diff --git a/src/boot/efi/util.c b/src/boot/efi/util.c
index fd4be681a5..a7bba3120b 100644
--- a/src/boot/efi/util.c
+++ b/src/boot/efi/util.c
@@ -59,7 +59,7 @@ UINT64 time_usec(VOID) {
         return 1000 * 1000 * ticks / freq;
 }
 
-EFI_STATUS parse_boolean(CHAR8 *v, BOOLEAN *b) {
+EFI_STATUS parse_boolean(const CHAR8 *v, BOOLEAN *b) {
         if (strcmpa(v, (CHAR8 *)"1") == 0 ||
             strcmpa(v, (CHAR8 *)"yes") == 0 ||
             strcmpa(v, (CHAR8 *)"y") == 0 ||
@@ -79,28 +79,28 @@ EFI_STATUS parse_boolean(CHAR8 *v, BOOLEAN *b) {
         return EFI_INVALID_PARAMETER;
 }
 
-EFI_STATUS efivar_set_raw(const EFI_GUID *vendor, CHAR16 *name, VOID *buf, UINTN size, BOOLEAN persistent) {
+EFI_STATUS efivar_set_raw(const EFI_GUID *vendor, const CHAR16 *name, const VOID *buf, UINTN size, BOOLEAN persistent) {
         UINT32 flags;
 
         flags = EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS;
         if (persistent)
                 flags |= EFI_VARIABLE_NON_VOLATILE;
 
-        return uefi_call_wrapper(RT->SetVariable, 5, name, (EFI_GUID *)vendor, flags, size, buf);
+        return uefi_call_wrapper(RT->SetVariable, 5, (CHAR16*) name, (EFI_GUID *)vendor, flags, size, (VOID*) buf);
 }
 
-EFI_STATUS efivar_set(CHAR16 *name, CHAR16 *value, BOOLEAN persistent) {
+EFI_STATUS efivar_set(const CHAR16 *name, const CHAR16 *value, BOOLEAN persistent) {
         return efivar_set_raw(&loader_guid, name, value, value ? (StrLen(value)+1) * sizeof(CHAR16) : 0, persistent);
 }
 
 EFI_STATUS efivar_set_int(CHAR16 *name, UINTN i, BOOLEAN persistent) {
         CHAR16 str[32];
 
-        SPrint(str, 32, L"%d", i);
+        SPrint(str, 32, L"%u", i);
         return efivar_set(name, str, persistent);
 }
 
-EFI_STATUS efivar_get(CHAR16 *name, CHAR16 **value) {
+EFI_STATUS efivar_get(const CHAR16 *name, CHAR16 **value) {
         _cleanup_freepool_ CHAR8 *buf = NULL;
         CHAR16 *val;
         UINTN size;
@@ -118,7 +118,7 @@ EFI_STATUS efivar_get(CHAR16 *name, CHAR16 **value) {
         return EFI_SUCCESS;
 }
 
-EFI_STATUS efivar_get_int(CHAR16 *name, UINTN *i) {
+EFI_STATUS efivar_get_int(const CHAR16 *name, UINTN *i) {
         _cleanup_freepool_ CHAR16 *val = NULL;
         EFI_STATUS err;
 
@@ -129,7 +129,7 @@ EFI_STATUS efivar_get_int(CHAR16 *name, UINTN *i) {
         return err;
 }
 
-EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, CHAR16 *name, CHAR8 **buffer, UINTN *size) {
+EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, const CHAR16 *name, CHAR8 **buffer, UINTN *size) {
         _cleanup_freepool_ CHAR8 *buf = NULL;
         UINTN l;
         EFI_STATUS err;
@@ -139,7 +139,7 @@ EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, CHAR16 *name, CHAR8 **buffer,
         if (!buf)
                 return EFI_OUT_OF_RESOURCES;
 
-        err = uefi_call_wrapper(RT->GetVariable, 5, name, (EFI_GUID *)vendor, NULL, &l, buf);
+        err = uefi_call_wrapper(RT->GetVariable, 5, (CHAR16*) name, (EFI_GUID *)vendor, NULL, &l, buf);
         if (!EFI_ERROR(err)) {
                 *buffer = buf;
                 buf = NULL;
@@ -287,12 +287,12 @@ CHAR8 *strchra(CHAR8 *s, CHAR8 c) {
         return NULL;
 }
 
-EFI_STATUS file_read(EFI_FILE_HANDLE dir, CHAR16 *name, UINTN off, UINTN size, CHAR8 **content, UINTN *content_size) {
+EFI_STATUS file_read(EFI_FILE_HANDLE dir, const CHAR16 *name, UINTN off, UINTN size, CHAR8 **content, UINTN *content_size) {
         EFI_FILE_HANDLE handle;
         _cleanup_freepool_ CHAR8 *buf = NULL;
         EFI_STATUS err;
 
-        err = uefi_call_wrapper(dir->Open, 5, dir, &handle, name, EFI_FILE_MODE_READ, 0ULL);
+        err = uefi_call_wrapper(dir->Open, 5, dir, &handle, (CHAR16*) name, EFI_FILE_MODE_READ, 0ULL);
         if (EFI_ERROR(err))
                 return err;
 
diff --git a/src/boot/efi/util.h b/src/boot/efi/util.h
index 169bd674d3..f7e0e49c06 100644
--- a/src/boot/efi/util.h
+++ b/src/boot/efi/util.h
@@ -11,26 +11,26 @@ static inline const CHAR16 *yes_no(BOOLEAN b) {
         return b ? L"yes" : L"no";
 }
 
-EFI_STATUS parse_boolean(CHAR8 *v, BOOLEAN *b);
+EFI_STATUS parse_boolean(const CHAR8 *v, BOOLEAN *b);
 
 UINT64 ticks_read(void);
 UINT64 ticks_freq(void);
 UINT64 time_usec(void);
 
-EFI_STATUS efivar_set(CHAR16 *name, CHAR16 *value, BOOLEAN persistent);
-EFI_STATUS efivar_set_raw(const EFI_GUID *vendor, CHAR16 *name, VOID *buf, UINTN size, BOOLEAN persistent);
+EFI_STATUS efivar_set(const CHAR16 *name, const CHAR16 *value, BOOLEAN persistent);
+EFI_STATUS efivar_set_raw(const EFI_GUID *vendor, const CHAR16 *name, const VOID *buf, UINTN size, BOOLEAN persistent);
 EFI_STATUS efivar_set_int(CHAR16 *name, UINTN i, BOOLEAN persistent);
 VOID efivar_set_time_usec(CHAR16 *name, UINT64 usec);
 
-EFI_STATUS efivar_get(CHAR16 *name, CHAR16 **value);
-EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, CHAR16 *name, CHAR8 **buffer, UINTN *size);
-EFI_STATUS efivar_get_int(CHAR16 *name, UINTN *i);
+EFI_STATUS efivar_get(const CHAR16 *name, CHAR16 **value);
+EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, const CHAR16 *name, CHAR8 **buffer, UINTN *size);
+EFI_STATUS efivar_get_int(const CHAR16 *name, UINTN *i);
 
 CHAR8 *strchra(CHAR8 *s, CHAR8 c);
 CHAR16 *stra_to_path(CHAR8 *stra);
 CHAR16 *stra_to_str(CHAR8 *stra);
 
-EFI_STATUS file_read(EFI_FILE_HANDLE dir, CHAR16 *name, UINTN off, UINTN size, CHAR8 **content, UINTN *content_size);
+EFI_STATUS file_read(EFI_FILE_HANDLE dir, const CHAR16 *name, UINTN off, UINTN size, CHAR8 **content, UINTN *content_size);
 
 static inline void FreePoolp(void *p) {
         void *q = *(void**) p;