xref: /qemu/hw/ppc/spapr_vio.c (revision 814bb12a) 
1 /*
2  * QEMU sPAPR VIO code
3  *
4  * Copyright (c) 2010 David Gibson, IBM Corporation <dwg@au1.ibm.com>
5  * Based on the s390 virtio bus code:
6  * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include "qemu/osdep.h"
23 #include "qemu/error-report.h"
24 #include "qapi/error.h"
25 #include "hw/hw.h"
26 #include "qemu/log.h"
27 #include "sysemu/sysemu.h"
28 #include "hw/boards.h"
29 #include "hw/loader.h"
30 #include "elf.h"
31 #include "hw/sysbus.h"
32 #include "sysemu/kvm.h"
33 #include "sysemu/device_tree.h"
34 #include "kvm_ppc.h"
35 
36 #include "hw/ppc/spapr.h"
37 #include "hw/ppc/spapr_vio.h"
38 #include "hw/ppc/xics.h"
39 #include "trace.h"
40 
41 #include <libfdt.h>
42 
43 static Property spapr_vio_props[] = {
44     DEFINE_PROP_UINT32("irq", VIOsPAPRDevice, irq, 0), \
45     DEFINE_PROP_END_OF_LIST(),
46 };
47 
48 static char *spapr_vio_get_dev_name(DeviceState *qdev)
49 {
50     VIOsPAPRDevice *dev = VIO_SPAPR_DEVICE(qdev);
51     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
52 
53     /* Device tree style name device@reg */
54     return g_strdup_printf("%s@%x", pc->dt_name, dev->reg);
55 }
56 
57 static void spapr_vio_bus_class_init(ObjectClass *klass, void *data)
58 {
59     BusClass *k = BUS_CLASS(klass);
60 
61     k->get_dev_path = spapr_vio_get_dev_name;
62     k->get_fw_dev_path = spapr_vio_get_dev_name;
63 }
64 
65 static const TypeInfo spapr_vio_bus_info = {
66     .name = TYPE_SPAPR_VIO_BUS,
67     .parent = TYPE_BUS,
68     .class_init = spapr_vio_bus_class_init,
69     .instance_size = sizeof(VIOsPAPRBus),
70 };
71 
72 VIOsPAPRDevice *spapr_vio_find_by_reg(VIOsPAPRBus *bus, uint32_t reg)
73 {
74     BusChild *kid;
75     VIOsPAPRDevice *dev = NULL;
76 
77     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
78         dev = (VIOsPAPRDevice *)kid->child;
79         if (dev->reg == reg) {
80             return dev;
81         }
82     }
83 
84     return NULL;
85 }
86 
87 static int vio_make_devnode(VIOsPAPRDevice *dev,
88                             void *fdt)
89 {
90     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
91     int vdevice_off, node_off, ret;
92     char *dt_name;
93 
94     vdevice_off = fdt_path_offset(fdt, "/vdevice");
95     if (vdevice_off < 0) {
96         return vdevice_off;
97     }
98 
99     dt_name = spapr_vio_get_dev_name(DEVICE(dev));
100     node_off = fdt_add_subnode(fdt, vdevice_off, dt_name);
101     g_free(dt_name);
102     if (node_off < 0) {
103         return node_off;
104     }
105 
106     ret = fdt_setprop_cell(fdt, node_off, "reg", dev->reg);
107     if (ret < 0) {
108         return ret;
109     }
110 
111     if (pc->dt_type) {
112         ret = fdt_setprop_string(fdt, node_off, "device_type",
113                                  pc->dt_type);
114         if (ret < 0) {
115             return ret;
116         }
117     }
118 
119     if (pc->dt_compatible) {
120         ret = fdt_setprop_string(fdt, node_off, "compatible",
121                                  pc->dt_compatible);
122         if (ret < 0) {
123             return ret;
124         }
125     }
126 
127     if (dev->irq) {
128         uint32_t ints_prop[] = {cpu_to_be32(dev->irq), 0};
129 
130         ret = fdt_setprop(fdt, node_off, "interrupts", ints_prop,
131                           sizeof(ints_prop));
132         if (ret < 0) {
133             return ret;
134         }
135     }
136 
137     ret = spapr_tcet_dma_dt(fdt, node_off, "ibm,my-dma-window", dev->tcet);
138     if (ret < 0) {
139         return ret;
140     }
141 
142     if (pc->devnode) {
143         ret = (pc->devnode)(dev, fdt, node_off);
144         if (ret < 0) {
145             return ret;
146         }
147     }
148 
149     return node_off;
150 }
151 
152 /*
153  * CRQ handling
154  */
155 static target_ulong h_reg_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
156                               target_ulong opcode, target_ulong *args)
157 {
158     target_ulong reg = args[0];
159     target_ulong queue_addr = args[1];
160     target_ulong queue_len = args[2];
161     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
162 
163     if (!dev) {
164         hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
165         return H_PARAMETER;
166     }
167 
168     /* We can't grok a queue size bigger than 256M for now */
169     if (queue_len < 0x1000 || queue_len > 0x10000000) {
170         hcall_dprintf("Queue size too small or too big (0x" TARGET_FMT_lx
171                       ")\n", queue_len);
172         return H_PARAMETER;
173     }
174 
175     /* Check queue alignment */
176     if (queue_addr & 0xfff) {
177         hcall_dprintf("Queue not aligned (0x" TARGET_FMT_lx ")\n", queue_addr);
178         return H_PARAMETER;
179     }
180 
181     /* Check if device supports CRQs */
182     if (!dev->crq.SendFunc) {
183         hcall_dprintf("Device does not support CRQ\n");
184         return H_NOT_FOUND;
185     }
186 
187     /* Already a queue ? */
188     if (dev->crq.qsize) {
189         hcall_dprintf("CRQ already registered\n");
190         return H_RESOURCE;
191     }
192     dev->crq.qladdr = queue_addr;
193     dev->crq.qsize = queue_len;
194     dev->crq.qnext = 0;
195 
196     trace_spapr_vio_h_reg_crq(reg, queue_addr, queue_len);
197     return H_SUCCESS;
198 }
199 
200 static target_ulong free_crq(VIOsPAPRDevice *dev)
201 {
202     dev->crq.qladdr = 0;
203     dev->crq.qsize = 0;
204     dev->crq.qnext = 0;
205 
206     trace_spapr_vio_free_crq(dev->reg);
207 
208     return H_SUCCESS;
209 }
210 
211 static target_ulong h_free_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
212                                target_ulong opcode, target_ulong *args)
213 {
214     target_ulong reg = args[0];
215     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
216 
217     if (!dev) {
218         hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
219         return H_PARAMETER;
220     }
221 
222     return free_crq(dev);
223 }
224 
225 static target_ulong h_send_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
226                                target_ulong opcode, target_ulong *args)
227 {
228     target_ulong reg = args[0];
229     target_ulong msg_hi = args[1];
230     target_ulong msg_lo = args[2];
231     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
232     uint64_t crq_mangle[2];
233 
234     if (!dev) {
235         hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
236         return H_PARAMETER;
237     }
238     crq_mangle[0] = cpu_to_be64(msg_hi);
239     crq_mangle[1] = cpu_to_be64(msg_lo);
240 
241     if (dev->crq.SendFunc) {
242         return dev->crq.SendFunc(dev, (uint8_t *)crq_mangle);
243     }
244 
245     return H_HARDWARE;
246 }
247 
248 static target_ulong h_enable_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
249                                  target_ulong opcode, target_ulong *args)
250 {
251     target_ulong reg = args[0];
252     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
253 
254     if (!dev) {
255         hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
256         return H_PARAMETER;
257     }
258 
259     return 0;
260 }
261 
262 /* Returns negative error, 0 success, or positive: queue full */
263 int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq)
264 {
265     int rc;
266     uint8_t byte;
267 
268     if (!dev->crq.qsize) {
269         error_report("spapr_vio_send_creq on uninitialized queue");
270         return -1;
271     }
272 
273     /* Maybe do a fast path for KVM just writing to the pages */
274     rc = spapr_vio_dma_read(dev, dev->crq.qladdr + dev->crq.qnext, &byte, 1);
275     if (rc) {
276         return rc;
277     }
278     if (byte != 0) {
279         return 1;
280     }
281 
282     rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext + 8,
283                              &crq[8], 8);
284     if (rc) {
285         return rc;
286     }
287 
288     kvmppc_eieio();
289 
290     rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext, crq, 8);
291     if (rc) {
292         return rc;
293     }
294 
295     dev->crq.qnext = (dev->crq.qnext + 16) % dev->crq.qsize;
296 
297     if (dev->signal_state & 1) {
298         qemu_irq_pulse(spapr_vio_qirq(dev));
299     }
300 
301     return 0;
302 }
303 
304 /* "quiesce" handling */
305 
306 static void spapr_vio_quiesce_one(VIOsPAPRDevice *dev)
307 {
308     if (dev->tcet) {
309         device_reset(DEVICE(dev->tcet));
310     }
311     free_crq(dev);
312 }
313 
314 void spapr_vio_set_bypass(VIOsPAPRDevice *dev, bool bypass)
315 {
316     if (!dev->tcet) {
317         return;
318     }
319 
320     memory_region_set_enabled(&dev->mrbypass, bypass);
321     memory_region_set_enabled(spapr_tce_get_iommu(dev->tcet), !bypass);
322 
323     dev->tcet->bypass = bypass;
324 }
325 
326 static void rtas_set_tce_bypass(PowerPCCPU *cpu, sPAPRMachineState *spapr,
327                                 uint32_t token,
328                                 uint32_t nargs, target_ulong args,
329                                 uint32_t nret, target_ulong rets)
330 {
331     VIOsPAPRBus *bus = spapr->vio_bus;
332     VIOsPAPRDevice *dev;
333     uint32_t unit, enable;
334 
335     if (nargs != 2) {
336         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
337         return;
338     }
339     unit = rtas_ld(args, 0);
340     enable = rtas_ld(args, 1);
341     dev = spapr_vio_find_by_reg(bus, unit);
342     if (!dev) {
343         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
344         return;
345     }
346 
347     if (!dev->tcet) {
348         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
349         return;
350     }
351 
352     spapr_vio_set_bypass(dev, !!enable);
353 
354     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
355 }
356 
357 static void rtas_quiesce(PowerPCCPU *cpu, sPAPRMachineState *spapr,
358                          uint32_t token,
359                          uint32_t nargs, target_ulong args,
360                          uint32_t nret, target_ulong rets)
361 {
362     VIOsPAPRBus *bus = spapr->vio_bus;
363     BusChild *kid;
364     VIOsPAPRDevice *dev = NULL;
365 
366     if (nargs != 0) {
367         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
368         return;
369     }
370 
371     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
372         dev = (VIOsPAPRDevice *)kid->child;
373         spapr_vio_quiesce_one(dev);
374     }
375 
376     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
377 }
378 
379 static VIOsPAPRDevice *reg_conflict(VIOsPAPRDevice *dev)
380 {
381     VIOsPAPRBus *bus = SPAPR_VIO_BUS(dev->qdev.parent_bus);
382     BusChild *kid;
383     VIOsPAPRDevice *other;
384 
385     /*
386      * Check for a device other than the given one which is already
387      * using the requested address. We have to open code this because
388      * the given dev might already be in the list.
389      */
390     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
391         other = VIO_SPAPR_DEVICE(kid->child);
392 
393         if (other != dev && other->reg == dev->reg) {
394             return other;
395         }
396     }
397 
398     return 0;
399 }
400 
401 static void spapr_vio_busdev_reset(DeviceState *qdev)
402 {
403     VIOsPAPRDevice *dev = VIO_SPAPR_DEVICE(qdev);
404     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
405 
406     /* Shut down the request queue and TCEs if necessary */
407     spapr_vio_quiesce_one(dev);
408 
409     dev->signal_state = 0;
410 
411     spapr_vio_set_bypass(dev, false);
412     if (pc->reset) {
413         pc->reset(dev);
414     }
415 }
416 
417 static void spapr_vio_busdev_realize(DeviceState *qdev, Error **errp)
418 {
419     sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
420     VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev;
421     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
422     char *id;
423     Error *local_err = NULL;
424 
425     if (dev->reg != -1) {
426         /*
427          * Explicitly assigned address, just verify that no-one else
428          * is using it.  other mechanism). We have to open code this
429          * rather than using spapr_vio_find_by_reg() because sdev
430          * itself is already in the list.
431          */
432         VIOsPAPRDevice *other = reg_conflict(dev);
433 
434         if (other) {
435             error_setg(errp, "%s and %s devices conflict at address %#x",
436                        object_get_typename(OBJECT(qdev)),
437                        object_get_typename(OBJECT(&other->qdev)),
438                        dev->reg);
439             return;
440         }
441     } else {
442         /* Need to assign an address */
443         VIOsPAPRBus *bus = SPAPR_VIO_BUS(dev->qdev.parent_bus);
444 
445         do {
446             dev->reg = bus->next_reg++;
447         } while (reg_conflict(dev));
448     }
449 
450     /* Don't overwrite ids assigned on the command line */
451     if (!dev->qdev.id) {
452         id = spapr_vio_get_dev_name(DEVICE(dev));
453         dev->qdev.id = id;
454     }
455 
456     dev->irq = xics_spapr_alloc(spapr->xics, dev->irq, false, &local_err);
457     if (local_err) {
458         error_propagate(errp, local_err);
459         return;
460     }
461 
462     if (pc->rtce_window_size) {
463         uint32_t liobn = SPAPR_VIO_LIOBN(dev->reg);
464 
465         memory_region_init(&dev->mrroot, OBJECT(dev), "iommu-spapr-root",
466                            ram_size);
467         memory_region_init_alias(&dev->mrbypass, OBJECT(dev),
468                                  "iommu-spapr-bypass", get_system_memory(),
469                                  0, ram_size);
470         memory_region_add_subregion_overlap(&dev->mrroot, 0, &dev->mrbypass, 1);
471         address_space_init(&dev->as, &dev->mrroot, qdev->id);
472 
473         dev->tcet = spapr_tce_new_table(qdev, liobn);
474         spapr_tce_table_enable(dev->tcet, SPAPR_TCE_PAGE_SHIFT, 0,
475                                pc->rtce_window_size >> SPAPR_TCE_PAGE_SHIFT);
476         dev->tcet->vdev = dev;
477         memory_region_add_subregion_overlap(&dev->mrroot, 0,
478                                             spapr_tce_get_iommu(dev->tcet), 2);
479     }
480 
481     pc->realize(dev, errp);
482 }
483 
484 static target_ulong h_vio_signal(PowerPCCPU *cpu, sPAPRMachineState *spapr,
485                                  target_ulong opcode,
486                                  target_ulong *args)
487 {
488     target_ulong reg = args[0];
489     target_ulong mode = args[1];
490     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
491     VIOsPAPRDeviceClass *pc;
492 
493     if (!dev) {
494         return H_PARAMETER;
495     }
496 
497     pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
498 
499     if (mode & ~pc->signal_mask) {
500         return H_PARAMETER;
501     }
502 
503     dev->signal_state = mode;
504 
505     return H_SUCCESS;
506 }
507 
508 VIOsPAPRBus *spapr_vio_bus_init(void)
509 {
510     VIOsPAPRBus *bus;
511     BusState *qbus;
512     DeviceState *dev;
513 
514     /* Create bridge device */
515     dev = qdev_create(NULL, TYPE_SPAPR_VIO_BRIDGE);
516     qdev_init_nofail(dev);
517 
518     /* Create bus on bridge device */
519     qbus = qbus_create(TYPE_SPAPR_VIO_BUS, dev, "spapr-vio");
520     bus = SPAPR_VIO_BUS(qbus);
521     bus->next_reg = 0x71000000;
522 
523     /* hcall-vio */
524     spapr_register_hypercall(H_VIO_SIGNAL, h_vio_signal);
525 
526     /* hcall-crq */
527     spapr_register_hypercall(H_REG_CRQ, h_reg_crq);
528     spapr_register_hypercall(H_FREE_CRQ, h_free_crq);
529     spapr_register_hypercall(H_SEND_CRQ, h_send_crq);
530     spapr_register_hypercall(H_ENABLE_CRQ, h_enable_crq);
531 
532     /* RTAS calls */
533     spapr_rtas_register(RTAS_IBM_SET_TCE_BYPASS, "ibm,set-tce-bypass",
534                         rtas_set_tce_bypass);
535     spapr_rtas_register(RTAS_QUIESCE, "quiesce", rtas_quiesce);
536 
537     return bus;
538 }
539 
540 /* Represents sPAPR hcall VIO devices */
541 
542 static int spapr_vio_bridge_init(SysBusDevice *dev)
543 {
544     /* nothing */
545     return 0;
546 }
547 
548 static void spapr_vio_bridge_class_init(ObjectClass *klass, void *data)
549 {
550     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
551     DeviceClass *dc = DEVICE_CLASS(klass);
552 
553     dc->fw_name = "vdevice";
554     k->init = spapr_vio_bridge_init;
555 }
556 
557 static const TypeInfo spapr_vio_bridge_info = {
558     .name          = TYPE_SPAPR_VIO_BRIDGE,
559     .parent        = TYPE_SYS_BUS_DEVICE,
560     .class_init    = spapr_vio_bridge_class_init,
561 };
562 
563 const VMStateDescription vmstate_spapr_vio = {
564     .name = "spapr_vio",
565     .version_id = 1,
566     .minimum_version_id = 1,
567     .fields = (VMStateField[]) {
568         /* Sanity check */
569         VMSTATE_UINT32_EQUAL(reg, VIOsPAPRDevice),
570         VMSTATE_UINT32_EQUAL(irq, VIOsPAPRDevice),
571 
572         /* General VIO device state */
573         VMSTATE_UINT64(signal_state, VIOsPAPRDevice),
574         VMSTATE_UINT64(crq.qladdr, VIOsPAPRDevice),
575         VMSTATE_UINT32(crq.qsize, VIOsPAPRDevice),
576         VMSTATE_UINT32(crq.qnext, VIOsPAPRDevice),
577 
578         VMSTATE_END_OF_LIST()
579     },
580 };
581 
582 static void vio_spapr_device_class_init(ObjectClass *klass, void *data)
583 {
584     DeviceClass *k = DEVICE_CLASS(klass);
585     k->realize = spapr_vio_busdev_realize;
586     k->reset = spapr_vio_busdev_reset;
587     k->bus_type = TYPE_SPAPR_VIO_BUS;
588     k->props = spapr_vio_props;
589 }
590 
591 static const TypeInfo spapr_vio_type_info = {
592     .name = TYPE_VIO_SPAPR_DEVICE,
593     .parent = TYPE_DEVICE,
594     .instance_size = sizeof(VIOsPAPRDevice),
595     .abstract = true,
596     .class_size = sizeof(VIOsPAPRDeviceClass),
597     .class_init = vio_spapr_device_class_init,
598 };
599 
600 static void spapr_vio_register_types(void)
601 {
602     type_register_static(&spapr_vio_bus_info);
603     type_register_static(&spapr_vio_bridge_info);
604     type_register_static(&spapr_vio_type_info);
605 }
606 
607 type_init(spapr_vio_register_types)
608 
609 static int compare_reg(const void *p1, const void *p2)
610 {
611     VIOsPAPRDevice const *dev1, *dev2;
612 
613     dev1 = (VIOsPAPRDevice *)*(DeviceState **)p1;
614     dev2 = (VIOsPAPRDevice *)*(DeviceState **)p2;
615 
616     if (dev1->reg < dev2->reg) {
617         return -1;
618     }
619     if (dev1->reg == dev2->reg) {
620         return 0;
621     }
622 
623     /* dev1->reg > dev2->reg */
624     return 1;
625 }
626 
627 int spapr_populate_vdevice(VIOsPAPRBus *bus, void *fdt)
628 {
629     DeviceState *qdev, **qdevs;
630     BusChild *kid;
631     int i, num, ret = 0;
632 
633     /* Count qdevs on the bus list */
634     num = 0;
635     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
636         num++;
637     }
638 
639     /* Copy out into an array of pointers */
640     qdevs = g_malloc(sizeof(qdev) * num);
641     num = 0;
642     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
643         qdevs[num++] = kid->child;
644     }
645 
646     /* Sort the array */
647     qsort(qdevs, num, sizeof(qdev), compare_reg);
648 
649     /* Hack alert. Give the devices to libfdt in reverse order, we happen
650      * to know that will mean they are in forward order in the tree. */
651     for (i = num - 1; i >= 0; i--) {
652         VIOsPAPRDevice *dev = (VIOsPAPRDevice *)(qdevs[i]);
653 
654         ret = vio_make_devnode(dev, fdt);
655 
656         if (ret < 0) {
657             goto out;
658         }
659     }
660 
661     ret = 0;
662 out:
663     g_free(qdevs);
664 
665     return ret;
666 }
667 
668 int spapr_populate_chosen_stdout(void *fdt, VIOsPAPRBus *bus)
669 {
670     VIOsPAPRDevice *dev;
671     char *name, *path;
672     int ret, offset;
673 
674     dev = spapr_vty_get_default(bus);
675     if (!dev)
676         return 0;
677 
678     offset = fdt_path_offset(fdt, "/chosen");
679     if (offset < 0) {
680         return offset;
681     }
682 
683     name = spapr_vio_get_dev_name(DEVICE(dev));
684     path = g_strdup_printf("/vdevice/%s", name);
685 
686     ret = fdt_setprop_string(fdt, offset, "linux,stdout-path", path);
687 
688     g_free(name);
689     g_free(path);
690 
691     return ret;
692 }
693