diff --git a/hw/ppc/ppc405.h b/hw/ppc/ppc405.h
index 82bf8dae93..d63c2acdc7 100644
--- a/hw/ppc/ppc405.h
+++ b/hw/ppc/ppc405.h
@@ -63,6 +63,17 @@ struct ppc4xx_bd_info_t {
     uint32_t bi_iic_fast[2];
 };
 
+/* OPB arbitrer */
+#define TYPE_PPC405_OPBA "ppc405-opba"
+OBJECT_DECLARE_SIMPLE_TYPE(Ppc405OpbaState, PPC405_OPBA);
+struct Ppc405OpbaState {
+    SysBusDevice parent_obj;
+
+    MemoryRegion io;
+    uint8_t cr;
+    uint8_t pr;
+};
+
 /* Peripheral controller */
 #define TYPE_PPC405_EBC "ppc405-ebc"
 OBJECT_DECLARE_SIMPLE_TYPE(Ppc405EbcState, PPC405_EBC);
@@ -208,6 +219,7 @@ struct Ppc405SoCState {
     Ppc405GpioState gpio;
     Ppc405DmaState dma;
     Ppc405EbcState ebc;
+    Ppc405OpbaState opba;
 };
 
 /* PowerPC 405 core */
diff --git a/hw/ppc/ppc405_uc.c b/hw/ppc/ppc405_uc.c
index ff81fb3e20..2c482bc25c 100644
--- a/hw/ppc/ppc405_uc.c
+++ b/hw/ppc/ppc405_uc.c
@@ -310,16 +310,9 @@ static void ppc4xx_pob_init(CPUPPCState *env)
 
 /*****************************************************************************/
 /* OPB arbitrer */
-typedef struct ppc4xx_opba_t ppc4xx_opba_t;
-struct ppc4xx_opba_t {
-    MemoryRegion io;
-    uint8_t cr;
-    uint8_t pr;
-};
-
 static uint64_t opba_readb(void *opaque, hwaddr addr, unsigned size)
 {
-    ppc4xx_opba_t *opba = opaque;
+    Ppc405OpbaState *opba = opaque;
     uint32_t ret;
 
     switch (addr) {
@@ -341,7 +334,7 @@ static uint64_t opba_readb(void *opaque, hwaddr addr, unsigned size)
 static void opba_writeb(void *opaque, hwaddr addr, uint64_t value,
                         unsigned size)
 {
-    ppc4xx_opba_t *opba = opaque;
+    Ppc405OpbaState *opba = opaque;
 
     trace_opba_writeb(addr, value);
 
@@ -366,25 +359,30 @@ static const MemoryRegionOps opba_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
 };
 
-static void ppc4xx_opba_reset (void *opaque)
+static void ppc405_opba_reset(DeviceState *dev)
 {
-    ppc4xx_opba_t *opba;
+    Ppc405OpbaState *opba = PPC405_OPBA(dev);
 
-    opba = opaque;
     opba->cr = 0x00; /* No dynamic priorities - park disabled */
     opba->pr = 0x11;
 }
 
-static void ppc4xx_opba_init(hwaddr base)
+static void ppc405_opba_realize(DeviceState *dev, Error **errp)
 {
-    ppc4xx_opba_t *opba;
+    Ppc405OpbaState *s = PPC405_OPBA(dev);
 
-    trace_opba_init(base);
+    memory_region_init_io(&s->io, OBJECT(s), &opba_ops, s, "opba", 2);
+    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->io);
+}
 
-    opba = g_new0(ppc4xx_opba_t, 1);
-    memory_region_init_io(&opba->io, NULL, &opba_ops, opba, "opba", 0x002);
-    memory_region_add_subregion(get_system_memory(), base, &opba->io);
-    qemu_register_reset(ppc4xx_opba_reset, opba);
+static void ppc405_opba_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->realize = ppc405_opba_realize;
+    dc->reset = ppc405_opba_reset;
+    /* Reason: only works as function of a ppc4xx SoC */
+    dc->user_creatable = false;
 }
 
 /*****************************************************************************/
@@ -1373,6 +1371,8 @@ static void ppc405_soc_instance_init(Object *obj)
     object_initialize_child(obj, "dma", &s->dma, TYPE_PPC405_DMA);
 
     object_initialize_child(obj, "ebc", &s->ebc, TYPE_PPC405_EBC);
+
+    object_initialize_child(obj, "opba", &s->opba, TYPE_PPC405_OPBA);
 }
 
 static void ppc405_reset(void *opaque)
@@ -1410,7 +1410,11 @@ static void ppc405_soc_realize(DeviceState *dev, Error **errp)
     ppc4xx_pob_init(env);
 
     /* OBP arbitrer */
-    ppc4xx_opba_init(0xef600600);
+    sbd = SYS_BUS_DEVICE(&s->opba);
+    if (!sysbus_realize(sbd, errp)) {
+        return;
+    }
+    sysbus_mmio_map(sbd, 0, 0xef600600);
 
     /* Universal interrupt controller */
     s->uic = qdev_new(TYPE_PPC_UIC);
@@ -1523,6 +1527,11 @@ static void ppc405_soc_class_init(ObjectClass *oc, void *data)
 
 static const TypeInfo ppc405_types[] = {
     {
+        .name           = TYPE_PPC405_OPBA,
+        .parent         = TYPE_SYS_BUS_DEVICE,
+        .instance_size  = sizeof(Ppc405OpbaState),
+        .class_init     = ppc405_opba_class_init,
+    }, {
         .name           = TYPE_PPC405_EBC,
         .parent         = TYPE_PPC4xx_DCR_DEVICE,
         .instance_size  = sizeof(Ppc405EbcState),
diff --git a/hw/ppc/trace-events b/hw/ppc/trace-events
index 69a95f9f57..a07d5aca0f 100644
--- a/hw/ppc/trace-events
+++ b/hw/ppc/trace-events
@@ -161,7 +161,6 @@ ppc440_pcix_reg_write(uint64_t addr, uint32_t val, uint32_t size) "addr 0x%" PRI
 # ppc405_boards.c
 opba_readb(uint64_t addr, uint32_t val) "addr 0x%" PRIx64 " = 0x%" PRIx32
 opba_writeb(uint64_t addr, uint64_t val) "addr 0x%" PRIx64 " = 0x%" PRIx64
-opba_init(uint64_t addr) "offet 0x%" PRIx64
 
 ppc405_gpio_read(uint64_t addr, uint32_t size) "addr 0x%" PRIx64 " size %d"
 ppc405_gpio_write(uint64_t addr, uint32_t size, uint64_t val) "addr 0x%" PRIx64 " size %d = 0x%" PRIx64