use a const pointer (#732)

retroachievements/retroachievements.c

@@ -13,7 +13,7 @@ void store_retroachievements_credentials(const char *username,
                                          const char *token, void *userdata);
 
 rc_client_t *g_client = NULL;
-uint8_t *g_dmem = NULL;
+const uint8_t *g_dmem = NULL;
 size_t g_dmem_size = 0;
 bool g_game_loaded = false;
 bool g_user_logged_in = false;
@@ -149,7 +149,7 @@ void ra_load_game(const uint8_t *rom, size_t rom_size) {
                                          NULL);
 }
 
-void ra_set_dmem(uint8_t *dmem, size_t dmem_size) {
+void ra_set_dmem(const uint8_t *dmem, size_t dmem_size) {
   g_dmem = dmem;
   g_dmem_size = dmem_size;
 }

retroachievements/retroachievements.h

@@ -6,7 +6,7 @@ void ra_init_client(bool hardcore);
 void ra_shutdown_client();
 bool ra_get_hardcore();
 void ra_load_game(const uint8_t *rom, size_t rom_size);
-void ra_set_dmem(uint8_t *dmem, size_t dmem_size);
+void ra_set_dmem(const uint8_t *dmem, size_t dmem_size);
 void ra_do_frame();
 void ra_do_idle();
 void ra_http_callback(const char *content, size_t content_size, int status_code,

src/device/rdram.rs

@@ -152,7 +152,7 @@ pub fn init(device: &mut device::Device) {
     device.rdram.mem =
         unsafe { Vec::from_raw_parts(ptr, device.rdram.size as usize, device.rdram.size as usize) };
 
-    retroachievements::set_dmem(device.rdram.mem.as_mut_ptr(), device.rdram.size as usize);
+    retroachievements::set_dmem(device.rdram.mem.as_ptr(), device.rdram.size as usize);
 
     // hack, skip RDRAM initialization
     device

src/retroachievements.rs

@@ -235,7 +235,7 @@ pub fn load_game(rom: &[u8], rom_size: usize) {
     unsafe { ra_load_game(rom.as_ptr(), rom_size) };
 }
 
-pub fn set_dmem(dmem: *mut u8, dmem_size: usize) {
+pub fn set_dmem(dmem: *const u8, dmem_size: usize) {
     unsafe { ra_set_dmem(dmem, dmem_size) };
 }