diff --git a/boot/zephyr/single_loader.c b/boot/zephyr/single_loader.c
new file mode 100644
index 0000000..258d38b
--- /dev/null
+++ b/boot/zephyr/single_loader.c
@@ -0,0 +1,126 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2020 Nordic Semiconductor ASA
+ */
+
+#include <assert.h>
+#include "bootutil/image.h"
+#include "bootutil_priv.h"
+#include "bootutil/bootutil_log.h"
+
+#include "mcuboot_config/mcuboot_config.h"
+
+MCUBOOT_LOG_MODULE_DECLARE(mcuboot);
+
+/* Variables passed outside of unit via poiters. */
+static const struct flash_area *_fa_p;
+static struct image_header _hdr = { 0 };
+
+#ifdef MCUBOOT_VALIDATE_PRIMARY_SLOT
+/**
+ * Validate hash of a primary boot image.
+ *
+ * @param[in]	fa_p	flash area pointer
+ * @param[in]	hdr	boot image header pointer
+ *
+ * @return		0 on success, error code otherwise
+ */
+inline static int
+boot_image_validate(const struct flash_area *fa_p,
+                    struct image_header *hdr)
+{
+    static uint8_t tmpbuf[BOOT_TMPBUF_SZ];
+
+    /* NOTE: The enc-state pointer may be NULL only because when there is
+     * only one image (BOOT_IMAGE_NUMBER == 1), the code that uses the
+     * pointer, within bootutil_img_validate and down the call path,
+     * is excluded from compilation.
+     */
+    /* Validate hash */
+    if (bootutil_img_validate(NULL, 0, hdr, fa_p, tmpbuf,
+                              BOOT_TMPBUF_SZ, NULL, 0, NULL)) {
+        return BOOT_EBADIMAGE;
+    }
+
+    return 0;
+}
+#endif /* MCUBOOT_VALIDATE_PRIMARY_SLOT */
+
+
+/**
+ * Attempts to load image header from flash; verifies flash header fields.
+ *
+ * @param[in]	fa_p	flash area pointer
+ * @param[out] 	hdr	buffer for image header
+ *
+ * @return		0 on success, error code otherwise
+ */
+static int
+boot_image_load_header(const struct flash_area *fa_p,
+                       struct image_header *hdr)
+{
+    uint32_t size;
+    int rc = flash_area_read(fa_p, 0, hdr, sizeof *hdr);
+
+    if (rc != 0) {
+        rc = BOOT_EFLASH;
+        BOOT_LOG_ERR("Failed reading image header");
+	return BOOT_EFLASH;
+    }
+
+    if (hdr->ih_magic != IMAGE_MAGIC) {
+        BOOT_LOG_ERR("Bad image magic 0x%lx", (unsigned long)hdr->ih_magic);
+
+        return BOOT_EBADIMAGE;
+    }
+
+    if (hdr->ih_flags & IMAGE_F_NON_BOOTABLE) {
+        BOOT_LOG_ERR("Image not bootable");
+
+        return BOOT_EBADIMAGE;
+    }
+
+    if (!boot_u32_safe_add(&size, hdr->ih_img_size, hdr->ih_hdr_size) ||
+        size >= fa_p->fa_size) {
+        return BOOT_EBADIMAGE;
+    }
+
+    return 0;
+}
+
+
+/**
+ * Gather information on image and prepare for booting.
+ *
+ * @parami[out]	rsp	Parameters for booting image, on success
+ *
+ * @return		0 on success, error code otherwise.
+ */
+int
+boot_go(struct boot_rsp *rsp)
+{
+    int rc = -1;
+
+    rc = flash_area_open(FLASH_AREA_IMAGE_PRIMARY(0), &_fa_p);
+    assert(rc == 0);
+
+    rc = boot_image_load_header(_fa_p, &_hdr);
+    if (rc != 0)
+        goto out;
+
+#ifdef MCUBOOT_VALIDATE_PRIMARY_SLOT
+    rc = boot_image_validate(_fa_p, &_hdr);
+    if (rc != 0) {
+        goto out;
+    }
+#endif /* MCUBOOT_VALIDATE_PRIMARY_SLOT */
+
+    rsp->br_flash_dev_id = _fa_p->fa_device_id;
+    rsp->br_image_off = _fa_p->fa_off;
+    rsp->br_hdr = &_hdr;
+
+out:
+    flash_area_close(_fa_p);
+    return rc;
+}