vboot_reference: add const to char* params in cgpt

cgpt's C/C++ bindings use non-const char* parameters leading to
compiler errors if a user attempts to pass a const char* parameter
rather than creating an unnecessary mutable copy.

Since the code doesn't need to modify the parameters, change them to
const char* to make the library easier to use.

BUG=none
TEST=builds and test cgpt cli tool on-device.
CQ-DEPEND=CL:1460081
BRANCH=none

Change-Id: I6552db159e3dc4d9d07bb889a3f1e4e890b33cb0
Reviewed-on: https://chromium-review.googlesource.com/1459848
Commit-Ready: Fletcher Woodruff <fletcherw@chromium.org>
Tested-by: Fletcher Woodruff <fletcherw@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

2 files changed, 5 insertions, 5 deletions

diff --git a/cgpt/cgpt_add.c b/cgpt/cgpt_add.c
index c0e93f3d..786f2bc5 100644
--- a/cgpt/cgpt_add.c
+++ b/cgpt/cgpt_add.c
@@ -92,7 +92,7 @@ static int GptSetEntryAttributes(struct drive *drive,
   if (params->set_type)
     memcpy(&entry->type, &params->type_guid, sizeof(Guid));
   if (params->label) {
-    if (CGPT_OK != UTF8ToUTF16((uint8_t *)params->label, entry->name,
+    if (CGPT_OK != UTF8ToUTF16((const uint8_t *)params->label, entry->name,
                                sizeof(entry->name) / sizeof(entry->name[0]))) {
       Error("The label cannot be converted to UTF16.\n");
       return -1;
diff --git a/cgpt/cgpt_find.c b/cgpt/cgpt_find.c
index e207fb3a..bf94b589 100644
--- a/cgpt/cgpt_find.c
+++ b/cgpt/cgpt_find.c
@@ -69,7 +69,7 @@ static int match_content(CgptFindParams *params, struct drive *drive,
 }
 
 // This needs to handle /dev/mmcblk0 -> /dev/mmcblk0p3, /dev/sda -> /dev/sda3
-static void showmatch(CgptFindParams *params, char *filename,
+static void showmatch(CgptFindParams *params, const char *filename,
                       int partnum, GptEntry *entry) {
   char * format = "%s%d\n";
 
@@ -97,7 +97,7 @@ static void showmatch(CgptFindParams *params, char *filename,
 
 // This handles the MTD devices. ChromeOS uses /dev/mtdX for kernel partitions,
 // /dev/ubiblockX_0 for root partitions, and /dev/ubiX for stateful partition.
-static void chromeos_mtd_show(CgptFindParams *params, char *filename,
+static void chromeos_mtd_show(CgptFindParams *params, const char *filename,
                               int partnum, GptEntry *entry) {
   if (GuidEqual(&guid_chromeos_kernel, &entry->type)) {
     printf("/dev/mtd%d\n", partnum);
@@ -113,7 +113,7 @@ static void chromeos_mtd_show(CgptFindParams *params, char *filename,
 // filename and partition number that matched is left in a global, since we
 // could have multiple hits.
 static int gpt_search(CgptFindParams *params, struct drive *drive,
-                      char *filename) {
+                      const char *filename) {
   int i;
   GptEntry *entry;
   int retval = 0;
@@ -155,7 +155,7 @@ static int gpt_search(CgptFindParams *params, struct drive *drive,
   return retval;
 }
 
-static int do_search(CgptFindParams *params, char *fileName) {
+static int do_search(CgptFindParams *params, const char *fileName) {
   int retval;
   struct drive drive;