From d12de2d6b446b04e7e76fd0c644f95eeab4201e7 Mon Sep 17 00:00:00 2001
From: Aksel Skauge Mellbye <aksel.mellbye@silabs.com>
Date: Thu, 3 Oct 2024 21:38:18 +0200
Subject: [PATCH] soc: silabs: Add soc_prep_hook() for Series 2

CMSIS SystemInit is not used in Zephyr. Implement the functionality
that isn't already done by Zephyr startup using soc_prep_hook().

The reason the lack of TrustZone init did not create immediately obvious
issues previously is that SMU faults can only happen if the SMU clock is
enabled.

Signed-off-by: Aksel Skauge Mellbye <aksel.mellbye@silabs.com>
---
 .../hal_silabs/simplicity_sdk/CMakeLists.txt  |  4 --
 soc/silabs/silabs_s2/Kconfig                  |  4 ++
 soc/silabs/silabs_s2/efr32mg21/Kconfig        |  1 +
 soc/silabs/silabs_s2/soc.c                    | 63 +++++++++++++++++++
 west.yml                                      |  2 +-
 5 files changed, 69 insertions(+), 5 deletions(-)

diff --git a/modules/hal_silabs/simplicity_sdk/CMakeLists.txt b/modules/hal_silabs/simplicity_sdk/CMakeLists.txt
index e270d75ad17..949bf579447 100644
--- a/modules/hal_silabs/simplicity_sdk/CMakeLists.txt
+++ b/modules/hal_silabs/simplicity_sdk/CMakeLists.txt
@@ -119,10 +119,6 @@ zephyr_compile_definitions_ifdef(CONFIG_SOC_GECKO_DEV_INIT
   SL_CATALOG_HFXO_MANAGER_PRESENT
 )
 
-zephyr_compile_options(
-  -mcmse # Cortex-M Security Extensions are needed for startup code
-)
-
 zephyr_library_sources(
   ${DEVICE_DIR}/SiliconLabs/${SILABS_DEVICE_FAMILY}/Source/system_${CONFIG_SOC_SERIES}.c
   ${EMLIB_DIR}/src/em_system.c
diff --git a/soc/silabs/silabs_s2/Kconfig b/soc/silabs/silabs_s2/Kconfig
index f105aaf5f49..f25bec21491 100644
--- a/soc/silabs/silabs_s2/Kconfig
+++ b/soc/silabs/silabs_s2/Kconfig
@@ -6,8 +6,12 @@ if SOC_FAMILY_SILABS_S2
 config SOC_FAMILY_SILABS_S2
 	select HAS_SEGGER_RTT if ZEPHYR_SEGGER_MODULE
 	select BUILD_OUTPUT_HEX
+	select SOC_PREP_HOOK
 	select SOC_EARLY_INIT_HOOK
 
 rsource "*/Kconfig"
 
+config ARM_SECURE_FIRMWARE
+	default y
+
 endif
diff --git a/soc/silabs/silabs_s2/efr32mg21/Kconfig b/soc/silabs/silabs_s2/efr32mg21/Kconfig
index 0e34a386b14..db3f7e6ae66 100644
--- a/soc/silabs/silabs_s2/efr32mg21/Kconfig
+++ b/soc/silabs/silabs_s2/efr32mg21/Kconfig
@@ -6,6 +6,7 @@ config SOC_SERIES_EFR32MG21
 	select CPU_CORTEX_M33
 	select CPU_CORTEX_M_HAS_DWT
 	select ARMV8_M_DSP
+	select ARM_TRUSTZONE_M
 	select CPU_HAS_FPU
 	select CPU_HAS_ARM_MPU
 	select CPU_HAS_ARM_SAU
diff --git a/soc/silabs/silabs_s2/soc.c b/soc/silabs/silabs_s2/soc.c
index 7d503aa27ad..a6ad018bc43 100644
--- a/soc/silabs/silabs_s2/soc.c
+++ b/soc/silabs/silabs_s2/soc.c
@@ -18,6 +18,18 @@
 #include <sl_hfxo_manager.h>
 #include <sl_power_manager.h>
 
+#if defined(CONFIG_PRINTK) || defined(CONFIG_LOG)
+#define PR_EXC(...) LOG_ERR(__VA_ARGS__)
+#else
+#define PR_EXC(...)
+#endif /* CONFIG_PRINTK || CONFIG_LOG */
+
+#if (CONFIG_FAULT_DUMP == 2)
+#define PR_FAULT_INFO(...) PR_EXC(__VA_ARGS__)
+#else
+#define PR_FAULT_INFO(...)
+#endif
+
 LOG_MODULE_REGISTER(soc, CONFIG_SOC_LOG_LEVEL);
 
 void soc_early_init_hook(void)
@@ -35,3 +47,54 @@ void soc_early_init_hook(void)
 		sl_hfxo_manager_init();
 	}
 }
+
+#if defined(CONFIG_ARM_SECURE_FIRMWARE) && !defined(CONFIG_ARM_FIRMWARE_HAS_SECURE_ENTRY_FUNCS)
+static void smu_fault(void)
+{
+	PR_FAULT_INFO("***** SMU FAULT *****");
+
+	if (SMU->IF & SMU_IF_BMPUSEC) {
+		PR_FAULT_INFO("Bus Manager Fault");
+		PR_EXC("SMU.BMPUFS=%d", SMU->BMPUFS);
+	}
+	if (SMU->IF & SMU_IF_PPUSEC) {
+		PR_FAULT_INFO("Peripheral Access Fault");
+		PR_EXC("SMU.PPUFS=%d", SMU->PPUFS);
+	}
+
+	z_fatal_error(K_ERR_CPU_EXCEPTION, NULL);
+}
+#endif
+
+void soc_prep_hook(void)
+{
+	/* Initialize TrustZone state of the device.
+	 * If this is a secure app with no non-secure callable functions, it is a secure-only app.
+	 * Configure all peripherals except the SMU and SEMAILBOX to non-secure aliases, and make
+	 * 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 defined(CONFIG_ARM_SECURE_FIRMWARE) && !defined(CONFIG_ARM_FIRMWARE_HAS_SECURE_ENTRY_FUNCS)
+#if defined(CMU_CLKEN1_SMU)
+	CMU_S->CLKEN1_SET = CMU_CLKEN1_SMU;
+#endif
+	SMU->PPUSATD0_CLR = _SMU_PPUSATD0_MASK;
+#if defined(SEMAILBOX_PRESENT)
+	SMU->PPUSATD1_CLR = (_SMU_PPUSATD1_MASK & (~SMU_PPUSATD1_SMU & ~SMU_PPUSATD1_SEMAILBOX));
+#else
+	SMU->PPUSATD1_CLR = (_SMU_PPUSATD1_MASK & ~SMU_PPUSATD1_SMU);
+#endif
+
+	SAU->CTRL = SAU_CTRL_ALLNS_Msk;
+	__DSB();
+	__ISB();
+
+	NVIC_ClearPendingIRQ(SMU_SECURE_IRQn);
+	SMU->IF_CLR = SMU_IF_PPUSEC | SMU_IF_BMPUSEC;
+	SMU->IEN = SMU_IEN_PPUSEC | SMU_IEN_BMPUSEC;
+
+	IRQ_DIRECT_CONNECT(SMU_SECURE_IRQn, 0, smu_fault, 0);
+	irq_enable(SMU_SECURE_IRQn);
+#endif
+}
diff --git a/west.yml b/west.yml
index e4abd856235..557cea2ff26 100644
--- a/west.yml
+++ b/west.yml
@@ -223,7 +223,7 @@ manifest:
       groups:
         - hal
     - name: hal_silabs
-      revision: 5c7a7834a6df7882518a2da127f950d80987dfcb
+      revision: 69a5fad41aced94dc59d3103edd6ef370851e623
       path: modules/hal/silabs
       groups:
         - hal