hw/hppa/machine: Disable default devices with --nodefaults option

Recognize the qemu --nodefaults option, which will disable the
following default devices on hppa:
- lsi53c895a SCSI controller,
- artist graphics card,
- LASI 82596 NIC,
- tulip PCI NIC,
- second serial PCI card,
- USB OHCI controller.

Adding this option is very useful to allow manual testing and
debugging of the other possible devices on the command line.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

hw/hppa/machine.c

@@ -346,8 +346,10 @@ static void machine_HP_common_init_tail(MachineState *machine, PCIBus *pci_bus,
     SysBusDevice *s;
 
     /* SCSI disk setup. */
-    dev = DEVICE(pci_create_simple(pci_bus, -1, "lsi53c895a"));
-    lsi53c8xx_handle_legacy_cmdline(dev);
+    if (drive_get_max_bus(IF_SCSI) >= 0) {
+        dev = DEVICE(pci_create_simple(pci_bus, -1, "lsi53c895a"));
+        lsi53c8xx_handle_legacy_cmdline(dev);
+    }
 
     /* Graphics setup. */
     if (machine->enable_graphics && vga_interface_type != VGA_NONE) {
@@ -360,7 +362,7 @@ static void machine_HP_common_init_tail(MachineState *machine, PCIBus *pci_bus,
     }
 
     /* Network setup. */
-    if (enable_lasi_lan()) {
+    if (nd_table[0].used && enable_lasi_lan()) {
         lasi_82596_init(addr_space, translate(NULL, LASI_LAN_HPA),
                         qdev_get_gpio_in(lasi_dev, LASI_IRQ_LAN_HPA));
     }
@@ -385,7 +387,7 @@ static void machine_HP_common_init_tail(MachineState *machine, PCIBus *pci_bus,
     pci_set_word(&pci_dev->config[PCI_SUBSYSTEM_ID], 0x1227); /* Powerbar */
 
     /* create a second serial PCI card when running Astro */
-    if (!lasi_dev) {
+    if (serial_hd(1) && !lasi_dev) {
         pci_dev = pci_new(-1, "pci-serial-4x");
         qdev_prop_set_chr(DEVICE(pci_dev), "chardev1", serial_hd(1));
         qdev_prop_set_chr(DEVICE(pci_dev), "chardev2", serial_hd(2));