diff --git a/default-configs/ppc-softmmu.mak b/default-configs/ppc-softmmu.mak
index f5cd0bd..f380ca4 100644
--- a/default-configs/ppc-softmmu.mak
+++ b/default-configs/ppc-softmmu.mak
@@ -41,6 +41,7 @@
 CONFIG_XILINX=y
 CONFIG_XILINX_ETHLITE=y
 CONFIG_OPENPIC=y
+CONFIG_PREP=y
 CONFIG_E500=y
 CONFIG_OPENPIC_KVM=$(and $(CONFIG_E500),$(CONFIG_KVM))
 # For PReP
diff --git a/default-configs/ppc64-softmmu.mak b/default-configs/ppc64-softmmu.mak
index fb34a9b..fcc0452 100644
--- a/default-configs/ppc64-softmmu.mak
+++ b/default-configs/ppc64-softmmu.mak
@@ -42,6 +42,7 @@
 CONFIG_XILINX_ETHLITE=y
 CONFIG_OPENPIC=y
 CONFIG_PSERIES=y
+CONFIG_PREP=y
 CONFIG_E500=y
 CONFIG_OPENPIC_KVM=$(and $(CONFIG_E500),$(CONFIG_KVM))
 # For pSeries
diff --git a/default-configs/ppcemb-softmmu.mak b/default-configs/ppcemb-softmmu.mak
index 4411203..fdf1e14 100644
--- a/default-configs/ppcemb-softmmu.mak
+++ b/default-configs/ppcemb-softmmu.mak
@@ -10,11 +10,9 @@
 CONFIG_VGA_PCI=y
 CONFIG_SERIAL=y
 CONFIG_I8254=y
-CONFIG_PCKBD=y
 CONFIG_FDC=y
 CONFIG_I8257=y
 CONFIG_OPENPIC=y
-CONFIG_PREP_PCI=y
 CONFIG_MACIO=y
 CONFIG_CUDA=y
 CONFIG_ADB=y
@@ -38,6 +36,3 @@
 CONFIG_OPENPIC=y
 CONFIG_E500=y
 CONFIG_OPENPIC_KVM=$(and $(CONFIG_E500),$(CONFIG_KVM))
-# For PReP
-CONFIG_MC146818RTC=y
-CONFIG_ISA_TESTDEV=y
diff --git a/hw/pci-host/prep.c b/hw/pci-host/prep.c
index 042dc8f..0c948e2 100644
--- a/hw/pci-host/prep.c
+++ b/hw/pci-host/prep.c
@@ -47,7 +47,7 @@
     PCIHostState parent_obj;
 
     MemoryRegion intack;
-    qemu_irq irq[4];
+    qemu_irq irq[PCI_NUM_PINS];
     PCIBus pci_bus;
     RavenPCIState pci_dev;
 } PREPPCIState;
@@ -121,11 +121,11 @@
 
     isa_mem_base = 0xc0000000;
 
-    for (i = 0; i < 4; i++) {
+    for (i = 0; i < PCI_NUM_PINS; i++) {
         sysbus_init_irq(dev, &s->irq[i]);
     }
 
-    pci_bus_irqs(&s->pci_bus, prep_set_irq, prep_map_irq, s->irq, 4);
+    pci_bus_irqs(&s->pci_bus, prep_set_irq, prep_map_irq, s->irq, PCI_NUM_PINS);
 
     memory_region_init_io(&h->conf_mem, OBJECT(h), &pci_host_conf_be_ops, s,
                           "pci-conf-idx", 1);
diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs
index 7a1cd5d..2dd5284 100644
--- a/hw/ppc/Makefile.objs
+++ b/hw/ppc/Makefile.objs
@@ -8,7 +8,7 @@
 obj-y += ppc405_boards.o ppc4xx_devs.o ppc405_uc.o ppc440_bamboo.o
 obj-y += ppc4xx_pci.o
 # PReP
-obj-y += prep.o
+obj-$(CONFIG_PREP) += prep.o
 # OldWorld PowerMac
 obj-y += mac_oldworld.o
 # NewWorld PowerMac
diff --git a/hw/ppc/prep.c b/hw/ppc/prep.c
index aad0f69..9f8538c 100644
--- a/hw/ppc/prep.c
+++ b/hw/ppc/prep.c
@@ -656,7 +656,7 @@
     sysctrl->reset_irq = cpu->env.irq_inputs[PPC6xx_INPUT_HRESET];
 
     portio_list_init(port_list, NULL, prep_portio_list, sysctrl, "prep");
-    portio_list_add(port_list, get_system_io(), 0x0);
+    portio_list_add(port_list, isa_address_space_io(isa), 0x0);
 
     /* PowerPC control and status register group */
 #if 0