS-FS to High Security, Security Enforced (HS-SE) device.

The AM261x device leaves the TI factory in an HS-FS state where customer keys are not programmed and has the following attributes:

• Does not enforce the secure boot process
• M4 JTAG port is closed
• R5 JTAG port is open
• Security Subsystem firewalls are closed
• SoC Firewalls are open
• ROM Boot expects a TI signed binary (encryption is optional)
• TIFS-MCU binary is signed by the TI private key

The One Time Programmable (OTP) keywriter converts the secure device from HS-FS to HS-SE. The OTP keywriter programs customer keys into the device efuses to enforce secure boot and establish a root of trust. The secure boot requires an image to be encrypted (optional) and signed using customer keys, which will be verified by the SoC. A secure device in the HS-SE state has the following attributes:

• M4, R5 JTAG ports are both closed
• Security Subsystems and SoC Firewalls are both closed
• TIFS-MCU and SBL need to be signed with active customer key