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authorMarcin Chojnacki <marcinch7@gmail.com>2017-02-28 12:08:13 +0000
committerPeter Maydell <peter.maydell@linaro.org>2017-02-28 12:08:13 +0000
commit54a5ba13a9ffe7d25fc649b0fa9f8314734c8ccc (patch)
tree969296f64bcd11de22f0971ec334d75ca067c6a5
parent6181478f6395cdd9d6ffd99623d0c9f39ea53606 (diff)
downloadqemu-arm-54a5ba13a9ffe7d25fc649b0fa9f8314734c8ccc.tar.gz
target-arm: Implement BCM2835 hardware RNG
Recent vanilla Raspberry Pi kernels started to make use of the hardware random number generator in BCM2835 SoC. As a result, those kernels wouldn't work anymore under QEMU but rather just freeze during the boot process. This patch implements a trivial BCM2835 compatible RNG, and adds it as a peripheral to BCM2835 platform, which allows to boot a vanilla Raspberry Pi kernel under Qemu. Changes since v1: * Prevented guest from writing [31..20] bits in rng_status * Removed redundant minimum_version_id_old * Added field entries for the state * Changed realize function to reset Signed-off-by: Marcin Chojnacki <marcinch7@gmail.com> Message-id: 20170210210857.47893-1-marcinch7@gmail.com Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--hw/arm/bcm2835_peripherals.c15
-rw-r--r--hw/misc/Makefile.objs1
-rw-r--r--hw/misc/bcm2835_rng.c124
-rw-r--r--include/hw/arm/bcm2835_peripherals.h2
-rw-r--r--include/hw/misc/bcm2835_rng.h27
5 files changed, 169 insertions, 0 deletions
diff --git a/hw/arm/bcm2835_peripherals.c b/hw/arm/bcm2835_peripherals.c
index 2e641a3989..9ed22d5bc8 100644
--- a/hw/arm/bcm2835_peripherals.c
+++ b/hw/arm/bcm2835_peripherals.c
@@ -86,6 +86,11 @@ static void bcm2835_peripherals_init(Object *obj)
object_property_add_const_link(OBJECT(&s->property), "dma-mr",
OBJECT(&s->gpu_bus_mr), &error_abort);
+ /* Random Number Generator */
+ object_initialize(&s->rng, sizeof(s->rng), TYPE_BCM2835_RNG);
+ object_property_add_child(obj, "rng", OBJECT(&s->rng), NULL);
+ qdev_set_parent_bus(DEVICE(&s->rng), sysbus_get_default());
+
/* Extended Mass Media Controller */
object_initialize(&s->sdhci, sizeof(s->sdhci), TYPE_SYSBUS_SDHCI);
object_property_add_child(obj, "sdhci", OBJECT(&s->sdhci), NULL);
@@ -226,6 +231,16 @@ static void bcm2835_peripherals_realize(DeviceState *dev, Error **errp)
sysbus_connect_irq(SYS_BUS_DEVICE(&s->property), 0,
qdev_get_gpio_in(DEVICE(&s->mboxes), MBOX_CHAN_PROPERTY));
+ /* Random Number Generator */
+ object_property_set_bool(OBJECT(&s->rng), true, "realized", &err);
+ if (err) {
+ error_propagate(errp, err);
+ return;
+ }
+
+ memory_region_add_subregion(&s->peri_mr, RNG_OFFSET,
+ sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->rng), 0));
+
/* Extended Mass Media Controller */
object_property_set_int(OBJECT(&s->sdhci), BCM2835_SDHC_CAPAREG, "capareg",
&err);
diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 898e4ccfb1..57a4406581 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -42,6 +42,7 @@ obj-$(CONFIG_OMAP) += omap_sdrc.o
obj-$(CONFIG_OMAP) += omap_tap.o
obj-$(CONFIG_RASPI) += bcm2835_mbox.o
obj-$(CONFIG_RASPI) += bcm2835_property.o
+obj-$(CONFIG_RASPI) += bcm2835_rng.o
obj-$(CONFIG_SLAVIO) += slavio_misc.o
obj-$(CONFIG_ZYNQ) += zynq_slcr.o
obj-$(CONFIG_ZYNQ) += zynq-xadc.o
diff --git a/hw/misc/bcm2835_rng.c b/hw/misc/bcm2835_rng.c
new file mode 100644
index 0000000000..2242bc5eb5
--- /dev/null
+++ b/hw/misc/bcm2835_rng.c
@@ -0,0 +1,124 @@
+/*
+ * BCM2835 Random Number Generator emulation
+ *
+ * Copyright (C) 2017 Marcin Chojnacki <marcinch7@gmail.com>
+ *
+ * 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 "qemu/log.h"
+#include "hw/misc/bcm2835_rng.h"
+
+static uint64_t bcm2835_rng_read(void *opaque, hwaddr offset,
+ unsigned size)
+{
+ BCM2835RngState *s = (BCM2835RngState *)opaque;
+ uint32_t res = 0;
+
+ assert(size == 4);
+
+ switch (offset) {
+ case 0x0: /* rng_ctrl */
+ res = s->rng_ctrl;
+ break;
+ case 0x4: /* rng_status */
+ res = s->rng_status | (1 << 24);
+ break;
+ case 0x8: /* rng_data */
+ res = rand();
+ break;
+
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "bcm2835_rng_read: Bad offset %x\n",
+ (int)offset);
+ res = 0;
+ break;
+ }
+
+ return res;
+}
+
+static void bcm2835_rng_write(void *opaque, hwaddr offset,
+ uint64_t value, unsigned size)
+{
+ BCM2835RngState *s = (BCM2835RngState *)opaque;
+
+ assert(size == 4);
+
+ switch (offset) {
+ case 0x0: /* rng_ctrl */
+ s->rng_ctrl = value;
+ break;
+ case 0x4: /* rng_status */
+ /* we shouldn't let the guest write to bits [31..20] */
+ s->rng_status &= ~0xFFFFF; /* clear 20 lower bits */
+ s->rng_status |= value & 0xFFFFF; /* set them to new value */
+ break;
+
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "bcm2835_rng_write: Bad offset %x\n",
+ (int)offset);
+ break;
+ }
+}
+
+static const MemoryRegionOps bcm2835_rng_ops = {
+ .read = bcm2835_rng_read,
+ .write = bcm2835_rng_write,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const VMStateDescription vmstate_bcm2835_rng = {
+ .name = TYPE_BCM2835_RNG,
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32(rng_ctrl, BCM2835RngState),
+ VMSTATE_UINT32(rng_status, BCM2835RngState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static void bcm2835_rng_init(Object *obj)
+{
+ BCM2835RngState *s = BCM2835_RNG(obj);
+
+ memory_region_init_io(&s->iomem, obj, &bcm2835_rng_ops, s,
+ TYPE_BCM2835_RNG, 0x10);
+ sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
+}
+
+static void bcm2835_rng_reset(DeviceState *dev)
+{
+ BCM2835RngState *s = BCM2835_RNG(dev);
+
+ s->rng_ctrl = 0;
+ s->rng_status = 0;
+}
+
+static void bcm2835_rng_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+
+ dc->reset = bcm2835_rng_reset;
+ dc->vmsd = &vmstate_bcm2835_rng;
+}
+
+static TypeInfo bcm2835_rng_info = {
+ .name = TYPE_BCM2835_RNG,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(BCM2835RngState),
+ .class_init = bcm2835_rng_class_init,
+ .instance_init = bcm2835_rng_init,
+};
+
+static void bcm2835_rng_register_types(void)
+{
+ type_register_static(&bcm2835_rng_info);
+}
+
+type_init(bcm2835_rng_register_types)
diff --git a/include/hw/arm/bcm2835_peripherals.h b/include/hw/arm/bcm2835_peripherals.h
index e12ae3721a..31241c799d 100644
--- a/include/hw/arm/bcm2835_peripherals.h
+++ b/include/hw/arm/bcm2835_peripherals.h
@@ -19,6 +19,7 @@
#include "hw/dma/bcm2835_dma.h"
#include "hw/intc/bcm2835_ic.h"
#include "hw/misc/bcm2835_property.h"
+#include "hw/misc/bcm2835_rng.h"
#include "hw/misc/bcm2835_mbox.h"
#include "hw/sd/sdhci.h"
@@ -41,6 +42,7 @@ typedef struct BCM2835PeripheralState {
BCM2835DMAState dma;
BCM2835ICState ic;
BCM2835PropertyState property;
+ BCM2835RngState rng;
BCM2835MboxState mboxes;
SDHCIState sdhci;
} BCM2835PeripheralState;
diff --git a/include/hw/misc/bcm2835_rng.h b/include/hw/misc/bcm2835_rng.h
new file mode 100644
index 0000000000..41a531bce7
--- /dev/null
+++ b/include/hw/misc/bcm2835_rng.h
@@ -0,0 +1,27 @@
+/*
+ * BCM2835 Random Number Generator emulation
+ *
+ * Copyright (C) 2017 Marcin Chojnacki <marcinch7@gmail.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef BCM2835_RNG_H
+#define BCM2835_RNG_H
+
+#include "hw/sysbus.h"
+
+#define TYPE_BCM2835_RNG "bcm2835-rng"
+#define BCM2835_RNG(obj) \
+ OBJECT_CHECK(BCM2835RngState, (obj), TYPE_BCM2835_RNG)
+
+typedef struct {
+ SysBusDevice busdev;
+ MemoryRegion iomem;
+
+ uint32_t rng_ctrl;
+ uint32_t rng_status;
+} BCM2835RngState;
+
+#endif