rm0455-stm32h7a37b3-and-stm32h7b0-value-line-advanced-armbased-32bit-mcus-stmicroelectronics.pdf 对 Secure-only areas 的描述如下

• Secure-only area size (SEC_AREA_START1/2 and SEC_AREA_END1/2)

These option bytes configure the size of the secure-only areas in FLASH_SCAR_CUR1/2 registers. They can be changed without any restriction by the user secure application or by the ST secure library running on the device. For user nonsecure application, the secure-only area size can be removed by performing a bank erase with protection removal (see Section 4.3.10), or an RDP level 1 to 0 regression when DMES1/2 set to 1 in either FLASH_SCAR_CUR1/2 or FLASH_SCAR_PRG1/2 (otherwise an option byte change error is raised)

ST secure library 或user secure application具体指的是啥，该怎么用呢。

手册后面有张图表，从中可以看出来一个是 RSS，一个指的是安全区内的用户代码。