soc: silabs: s2: Only configure SMU and SAU once on boot

If a bootloader is used, it will configure the SMU and SAU.
The application cannot also configure it, since it can't know
what alias (S vs NS) to access the CMU through. Only connect
the interrupt to the application's vector table if a bootloader
is present.

Signed-off-by: Aksel Skauge Mellbye <aksel.mellbye@silabs.com>

Author: asmellby

soc/silabs/silabs_s2/soc.c

@@ -81,8 +81,11 @@ void soc_prep_hook(void)
 	 * all bus transactions from the CPU have non-secure attribution.
 	 * This makes the secure-only app behave more like a non-secure app, allowing the use of
 	 * libraries that only expect to use non-secure peripherals, such as the radio subsystem.
+	 * If MCUboot is used, assume that the bootloader has configured the SMU and SAU
+	 * appropriately, and only connect the IRQ for SMU faults.
 	 */
 #if defined(CONFIG_ARM_SECURE_FIRMWARE) && !defined(CONFIG_ARM_FIRMWARE_HAS_SECURE_ENTRY_FUNCS)
+#if !defined(CONFIG_BOOTLOADER_MCUBOOT)
 #if defined(CMU_CLKEN1_SMU)
 	CMU_S->CLKEN1_SET = CMU_CLKEN1_SMU;
 #endif
@@ -100,6 +103,7 @@ void soc_prep_hook(void)
 	NVIC_ClearPendingIRQ(SMU_SECURE_IRQn);
 	SMU->IF_CLR = SMU_IF_PPUSEC | SMU_IF_BMPUSEC;
 	SMU->IEN = SMU_IEN_PPUSEC | SMU_IEN_BMPUSEC;
+#endif
 
 	IRQ_DIRECT_CONNECT(SMU_SECURE_IRQn, 0, smu_fault, 0);
 	irq_enable(SMU_SECURE_IRQn);