Device Security
281
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
System Controller (SYSCTL)
NOTE:
The command for factory reset boot override through JTAG is lost on a device power cycle.
So care should be taken to ensure that power cycle does not happen during this operation.
In the event of a power cycle, the factory reset command through JTAG should be re-
initiated.
4.8.6.2
Boot Override Through Flash Mailbox
Boot overrides through flash mailbox are used for the following functionality in MSP432P4xx devices:
•
JTAG and SWD lock enable: To enable the JTAG and SWD lock for the device.
•
IP protection enable: To enable the IP protection definition for any combination of the four different
secure zones needed by the application.
•
Factory Reset: To erase the entire flash main memory. Remove all security definitions in the system.
•
Factory Reset configuration: To enable password for factory reset or to disable factory reset
functionality.
•
BSL configuration: To enable or disable the device BSL and to set up various BSL parameters
•
In-field update: Encrypted update for JTAG and SWD locked or encrypted or unencrypted update to
any of the IP protected secure zone in the device
The security settings of the MSP432P4xx devices can be configured by the boot-code on the basis of a
flash based mail box, FL_BOOTOVER_MAILBOX. The flash mailbox is located in the information memory
of flash. See the device datasheet for the actual address of the flash mailbox. The flash mailbox defines a
series of commands and parameters which have to be setup by the user. The flash mailbox can be
programmed with the appropriate values like any other flash location. When the setup of the flash mailbox
is complete, the application must initiate a REBOOT using the SYS_RESET_REQ register. The boot-code
now finds a boot-override request command in the flash mailbox and proceeds to execute the required
command.
4.8.6.2.1
Boot Override Flash Mailbox (FL_BOOTOVER_MAILBOX)
The structure of the mailbox is given below. Only relative addresses have been provided for the flash
mailbox. Absolute addresses may be device dependent, and this data is available on the device-specific
data sheet.
Table 4-1. Boot Override Flash Mailbox
Mailbox
Offset
Group
Description
Value
0x0
MB_START
Mail box start (must be programed by the user for the boot
code to determine a valid flash boot override mailbox)
0x0115ACF6
0x4
GEN_PARAMS
CMD
Command for boot override operations. To be programed by
user when setting up the flash mailbox.
0x8
Reserved
Reserved
0xFFFFFFFF
0xC
Reserved
0xFFFFFFFF
0x10
JTAG_SWD_LOCK_PARAMS
JTAG_SWD_LOCK_SECEN
JTAG and SWD lock enable
Disable = 0xFFFFFFFF (default state)
Enable = 0x00000000 (any value other than 0xFFFFFFFF)
0x14-0x20
JTAG_SWD_LOCK_AES_INIT_VECT[0-3]
JTAG and SWD lock AES initialization vector for AES-CBC to
be used for enrypted updates
0x24-0x40
JTAG_SWD_LOCK_AES_SECKEYS[0-7]
JTAG and SWD lock AES CBC security keys 0–7. This is the
key that is used to generate the ENCPAYLOAD when the user
intends to do an upgrade.
0xFFFFFFFF when security is disabled.
0x44-0x50
JTAG_SWD_LOCK_UNENC_PWD[0-3]
JTAG and SWD lock unencrypted password
0xFFFFFFFF when security is disabled.
0x54
ACK
Acknowledgment for this command
0x58-0x5C
Reserved
Reserved