mips: limit RAM size to 256MB on malta and qemu boards

This avoid crash when a bigger RAM size is requested (the devices are
mapped at 0x01000000).

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6419 c046a42c-6fe2-441c-8c8c-71466251a162

hw/mips_malta.c

@@ -802,6 +802,12 @@ void mips_malta_init (ram_addr_t ram_size, int vga_ram_size,
     qemu_register_reset(main_cpu_reset, env);
 
     /* allocate RAM */
+    if (ram_size > (256 << 20)) {
+        fprintf(stderr,
+                "qemu: Too much memory for this machine: %d MB, maximum 256 MB\n",
+                ((unsigned int)ram_size / (1 << 20)));
+        exit(1);
+    }
     cpu_register_physical_memory(0, ram_size, IO_MEM_RAM);
 
     /* Map the bios at two physical locations, as on the real board. */

hw/mips_r4k.c

@@ -178,6 +178,12 @@ void mips_r4k_init (ram_addr_t ram_size, int vga_ram_size,
     qemu_register_reset(main_cpu_reset, env);
 
     /* allocate RAM */
+    if (ram_size > (256 << 20)) {
+        fprintf(stderr,
+                "qemu: Too much memory for this machine: %d MB, maximum 256 MB\n",
+                ((unsigned int)ram_size / (1 << 20)));
+        exit(1);
+    }
     cpu_register_physical_memory(0, ram_size, IO_MEM_RAM);
 
     if (!mips_qemu_iomemtype) {