From 36c772aa6d50a722c9f5e3962aa6679ad1999db9 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 cause 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>
---
 soc/silabs/silabs_s2/Kconfig |  4 +++
 soc/silabs/silabs_s2/soc.c   | 63 ++++++++++++++++++++++++++++++++++++
 west.yml                     |  2 +-
 3 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/soc/silabs/silabs_s2/Kconfig b/soc/silabs/silabs_s2/Kconfig
index 793a34bd6d2e1e..21129590f14f17 100644
--- a/soc/silabs/silabs_s2/Kconfig
+++ b/soc/silabs/silabs_s2/Kconfig
@@ -6,10 +6,14 @@ 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
+
 config HW_HAS_SILABS_DCDC
 	def_bool $(dt_compat_enabled,$(DT_COMPAT_SILABS_SERIES2_DCDC))
 
diff --git a/soc/silabs/silabs_s2/soc.c b/soc/silabs/silabs_s2/soc.c
index a4861878f39ae2..e58823c16f9637 100644
--- a/soc/silabs/silabs_s2/soc.c
+++ b/soc/silabs/silabs_s2/soc.c
@@ -11,6 +11,7 @@
 
 #include <zephyr/kernel.h>
 #include <zephyr/logging/log.h>
+#include <soc.h>
 
 #include <em_chip.h>
 
@@ -22,6 +23,18 @@
 #include <sl_power_manager.h>
 #endif
 
+#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)
@@ -39,3 +52,53 @@ void soc_early_init_hook(void)
 	sl_hfxo_manager_init();
 #endif
 }
+
+#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)
+	CMU_S->CLKEN1_SET = CMU_CLKEN1_SMU;
+
+	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 8108a1b13a541c..399d7ced23a106 100644
--- a/west.yml
+++ b/west.yml
@@ -223,7 +223,7 @@ manifest:
       groups:
         - hal
     - name: hal_silabs
-      revision: pull/73/head
+      revision: pull/74/head
       path: modules/hal/silabs
       groups:
         - hal