WIP [nrf noup] boot/zephyr: nRF54h20 resume from S2RAM

boot/zephyr/CMakeLists.txt

@@ -482,6 +482,12 @@ zephyr_library_sources(
 )
 endif()
 
+if(CONFIG_SOC_NRF54H20_PM_S2RAM_OVERRIDE)
+zephyr_library_sources(
+  ${BOOT_DIR}/zephyr/nrf54h20_custom_s2ram.c
+)
+endif()
+
 if(CONFIG_MCUBOOT_BOOT_BANNER)
   # Replace Zephyr's boot banner with the MCUboot one
   zephyr_sources(kernel/banner.c)

boot/zephyr/nrf54h20_custom_s2ram.c

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdbool.h>
+#include <zephyr/arch/common/pm_s2ram.h>
+#include <hal/nrf_resetinfo.h>
+#include "pm_s2ram.h"
+#include "power.h"
+
+#include <zephyr/devicetree.h>
+#include <zephyr/storage/flash_map.h>
+
+int soc_s2ram_suspend(pm_s2ram_system_off_fn_t system_off)
+{
+	(void)(system_off);
+	return -1;
+}
+
+void pm_s2ram_mark_set(void)
+{
+	/* empty */
+}
+
+struct arm_vector_table {
+    uint32_t msp;
+    uint32_t reset;
+};
+
+bool pm_s2ram_mark_check_and_clear(void)
+{
+	uint32_t reset_reason = nrf_resetinfo_resetreas_local_get(NRF_RESETINFO);
+
+	if (reset_reason != NRF_RESETINFO_RESETREAS_LOCAL_UNRETAINED_MASK) {
+		// normal boot
+		return false;
+	}
+
+	// s2ram boot
+    struct arm_vector_table *vt;
+    vt = (struct arm_vector_table *)(FIXED_PARTITION_OFFSET(slot0_partition) + 0x800);
+
+	// Jump to application
+    __asm__ volatile (
+        /* vt->reset -> r0 */
+        "   mov     r0, %0\n"
+        /* vt->msp -> r1 */
+        "   mov     r1, %1\n"
+        /* set stack pointer */
+        "   msr     msp, r1\n"
+        /* jump to reset vector of an app */
+        "   bx      r0\n"
+        :
+        : "r" (vt->reset), "r" (vt->msp)
+        : "r0", "r1", "memory"
+    );
+
+	while(1)
+	{
+	}
+
+	return true;
+}