lib: GPT: Fix cppcheck warnings

Change-Id: Ia9e99dc59cbf869b804a24ba029f19f7170860b4
Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>

Author: adeaarm

lib/gpt/src/gpt.c

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <assert.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -194,7 +195,7 @@ static inline uint64_t gpt_entry_per_lba_count(void);
 static inline void swap_headers(const struct gpt_header_t *src, struct gpt_header_t *dst);
 static psa_status_t count_used_partitions(const struct gpt_t *table,
                                           uint32_t *num_used);
-static inline void parse_entry(struct gpt_entry_t       *entry,
+static inline void parse_entry(const struct gpt_entry_t *entry,
                                struct partition_entry_t *partition_entry);
 static psa_status_t read_from_flash(uint64_t required_lba);
 static psa_status_t read_entry_from_flash(const struct gpt_t *table,
@@ -226,7 +227,7 @@ static bool gpt_entry_cmp_name(const struct gpt_entry_t *entry, const void *name
 static bool gpt_entry_cmp_type(const struct gpt_entry_t *entry, const void *type);
 static psa_status_t validate_table(struct gpt_t *table, bool is_primary);
 static psa_status_t restore_table(struct gpt_t *restore_from, bool is_primary);
-static psa_status_t sort_partition_array(struct gpt_t *table);
+static psa_status_t sort_partition_array(const struct gpt_t *table);
 
 /* PUBLIC API FUNCTIONS */
 
@@ -1006,7 +1007,7 @@ static inline uint64_t gpt_entry_per_lba_count(void)
 }
 
 /* Copies information from the entry to the user visible structure */
-static inline void parse_entry(struct gpt_entry_t       *entry,
+static inline void parse_entry(const struct gpt_entry_t *entry,
                                struct partition_entry_t *partition_entry)
 {
     partition_entry->start = entry->start;
@@ -1604,7 +1605,7 @@ static int cmp_u64(const void *a, const void *b)
 }
 
 /* bsearch but returns the index rather than the item */
-static int64_t bsearch_index(uint64_t arr[], uint32_t len, uint64_t key)
+static int64_t bsearch_index(const uint64_t arr[], uint32_t len, uint64_t key)
 {
     uint32_t l = 0;
     uint32_t r = len;
@@ -1628,8 +1629,12 @@ static int64_t bsearch_index(uint64_t arr[], uint32_t len, uint64_t key)
 /* Sorts the partition array for the given table by the start LBA for each
  * partition. This makes defragmentation easier.
  */
-static psa_status_t sort_partition_array(struct gpt_t *table)
+static psa_status_t sort_partition_array(const struct gpt_t *table)
 {
+    if (table->num_used_partitions == 0) {
+        assert(table->num_used_partitions > 0);
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
     /* To avoid as much I/O as possible, the LBA's for each entry are sorted in
      * memory and then the entries rearranged on flash after
      */