hw/m68k/next-cube: Mirror BIOS to address 0

The ROM is also available at address 0, so add a proper mirror
for this address.

Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-ID: <20230930132351.30282-2-huth@tuxfamily.org>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>

hw/m68k/next-cube.c

@@ -945,6 +945,7 @@ static void next_cube_init(MachineState *machine)
     M68kCPU *cpu;
     CPUM68KState *env;
     MemoryRegion *rom = g_new(MemoryRegion, 1);
+    MemoryRegion *rom2 = g_new(MemoryRegion, 1);
     MemoryRegion *dmamem = g_new(MemoryRegion, 1);
     MemoryRegion *bmapm1 = g_new(MemoryRegion, 1);
     MemoryRegion *bmapm2 = g_new(MemoryRegion, 1);
@@ -993,9 +994,10 @@ static void next_cube_init(MachineState *machine)
     sysbus_create_simple(TYPE_NEXTKBD, 0x0200e000, NULL);
 
     /* Load ROM here */
-    /* still not sure if the rom should also be mapped at 0x0*/
     memory_region_init_rom(rom, NULL, "next.rom", 0x20000, &error_fatal);
     memory_region_add_subregion(sysmem, 0x01000000, rom);
+    memory_region_init_alias(rom2, NULL, "next.rom2", rom, 0x0, 0x20000);
+    memory_region_add_subregion(sysmem, 0x0, rom2);
     if (load_image_targphys(bios_name, 0x01000000, 0x20000) < 8) {
         if (!qtest_enabled()) {
             error_report("Failed to load firmware '%s'.", bios_name);