SWCU185G January 2018 – June 2024 CC1312PSIP , CC1312R , CC1352P , CC1352R , CC2642R , CC2642R-Q1 , CC2652P , CC2652PSIP , CC2652R , CC2652RB , CC2652RSIP , CC2662R-Q1
The ROM bootloader supports commands that can read the flash image. Due to this read capability, a secure measure for disabling the bootloader has been implemented. If the bootloader is disabled using the CCFG BOOTLOADER_ENABLE parameter, the bootloader is unable to execute any commands, which prevents attackers from using the bootloader if the program counter (PC) of the Arm® Cortex®-M4F processor is forced to execute from the bootloader code.
In TI distributed software, the CCFG parameters are set at compile time in the ccfg.c file. The CCFG BOOTLOADER_ENABLE parameter is configured by the value of the SET_CCFG_BL_CONFIG_BOOTLOADER_ENABLE define, which is found in ccfg.c.
Even if the bootloader is disabled, it can still execute the CMD_GET_STATUS command. This makes it possible to verify that a CMD_DOWNLOAD_CRC command has executed correctly (even if the downloaded flash image contains CCFG data that disables the bootloader). If any command other than CMD_GET_STATUS is sent to the device while the bootloader is disabled, the bootloader will stop responding even to a following CMD_GET_STATUS command.