sys/puf_sram: CPU specific attributes for variables

cpu/cortexm_common/include/cpu_conf_common.h

@@ -68,6 +68,11 @@ extern "C" {
 #endif
 /** @} */
 
+/**
+ * @brief   Attribute for memory sections required by SRAM PUF
+ */
+#define PUF_SRAM_ATTRIBUTES __attribute__((used, section(".puf")))
+
 #ifdef __cplusplus
 }
 #endif

sys/puf_sram/puf_sram.c

@@ -19,13 +19,13 @@
 #include "puf_sram.h"
 
 /* Allocation of the PUF seed variable */
-__attribute__((used,section(".puf"))) uint32_t puf_sram_seed;
+PUF_SRAM_ATTRIBUTES uint32_t puf_sram_seed;
 
 /* Allocation of the PUF seed state */
-__attribute__((used,section(".puf"))) uint32_t puf_sram_state;
+PUF_SRAM_ATTRIBUTES uint32_t puf_sram_state;
 
 /* Allocation of the memory marker */
-__attribute__((used,section(".puf"))) uint32_t puf_sram_marker;
+PUF_SRAM_ATTRIBUTES uint32_t puf_sram_marker;
 
 void puf_sram_init(const uint8_t *ram, size_t len)
 {