hw/misc/bcm2835_property.c - third_party/qemu - Git at Google

 /*
  * Raspberry Pi emulation (c) 2012 Gregory Estrade
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */

 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "hw/misc/bcm2835_property.h"
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 #include "hw/irq.h"
 #include "hw/misc/bcm2835_mbox_defs.h"
 #include "sysemu/dma.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
 #include "trace.h"

 /* https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface */

 static void bcm2835_property_mbox_push(BCM2835PropertyState *s, uint32_t value)
 {
     uint32_t tag;
     uint32_t bufsize;
     uint32_t tot_len;
     size_t resplen;
     uint32_t tmp;
     int n;
     uint32_t offset, length, color;

     /*
      * Copy the current state of the framebuffer config; we will update
      * this copy as we process tags and then ask the framebuffer to use
      * it at the end.
      */
     BCM2835FBConfig fbconfig = s->fbdev->config;
     bool fbconfig_updated = false;

     value &= ~0xf;

     s->addr = value;

     tot_len = ldl_le_phys(&s->dma_as, value);

     /* @(addr + 4) : Buffer response code */
     value = s->addr + 8;
     while (value + 8 <= s->addr + tot_len) {
         tag = ldl_le_phys(&s->dma_as, value);
         bufsize = ldl_le_phys(&s->dma_as, value + 4);
         /* @(value + 8) : Request/response indicator */
         resplen = 0;
         switch (tag) {
         case 0x00000000: /* End tag */
             break;
         case 0x00000001: /* Get firmware revision */
             stl_le_phys(&s->dma_as, value + 12, 346337);
             resplen = 4;
             break;
         case 0x00010001: /* Get board model */
             qemu_log_mask(LOG_UNIMP,
                           "bcm2835_property: 0x%08x get board model NYI\n",
                           tag);
             resplen = 4;
             break;
         case 0x00010002: /* Get board revision */
             stl_le_phys(&s->dma_as, value + 12, s->board_rev);
             resplen = 4;
             break;
         case 0x00010003: /* Get board MAC address */
             resplen = sizeof(s->macaddr.a);
             dma_memory_write(&s->dma_as, value + 12, s->macaddr.a, resplen,
                              MEMTXATTRS_UNSPECIFIED);
             break;
         case 0x00010004: /* Get board serial */
             qemu_log_mask(LOG_UNIMP,
                           "bcm2835_property: 0x%08x get board serial NYI\n",
                           tag);
             resplen = 8;
             break;
         case 0x00010005: /* Get ARM memory */
             /* base */
             stl_le_phys(&s->dma_as, value + 12, 0);
             /* size */
             stl_le_phys(&s->dma_as, value + 16, s->fbdev->vcram_base);
             resplen = 8;
             break;
         case 0x00010006: /* Get VC memory */
             /* base */
             stl_le_phys(&s->dma_as, value + 12, s->fbdev->vcram_base);
             /* size */
             stl_le_phys(&s->dma_as, value + 16, s->fbdev->vcram_size);
             resplen = 8;
             break;
         case 0x00028001: /* Set power state */
             /* Assume that whatever device they asked for exists,
              * and we'll just claim we set it to the desired state
              */
             tmp = ldl_le_phys(&s->dma_as, value + 16);
             stl_le_phys(&s->dma_as, value + 16, (tmp & 1));
             resplen = 8;
             break;

         /* Clocks */

         case 0x00030001: /* Get clock state */
             stl_le_phys(&s->dma_as, value + 16, 0x1);
             resplen = 8;
             break;

         case 0x00038001: /* Set clock state */
             qemu_log_mask(LOG_UNIMP,
                           "bcm2835_property: 0x%08x set clock state NYI\n",
                           tag);
             resplen = 8;
             break;

         case 0x00030002: /* Get clock rate */
         case 0x00030004: /* Get max clock rate */
         case 0x00030007: /* Get min clock rate */
             switch (ldl_le_phys(&s->dma_as, value + 12)) {
             case 1: /* EMMC */
                 stl_le_phys(&s->dma_as, value + 16, 50000000);
                 break;
             case 2: /* UART */
                 stl_le_phys(&s->dma_as, value + 16, 3000000);
                 break;
             default:
                 stl_le_phys(&s->dma_as, value + 16, 700000000);
                 break;
             }
             resplen = 8;
             break;

         case 0x00038002: /* Set clock rate */
         case 0x00038004: /* Set max clock rate */
         case 0x00038007: /* Set min clock rate */
             qemu_log_mask(LOG_UNIMP,
                           "bcm2835_property: 0x%08x set clock rate NYI\n",
                           tag);
             resplen = 8;
             break;

         /* Temperature */

         case 0x00030006: /* Get temperature */
             stl_le_phys(&s->dma_as, value + 16, 25000);
             resplen = 8;
             break;

         case 0x0003000A: /* Get max temperature */
             stl_le_phys(&s->dma_as, value + 16, 99000);
             resplen = 8;
             break;

         /* Frame buffer */

         case 0x00040001: /* Allocate buffer */
             stl_le_phys(&s->dma_as, value + 12, fbconfig.base);
             stl_le_phys(&s->dma_as, value + 16,
                         bcm2835_fb_get_size(&fbconfig));
             resplen = 8;
             break;
         case 0x00048001: /* Release buffer */
             resplen = 0;
             break;
         case 0x00040002: /* Blank screen */
             resplen = 4;
             break;
         case 0x00044003: /* Test physical display width/height */
         case 0x00044004: /* Test virtual display width/height */
             resplen = 8;
             break;
         case 0x00048003: /* Set physical display width/height */
             fbconfig.xres = ldl_le_phys(&s->dma_as, value + 12);
             fbconfig.yres = ldl_le_phys(&s->dma_as, value + 16);
             bcm2835_fb_validate_config(&fbconfig);
             fbconfig_updated = true;
             /* fall through */
         case 0x00040003: /* Get physical display width/height */
             stl_le_phys(&s->dma_as, value + 12, fbconfig.xres);
             stl_le_phys(&s->dma_as, value + 16, fbconfig.yres);
             resplen = 8;
             break;
         case 0x00048004: /* Set virtual display width/height */
             fbconfig.xres_virtual = ldl_le_phys(&s->dma_as, value + 12);
             fbconfig.yres_virtual = ldl_le_phys(&s->dma_as, value + 16);
             bcm2835_fb_validate_config(&fbconfig);
             fbconfig_updated = true;
             /* fall through */
         case 0x00040004: /* Get virtual display width/height */
             stl_le_phys(&s->dma_as, value + 12, fbconfig.xres_virtual);
             stl_le_phys(&s->dma_as, value + 16, fbconfig.yres_virtual);
             resplen = 8;
             break;
         case 0x00044005: /* Test depth */
             resplen = 4;
             break;
         case 0x00048005: /* Set depth */
             fbconfig.bpp = ldl_le_phys(&s->dma_as, value + 12);
             bcm2835_fb_validate_config(&fbconfig);
             fbconfig_updated = true;
             /* fall through */
         case 0x00040005: /* Get depth */
             stl_le_phys(&s->dma_as, value + 12, fbconfig.bpp);
             resplen = 4;
             break;
         case 0x00044006: /* Test pixel order */
             resplen = 4;
             break;
         case 0x00048006: /* Set pixel order */
             fbconfig.pixo = ldl_le_phys(&s->dma_as, value + 12);
             bcm2835_fb_validate_config(&fbconfig);
             fbconfig_updated = true;
             /* fall through */
         case 0x00040006: /* Get pixel order */
             stl_le_phys(&s->dma_as, value + 12, fbconfig.pixo);
             resplen = 4;
             break;
         case 0x00044007: /* Test pixel alpha */
             resplen = 4;
             break;
         case 0x00048007: /* Set alpha */
             fbconfig.alpha = ldl_le_phys(&s->dma_as, value + 12);
             bcm2835_fb_validate_config(&fbconfig);
             fbconfig_updated = true;
             /* fall through */
         case 0x00040007: /* Get alpha */
             stl_le_phys(&s->dma_as, value + 12, fbconfig.alpha);
             resplen = 4;
             break;
         case 0x00040008: /* Get pitch */
             stl_le_phys(&s->dma_as, value + 12,
                         bcm2835_fb_get_pitch(&fbconfig));
             resplen = 4;
             break;
         case 0x00044009: /* Test virtual offset */
             resplen = 8;
             break;
         case 0x00048009: /* Set virtual offset */
             fbconfig.xoffset = ldl_le_phys(&s->dma_as, value + 12);
             fbconfig.yoffset = ldl_le_phys(&s->dma_as, value + 16);
             bcm2835_fb_validate_config(&fbconfig);
             fbconfig_updated = true;
             /* fall through */
         case 0x00040009: /* Get virtual offset */
             stl_le_phys(&s->dma_as, value + 12, fbconfig.xoffset);
             stl_le_phys(&s->dma_as, value + 16, fbconfig.yoffset);
             resplen = 8;
             break;
         case 0x0004000a: /* Get/Test/Set overscan */
         case 0x0004400a:
         case 0x0004800a:
             stl_le_phys(&s->dma_as, value + 12, 0);
             stl_le_phys(&s->dma_as, value + 16, 0);
             stl_le_phys(&s->dma_as, value + 20, 0);
             stl_le_phys(&s->dma_as, value + 24, 0);
             resplen = 16;
             break;
         case 0x0004800b: /* Set palette */
             offset = ldl_le_phys(&s->dma_as, value + 12);
             length = ldl_le_phys(&s->dma_as, value + 16);
             n = 0;
             while (n < length - offset) {
                 color = ldl_le_phys(&s->dma_as, value + 20 + (n << 2));
                 stl_le_phys(&s->dma_as,
                             s->fbdev->vcram_base + ((offset + n) << 2), color);
                 n++;
             }
             stl_le_phys(&s->dma_as, value + 12, 0);
             resplen = 4;
             break;

         case 0x00060001: /* Get DMA channels */
             /* channels 2-5 */
             stl_le_phys(&s->dma_as, value + 12, 0x003C);
             resplen = 4;
             break;

         case 0x00050001: /* Get command line */
             resplen = 0;
             break;

         default:
             qemu_log_mask(LOG_UNIMP,
                           "bcm2835_property: unhandled tag 0x%08x\n", tag);
             break;
         }

         trace_bcm2835_mbox_property(tag, bufsize, resplen);
         if (tag == 0) {
             break;
         }

         stl_le_phys(&s->dma_as, value + 8, (1 << 31) | resplen);
         value += bufsize + 12;
     }

     /* Reconfigure framebuffer if required */
     if (fbconfig_updated) {
         bcm2835_fb_reconfigure(s->fbdev, &fbconfig);
     }

     /* Buffer response code */
     stl_le_phys(&s->dma_as, s->addr + 4, (1 << 31));
 }

 static uint64_t bcm2835_property_read(void *opaque, hwaddr offset,
                                       unsigned size)
 {
     BCM2835PropertyState *s = opaque;
     uint32_t res = 0;

     switch (offset) {
     case MBOX_AS_DATA:
         res = MBOX_CHAN_PROPERTY | s->addr;
         s->pending = false;
         qemu_set_irq(s->mbox_irq, 0);
         break;

     case MBOX_AS_PENDING:
         res = s->pending;
         break;

     default:
         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
                       __func__, offset);
         return 0;
     }

     return res;
 }

 static void bcm2835_property_write(void *opaque, hwaddr offset,
                                    uint64_t value, unsigned size)
 {
     BCM2835PropertyState *s = opaque;

     switch (offset) {
     case MBOX_AS_DATA:
         /* bcm2835_mbox should check our pending status before pushing */
         assert(!s->pending);
         s->pending = true;
         bcm2835_property_mbox_push(s, value);
         qemu_set_irq(s->mbox_irq, 1);
         break;

     default:
         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
                       __func__, offset);
         return;
     }
 }

 static const MemoryRegionOps bcm2835_property_ops = {
     .read = bcm2835_property_read,
     .write = bcm2835_property_write,
     .endianness = DEVICE_NATIVE_ENDIAN,
     .valid.min_access_size = 4,
     .valid.max_access_size = 4,
 };

 static const VMStateDescription vmstate_bcm2835_property = {
     .name = TYPE_BCM2835_PROPERTY,
     .version_id = 1,
     .minimum_version_id = 1,
     .fields      = (VMStateField[]) {
         VMSTATE_MACADDR(macaddr, BCM2835PropertyState),
         VMSTATE_UINT32(addr, BCM2835PropertyState),
         VMSTATE_BOOL(pending, BCM2835PropertyState),
         VMSTATE_END_OF_LIST()
     }
 };

 static void bcm2835_property_init(Object *obj)
 {
     BCM2835PropertyState *s = BCM2835_PROPERTY(obj);

     memory_region_init_io(&s->iomem, OBJECT(s), &bcm2835_property_ops, s,
                           TYPE_BCM2835_PROPERTY, 0x10);
     sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
     sysbus_init_irq(SYS_BUS_DEVICE(s), &s->mbox_irq);
 }

 static void bcm2835_property_reset(DeviceState *dev)
 {
     BCM2835PropertyState *s = BCM2835_PROPERTY(dev);

     s->pending = false;
 }

 static void bcm2835_property_realize(DeviceState *dev, Error **errp)
 {
     BCM2835PropertyState *s = BCM2835_PROPERTY(dev);
     Object *obj;

     obj = object_property_get_link(OBJECT(dev), "fb", &error_abort);
     s->fbdev = BCM2835_FB(obj);

     obj = object_property_get_link(OBJECT(dev), "dma-mr", &error_abort);
     s->dma_mr = MEMORY_REGION(obj);
     address_space_init(&s->dma_as, s->dma_mr, TYPE_BCM2835_PROPERTY "-memory");

     /* TODO: connect to MAC address of USB NIC device, once we emulate it */
     qemu_macaddr_default_if_unset(&s->macaddr);

     bcm2835_property_reset(dev);
 }

 static Property bcm2835_property_props[] = {
     DEFINE_PROP_UINT32("board-rev", BCM2835PropertyState, board_rev, 0),
     DEFINE_PROP_END_OF_LIST()
 };

 static void bcm2835_property_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

     device_class_set_props(dc, bcm2835_property_props);
     dc->realize = bcm2835_property_realize;
     dc->vmsd = &vmstate_bcm2835_property;
 }

 static const TypeInfo bcm2835_property_info = {
     .name          = TYPE_BCM2835_PROPERTY,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(BCM2835PropertyState),
     .class_init    = bcm2835_property_class_init,
     .instance_init = bcm2835_property_init,
 };

 static void bcm2835_property_register_types(void)
 {
     type_register_static(&bcm2835_property_info);
 }

 type_init(bcm2835_property_register_types)
	/*
	* Raspberry Pi emulation (c) 2012 Gregory Estrade
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or later.
	* See the COPYING file in the top-level directory.
	*/

	#include "qemu/osdep.h"
	#include "qapi/error.h"
	#include "hw/misc/bcm2835_property.h"
	#include "hw/qdev-properties.h"
	#include "migration/vmstate.h"
	#include "hw/irq.h"
	#include "hw/misc/bcm2835_mbox_defs.h"
	#include "sysemu/dma.h"
	#include "qemu/log.h"
	#include "qemu/module.h"
	#include "trace.h"

	/* https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface */

	static void bcm2835_property_mbox_push(BCM2835PropertyState *s, uint32_t value)
	{
	uint32_t tag;
	uint32_t bufsize;
	uint32_t tot_len;
	size_t resplen;
	uint32_t tmp;
	int n;
	uint32_t offset, length, color;

	/*
	* Copy the current state of the framebuffer config; we will update
	* this copy as we process tags and then ask the framebuffer to use
	* it at the end.
	*/
	BCM2835FBConfig fbconfig = s->fbdev->config;
	bool fbconfig_updated = false;

	value &= ~0xf;

	s->addr = value;

	tot_len = ldl_le_phys(&s->dma_as, value);

	/* @(addr + 4) : Buffer response code */
	value = s->addr + 8;
	while (value + 8 <= s->addr + tot_len) {
	tag = ldl_le_phys(&s->dma_as, value);
	bufsize = ldl_le_phys(&s->dma_as, value + 4);
	/* @(value + 8) : Request/response indicator */
	resplen = 0;
	switch (tag) {
	case 0x00000000: /* End tag */
	break;
	case 0x00000001: /* Get firmware revision */
	stl_le_phys(&s->dma_as, value + 12, 346337);
	resplen = 4;
	break;
	case 0x00010001: /* Get board model */
	qemu_log_mask(LOG_UNIMP,
	"bcm2835_property: 0x%08x get board model NYI\n",
	tag);
	resplen = 4;
	break;
	case 0x00010002: /* Get board revision */
	stl_le_phys(&s->dma_as, value + 12, s->board_rev);
	resplen = 4;
	break;
	case 0x00010003: /* Get board MAC address */
	resplen = sizeof(s->macaddr.a);
	dma_memory_write(&s->dma_as, value + 12, s->macaddr.a, resplen,
	MEMTXATTRS_UNSPECIFIED);
	break;
	case 0x00010004: /* Get board serial */
	qemu_log_mask(LOG_UNIMP,
	"bcm2835_property: 0x%08x get board serial NYI\n",
	tag);
	resplen = 8;
	break;
	case 0x00010005: /* Get ARM memory */
	/* base */
	stl_le_phys(&s->dma_as, value + 12, 0);
	/* size */
	stl_le_phys(&s->dma_as, value + 16, s->fbdev->vcram_base);
	resplen = 8;
	break;
	case 0x00010006: /* Get VC memory */
	/* base */
	stl_le_phys(&s->dma_as, value + 12, s->fbdev->vcram_base);
	/* size */
	stl_le_phys(&s->dma_as, value + 16, s->fbdev->vcram_size);
	resplen = 8;
	break;
	case 0x00028001: /* Set power state */
	/* Assume that whatever device they asked for exists,
	* and we'll just claim we set it to the desired state
	*/
	tmp = ldl_le_phys(&s->dma_as, value + 16);
	stl_le_phys(&s->dma_as, value + 16, (tmp & 1));
	resplen = 8;
	break;

	/* Clocks */

	case 0x00030001: /* Get clock state */
	stl_le_phys(&s->dma_as, value + 16, 0x1);
	resplen = 8;
	break;

	case 0x00038001: /* Set clock state */
	qemu_log_mask(LOG_UNIMP,
	"bcm2835_property: 0x%08x set clock state NYI\n",
	tag);
	resplen = 8;
	break;

	case 0x00030002: /* Get clock rate */
	case 0x00030004: /* Get max clock rate */
	case 0x00030007: /* Get min clock rate */
	switch (ldl_le_phys(&s->dma_as, value + 12)) {
	case 1: /* EMMC */
	stl_le_phys(&s->dma_as, value + 16, 50000000);
	break;
	case 2: /* UART */
	stl_le_phys(&s->dma_as, value + 16, 3000000);
	break;
	default:
	stl_le_phys(&s->dma_as, value + 16, 700000000);
	break;
	}
	resplen = 8;
	break;

	case 0x00038002: /* Set clock rate */
	case 0x00038004: /* Set max clock rate */
	case 0x00038007: /* Set min clock rate */
	qemu_log_mask(LOG_UNIMP,
	"bcm2835_property: 0x%08x set clock rate NYI\n",
	tag);
	resplen = 8;
	break;

	/* Temperature */

	case 0x00030006: /* Get temperature */
	stl_le_phys(&s->dma_as, value + 16, 25000);
	resplen = 8;
	break;

	case 0x0003000A: /* Get max temperature */
	stl_le_phys(&s->dma_as, value + 16, 99000);
	resplen = 8;
	break;

	/* Frame buffer */

	case 0x00040001: /* Allocate buffer */
	stl_le_phys(&s->dma_as, value + 12, fbconfig.base);
	stl_le_phys(&s->dma_as, value + 16,
	bcm2835_fb_get_size(&fbconfig));
	resplen = 8;
	break;
	case 0x00048001: /* Release buffer */
	resplen = 0;
	break;
	case 0x00040002: /* Blank screen */
	resplen = 4;
	break;
	case 0x00044003: /* Test physical display width/height */
	case 0x00044004: /* Test virtual display width/height */
	resplen = 8;
	break;
	case 0x00048003: /* Set physical display width/height */
	fbconfig.xres = ldl_le_phys(&s->dma_as, value + 12);
	fbconfig.yres = ldl_le_phys(&s->dma_as, value + 16);
	bcm2835_fb_validate_config(&fbconfig);
	fbconfig_updated = true;
	/* fall through */
	case 0x00040003: /* Get physical display width/height */
	stl_le_phys(&s->dma_as, value + 12, fbconfig.xres);
	stl_le_phys(&s->dma_as, value + 16, fbconfig.yres);
	resplen = 8;
	break;
	case 0x00048004: /* Set virtual display width/height */
	fbconfig.xres_virtual = ldl_le_phys(&s->dma_as, value + 12);
	fbconfig.yres_virtual = ldl_le_phys(&s->dma_as, value + 16);
	bcm2835_fb_validate_config(&fbconfig);
	fbconfig_updated = true;
	/* fall through */
	case 0x00040004: /* Get virtual display width/height */
	stl_le_phys(&s->dma_as, value + 12, fbconfig.xres_virtual);
	stl_le_phys(&s->dma_as, value + 16, fbconfig.yres_virtual);
	resplen = 8;
	break;
	case 0x00044005: /* Test depth */
	resplen = 4;
	break;
	case 0x00048005: /* Set depth */
	fbconfig.bpp = ldl_le_phys(&s->dma_as, value + 12);
	bcm2835_fb_validate_config(&fbconfig);
	fbconfig_updated = true;
	/* fall through */
	case 0x00040005: /* Get depth */
	stl_le_phys(&s->dma_as, value + 12, fbconfig.bpp);
	resplen = 4;
	break;
	case 0x00044006: /* Test pixel order */
	resplen = 4;
	break;
	case 0x00048006: /* Set pixel order */
	fbconfig.pixo = ldl_le_phys(&s->dma_as, value + 12);
	bcm2835_fb_validate_config(&fbconfig);
	fbconfig_updated = true;
	/* fall through */
	case 0x00040006: /* Get pixel order */
	stl_le_phys(&s->dma_as, value + 12, fbconfig.pixo);
	resplen = 4;
	break;
	case 0x00044007: /* Test pixel alpha */
	resplen = 4;
	break;
	case 0x00048007: /* Set alpha */
	fbconfig.alpha = ldl_le_phys(&s->dma_as, value + 12);
	bcm2835_fb_validate_config(&fbconfig);
	fbconfig_updated = true;
	/* fall through */
	case 0x00040007: /* Get alpha */
	stl_le_phys(&s->dma_as, value + 12, fbconfig.alpha);
	resplen = 4;
	break;
	case 0x00040008: /* Get pitch */
	stl_le_phys(&s->dma_as, value + 12,
	bcm2835_fb_get_pitch(&fbconfig));
	resplen = 4;
	break;
	case 0x00044009: /* Test virtual offset */
	resplen = 8;
	break;
	case 0x00048009: /* Set virtual offset */
	fbconfig.xoffset = ldl_le_phys(&s->dma_as, value + 12);
	fbconfig.yoffset = ldl_le_phys(&s->dma_as, value + 16);
	bcm2835_fb_validate_config(&fbconfig);
	fbconfig_updated = true;
	/* fall through */
	case 0x00040009: /* Get virtual offset */
	stl_le_phys(&s->dma_as, value + 12, fbconfig.xoffset);
	stl_le_phys(&s->dma_as, value + 16, fbconfig.yoffset);
	resplen = 8;
	break;
	case 0x0004000a: /* Get/Test/Set overscan */
	case 0x0004400a:
	case 0x0004800a:
	stl_le_phys(&s->dma_as, value + 12, 0);
	stl_le_phys(&s->dma_as, value + 16, 0);
	stl_le_phys(&s->dma_as, value + 20, 0);
	stl_le_phys(&s->dma_as, value + 24, 0);
	resplen = 16;
	break;
	case 0x0004800b: /* Set palette */
	offset = ldl_le_phys(&s->dma_as, value + 12);
	length = ldl_le_phys(&s->dma_as, value + 16);
	n = 0;
	while (n < length - offset) {
	color = ldl_le_phys(&s->dma_as, value + 20 + (n << 2));
	stl_le_phys(&s->dma_as,
	s->fbdev->vcram_base + ((offset + n) << 2), color);
	n++;
	}
	stl_le_phys(&s->dma_as, value + 12, 0);
	resplen = 4;
	break;

	case 0x00060001: /* Get DMA channels */
	/* channels 2-5 */
	stl_le_phys(&s->dma_as, value + 12, 0x003C);
	resplen = 4;
	break;

	case 0x00050001: /* Get command line */
	resplen = 0;
	break;

	default:
	qemu_log_mask(LOG_UNIMP,
	"bcm2835_property: unhandled tag 0x%08x\n", tag);
	break;
	}

	trace_bcm2835_mbox_property(tag, bufsize, resplen);
	if (tag == 0) {
	break;
	}

	stl_le_phys(&s->dma_as, value + 8, (1 << 31) \| resplen);
	value += bufsize + 12;
	}

	/* Reconfigure framebuffer if required */
	if (fbconfig_updated) {
	bcm2835_fb_reconfigure(s->fbdev, &fbconfig);
	}

	/* Buffer response code */
	stl_le_phys(&s->dma_as, s->addr + 4, (1 << 31));
	}

	static uint64_t bcm2835_property_read(void *opaque, hwaddr offset,
	unsigned size)
	{
	BCM2835PropertyState *s = opaque;
	uint32_t res = 0;

	switch (offset) {
	case MBOX_AS_DATA:
	res = MBOX_CHAN_PROPERTY \| s->addr;
	s->pending = false;
	qemu_set_irq(s->mbox_irq, 0);
	break;

	case MBOX_AS_PENDING:
	res = s->pending;
	break;

	default:
	qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
	__func__, offset);
	return 0;
	}

	return res;
	}

	static void bcm2835_property_write(void *opaque, hwaddr offset,
	uint64_t value, unsigned size)
	{
	BCM2835PropertyState *s = opaque;

	switch (offset) {
	case MBOX_AS_DATA:
	/* bcm2835_mbox should check our pending status before pushing */
	assert(!s->pending);
	s->pending = true;
	bcm2835_property_mbox_push(s, value);
	qemu_set_irq(s->mbox_irq, 1);
	break;

	default:
	qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
	__func__, offset);
	return;
	}
	}

	static const MemoryRegionOps bcm2835_property_ops = {
	.read = bcm2835_property_read,
	.write = bcm2835_property_write,
	.endianness = DEVICE_NATIVE_ENDIAN,
	.valid.min_access_size = 4,
	.valid.max_access_size = 4,
	};

	static const VMStateDescription vmstate_bcm2835_property = {
	.name = TYPE_BCM2835_PROPERTY,
	.version_id = 1,
	.minimum_version_id = 1,
	.fields = (VMStateField[]) {
	VMSTATE_MACADDR(macaddr, BCM2835PropertyState),
	VMSTATE_UINT32(addr, BCM2835PropertyState),
	VMSTATE_BOOL(pending, BCM2835PropertyState),
	VMSTATE_END_OF_LIST()
	}
	};

	static void bcm2835_property_init(Object *obj)
	{
	BCM2835PropertyState *s = BCM2835_PROPERTY(obj);

	memory_region_init_io(&s->iomem, OBJECT(s), &bcm2835_property_ops, s,
	TYPE_BCM2835_PROPERTY, 0x10);
	sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
	sysbus_init_irq(SYS_BUS_DEVICE(s), &s->mbox_irq);
	}

	static void bcm2835_property_reset(DeviceState *dev)
	{
	BCM2835PropertyState *s = BCM2835_PROPERTY(dev);

	s->pending = false;
	}

	static void bcm2835_property_realize(DeviceState dev, Error *errp)
	{
	BCM2835PropertyState *s = BCM2835_PROPERTY(dev);
	Object *obj;

	obj = object_property_get_link(OBJECT(dev), "fb", &error_abort);
	s->fbdev = BCM2835_FB(obj);

	obj = object_property_get_link(OBJECT(dev), "dma-mr", &error_abort);
	s->dma_mr = MEMORY_REGION(obj);
	address_space_init(&s->dma_as, s->dma_mr, TYPE_BCM2835_PROPERTY "-memory");

	/* TODO: connect to MAC address of USB NIC device, once we emulate it */
	qemu_macaddr_default_if_unset(&s->macaddr);

	bcm2835_property_reset(dev);
	}

	static Property bcm2835_property_props[] = {
	DEFINE_PROP_UINT32("board-rev", BCM2835PropertyState, board_rev, 0),
	DEFINE_PROP_END_OF_LIST()
	};

	static void bcm2835_property_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	device_class_set_props(dc, bcm2835_property_props);
	dc->realize = bcm2835_property_realize;
	dc->vmsd = &vmstate_bcm2835_property;
	}

	static const TypeInfo bcm2835_property_info = {
	.name = TYPE_BCM2835_PROPERTY,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(BCM2835PropertyState),
	.class_init = bcm2835_property_class_init,
	.instance_init = bcm2835_property_init,
	};

	static void bcm2835_property_register_types(void)
	{
	type_register_static(&bcm2835_property_info);
	}

	type_init(bcm2835_property_register_types)