N64: support fast ROM loading (#862)

Normal ROM loading is still supported to not break older versions of the
core.

menu.cpp

@@ -2422,7 +2422,7 @@ void HandleUI(void)
 				}
 				else if (is_n64())
 				{
-					if (!n64_rom_tx(selPath, idx)) Info("failed to load ROM");
+					if (!n64_rom_tx(selPath, idx, load_addr)) Info("failed to load ROM");
 				}
 				else
 				{

support/n64/n64.cpp

@@ -2,6 +2,7 @@
 #include "n64_cpak_header.h"
 #include "../../menu.h"
 #include "../../user_io.h"
+#include "../../shmem.h"
 
 #include <stdio.h>
 #include <string.h>
@@ -1043,7 +1044,7 @@ static void unmount_all_save_files()
 	mounted_save_files = 0;
 }
 
-int n64_rom_tx(const char *name, unsigned char idx) {
+int n64_rom_tx(const char *name, unsigned char idx, uint32_t load_addr) {
 	static uint8_t buf[4096];
 	fileTYPE f;
 
@@ -1058,7 +1059,7 @@ int n64_rom_tx(const char *name, unsigned char idx) {
 	user_io_set_index(idx);
 
 	// prepare transmission of new file
-	user_io_set_download(1);
+	user_io_set_download(1, load_addr ? data_size : 0);
 
 	const int use_progress = 1;
 	if (use_progress) ProgressMessage(0, 0, 0, 0);
@@ -1107,6 +1108,9 @@ int n64_rom_tx(const char *name, unsigned char idx) {
 	MD5Context ctx;
 	MD5Init(&ctx);
 
+	uint8_t *mem = load_addr ? (uint8_t *)shmem_map(fpga_mem(load_addr), data_size) : nullptr;
+	uint8_t *write_ptr = mem;
+
 	while (data_left) {
 		size_t chunk = (data_left > sizeof(buf)) ? sizeof(buf) : data_left;
 
@@ -1181,13 +1185,25 @@ int n64_rom_tx(const char *name, unsigned char idx) {
 			}
 		}
 
-		user_io_file_tx_data(buf, chunk);
+		// copy to DDR memory for fast ROM loading
+		if (write_ptr)
+		{
+			memcpy(write_ptr, buf, chunk);
+			write_ptr += chunk;
+		}
+		else
+		{
+			user_io_file_tx_data(buf, chunk);
+		}
 
 		if (use_progress) ProgressMessage("Loading", f.name, data_size - data_left, data_size);
 		data_left -= chunk;
 		is_first_chunk = false;
 	}
 
+	if (mem)
+		shmem_unmap(mem, data_size);
+
 	MD5Final(md5, &ctx);
 	md5_to_hex(md5, md5_hex);
 	printf("File MD5: %s\n", md5_hex); 

support/n64/n64.h

@@ -4,7 +4,7 @@
 #include <stdint.h>
 #include "../../file_io.h"
 
-int n64_rom_tx(const char* name, unsigned char index);
+int n64_rom_tx(const char* name, unsigned char index, uint32_t load_addr);
 void n64_load_savedata(uint64_t lba, int ack, uint64_t& buffer_lba, uint8_t* buffer, uint32_t buffer_size, uint32_t blksz, uint32_t sz);
 void n64_save_savedata(uint64_t lba, int ack, uint64_t& buffer_lba, uint8_t* buffer, uint32_t blksz, uint32_t sz);