arch: arm: mpu: declare and define nxp_mpu_config as const

Declare and define nxp_mpu_config and nxp_mpu_regions
structs as const, as they are not modified in run-time.

Fixes #10320

Signed-off-by: Ioannis Glaropoulos <[email protected]>

Author: ioannisg

include/arch/arm/cortex_m/mpu/nxp_mpu.h

@@ -146,7 +146,7 @@ struct nxp_mpu_config {
 	/* Number of regions */
 	u32_t num_regions;
 	/* Regions */
-	struct nxp_mpu_region *mpu_regions;
+	const struct nxp_mpu_region *mpu_regions;
 	/* SRAM Region */
 	u32_t sram_region;
 };
@@ -159,6 +159,6 @@ struct nxp_mpu_config {
  * for Thread Stack, Stack Guards, etc.) are programmed during runtime, thus,
  * not kept here.
  */
-extern struct nxp_mpu_config mpu_config;
+extern const struct nxp_mpu_config mpu_config;
 
 #endif /* ZEPHYR_INCLUDE_ARCH_ARM_CORTEX_M_MPU_NXP_MPU_H_ */

soc/arm/nxp_kinetis/k6x/nxp_mpu_regions.c

@@ -6,7 +6,7 @@
 #include <soc.h>
 #include <arch/arm/cortex_m/mpu/nxp_mpu.h>
 
-static struct nxp_mpu_region mpu_regions[] = {
+static const struct nxp_mpu_region mpu_regions[] = {
 	/* Region 0 */
 	MPU_REGION_ENTRY("DEBUGGER_0",
 			 0,
@@ -48,7 +48,7 @@ static struct nxp_mpu_region mpu_regions[] = {
 			 REGION_RAM_ATTR),
 };
 
-struct nxp_mpu_config mpu_config = {
+const struct nxp_mpu_config mpu_config = {
 	.num_regions = ARRAY_SIZE(mpu_regions),
 	.mpu_regions = mpu_regions,
 	.sram_region = 4,