hw/m68k/q800: move PROM and checksum calculation from dp8393x device to board

This is in preparation for each board to have its own separate bit storage
format and checksum for storing the MAC address.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@linux-m68k.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210625065401.30170-5-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

hw/m68k/q800.c

@@ -70,6 +70,8 @@
 #define NUBUS_SUPER_SLOT_BASE 0x60000000
 #define NUBUS_SLOT_BASE       0xf0000000
 
+#define SONIC_PROM_SIZE       0x1000
+
 /*
  * the video base, whereas it a Nubus address,
  * is needed by the kernel to have early display and
@@ -211,8 +213,10 @@ static void q800_init(MachineState *machine)
     int32_t initrd_size;
     MemoryRegion *rom;
     MemoryRegion *io;
+    MemoryRegion *dp8393x_prom = g_new(MemoryRegion, 1);
+    uint8_t *prom;
     const int io_slice_nb = (IO_SIZE / IO_SLICE) - 1;
-    int i;
+    int i, checksum;
     ram_addr_t ram_size = machine->ram_size;
     const char *kernel_filename = machine->kernel_filename;
     const char *initrd_filename = machine->initrd_filename;
@@ -319,9 +323,25 @@ static void q800_init(MachineState *machine)
     sysbus = SYS_BUS_DEVICE(dev);
     sysbus_realize_and_unref(sysbus, &error_fatal);
     sysbus_mmio_map(sysbus, 0, SONIC_BASE);
-    sysbus_mmio_map(sysbus, 1, SONIC_PROM_BASE);
     sysbus_connect_irq(sysbus, 0, qdev_get_gpio_in(glue, 2));
 
+    memory_region_init_rom(dp8393x_prom, NULL, "dp8393x-q800.prom",
+                           SONIC_PROM_SIZE, &error_fatal);
+    memory_region_add_subregion(get_system_memory(), SONIC_PROM_BASE,
+                                dp8393x_prom);
+
+    /* Add MAC address with valid checksum to PROM */
+    prom = memory_region_get_ram_ptr(dp8393x_prom);
+    checksum = 0;
+    for (i = 0; i < 6; i++) {
+        prom[i] = nd_table[0].macaddr.a[i];
+        checksum += prom[i];
+        if (checksum > 0xff) {
+            checksum = (checksum + 1) & 0xff;
+        }
+    }
+    prom[7] = 0xff - checksum;
+
     /* SCC */
 
     dev = qdev_new(TYPE_ESCC);