[Qemu-devel] [PATCH v4 0/3] arm: Add nRF51 SoC and micro:bit machine

[Qemu-devel] [PATCH v4 0/3] arm: Add nRF51 SoC and micro:bit machine

[Joel Stanley]

v4: Fix number of IRQs
Based-on: 20180725085944.11856-1-stefanha@redhat.com

This short series implements a minimal definition of the Nordic
Semiconductor nRF51, a Cortex-M0 ARM SoC, and the BBC micro:bit, a
machine that will use this SoC.

This work will serve as the base for our Google Summer of Code and
Outreachy interns who will work on implementing a number of features on
top of this base.

I've tested this with a microbit micropython firmware, and checked that
it starts running by looking at it with gdb.

I chose to keep the nrf51 and the microbit seperate, to not confuse the
peripherals that are on the microbit but are not part of the nrf51, and
vice versa.

Joel Stanley (3):
  MAINTAINERS: Add NRF51 entry
  arm: Add Nordic Semiconductor nRF51 SoC
  arm: Add BBC micro:bit machine

 MAINTAINERS                     |   8 +++
 default-configs/arm-softmmu.mak |   1 +
 hw/arm/Makefile.objs            |   1 +
 hw/arm/microbit.c               |  54 +++++++++++++++
 hw/arm/nrf51_soc.c              | 119 ++++++++++++++++++++++++++++++++
 include/hw/arm/nrf51_soc.h      |  42 +++++++++++
 6 files changed, 225 insertions(+)
 create mode 100644 hw/arm/microbit.c
 create mode 100644 hw/arm/nrf51_soc.c
 create mode 100644 include/hw/arm/nrf51_soc.h

-- 
2.17.1

[Qemu-devel] [PATCH v4 1/3] MAINTAINERS: Add NRF51 entry

[Joel Stanley]

This contains the NRF51, and the machine that uses it, the BBC
micro:bit.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v3:
  fix spelling of mailing list
  add stefan's reviewed-by
---
 MAINTAINERS | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index c48d9271cf15..5a0d2e327d4a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -656,6 +656,14 @@ F: include/hw/*/*aspeed*
 F: hw/net/ftgmac100.c
 F: include/hw/net/ftgmac100.h
 
+NRF51
+M: Joel Stanley <joel@jms.id.au>
+L: qemu-arm@nongnu.org
+S: Maintained
+F: hw/arm/nrf51_soc.c
+F: hw/arm/microbit.c
+F: include/hw/arm/nrf51_soc.h
+
 CRIS Machines
 -------------
 Axis Dev88
-- 
2.17.1

[Qemu-devel] [PATCH v4 2/3] arm: Add Nordic Semiconductor nRF51 SoC

[Joel Stanley]

The nRF51 is a Cortex-M0 microcontroller with an on-board radio module,
plus other common ARM SoC peripherals.

 http://infocenter.nordicsemi.com/pdf/nRF51_RM_v3.0.pdf

This defines a basic model of the CPU and memory, with no peripherals
implemented at this stage.

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v2:
  put memory as struct fileds in state structure
  pass OBJECT(s) as owner, not NULL
  Add missing addresses for ficr
  Fix flash and sram sizes for microbit
  Embed cpu object in state object an initalise it without use of armv7m_init
  Link to datasheet
v3:
  rebase nrf51 on m0 changes
  remove unused kernel_filename
  clarify flash and sram size
  make flash and sram size properties of the soc state
v4:
  set the number of interrupts to 32
---
 default-configs/arm-softmmu.mak |   1 +
 hw/arm/Makefile.objs            |   1 +
 hw/arm/nrf51_soc.c              | 119 ++++++++++++++++++++++++++++++++
 include/hw/arm/nrf51_soc.h      |  42 +++++++++++
 4 files changed, 163 insertions(+)
 create mode 100644 hw/arm/nrf51_soc.c
 create mode 100644 include/hw/arm/nrf51_soc.h

diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
index e704cb6e34d7..3432721d7d08 100644
--- a/default-configs/arm-softmmu.mak
+++ b/default-configs/arm-softmmu.mak
@@ -102,6 +102,7 @@ CONFIG_STM32F2XX_SYSCFG=y
 CONFIG_STM32F2XX_ADC=y
 CONFIG_STM32F2XX_SPI=y
 CONFIG_STM32F205_SOC=y
+CONFIG_NRF51_SOC=y
 
 CONFIG_CMSDK_APB_TIMER=y
 CONFIG_CMSDK_APB_UART=y
diff --git a/hw/arm/Makefile.objs b/hw/arm/Makefile.objs
index b1e4f8f006aa..e31875ec69bc 100644
--- a/hw/arm/Makefile.objs
+++ b/hw/arm/Makefile.objs
@@ -36,3 +36,4 @@ obj-$(CONFIG_MSF2) += msf2-soc.o msf2-som.o
 obj-$(CONFIG_IOTKIT) += iotkit.o
 obj-$(CONFIG_FSL_IMX7) += fsl-imx7.o mcimx7d-sabre.o
 obj-$(CONFIG_ARM_SMMUV3) += smmu-common.o smmuv3.o
+obj-$(CONFIG_NRF51_SOC) += nrf51_soc.o
diff --git a/hw/arm/nrf51_soc.c b/hw/arm/nrf51_soc.c
new file mode 100644
index 000000000000..27b57e64735c
--- /dev/null
+++ b/hw/arm/nrf51_soc.c
@@ -0,0 +1,119 @@
+/*
+ * Nordic Semiconductor nRF51 SoC
+ * http://infocenter.nordicsemi.com/pdf/nRF51_RM_v3.0.1.pdf
+ *
+ * Copyright 2018 Joel Stanley <joel@jms.id.au>
+ *
+ * This code is licensed under the GPL version 2 or later.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu-common.h"
+#include "hw/arm/arm.h"
+#include "hw/sysbus.h"
+#include "hw/boards.h"
+#include "hw/devices.h"
+#include "hw/misc/unimp.h"
+#include "exec/address-spaces.h"
+#include "sysemu/sysemu.h"
+#include "qemu/log.h"
+#include "cpu.h"
+
+#include "hw/arm/nrf51_soc.h"
+
+#define IOMEM_BASE      0x40000000
+#define IOMEM_SIZE      0x20000000
+
+#define FICR_BASE       0x10000000
+#define FICR_SIZE       0x000000fc
+
+#define FLASH_BASE      0x00000000
+#define SRAM_BASE       0x20000000
+
+/* The size and base is for the NRF51822 part. If other parts
+ * are supported in the future, add a sub-class of NRF51SoC for
+ * the specific variants */
+#define NRF51822_FLASH_SIZE     (256 * 1024)
+#define NRF51822_SRAM_SIZE      (16 * 1024)
+
+static void nrf51_soc_realize(DeviceState *dev_soc, Error **errp)
+{
+    NRF51State *s = NRF51_SOC(dev_soc);
+    Error *err = NULL;
+
+    if (!s->board_memory) {
+        error_setg(errp, "memory property was not set");
+        return;
+    }
+
+    object_property_set_link(OBJECT(&s->cpu), OBJECT(&s->container), "memory",
+            &err);
+    object_property_set_bool(OBJECT(&s->cpu), true, "realized", &err);
+
+    memory_region_add_subregion_overlap(&s->container, 0, s->board_memory, -1);
+
+    memory_region_init_ram(&s->flash, OBJECT(s), "nrf51.flash", s->flash_size,
+            &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+    memory_region_set_readonly(&s->flash, true);
+    memory_region_add_subregion(&s->container, FLASH_BASE, &s->flash);
+
+    memory_region_init_ram(&s->sram, NULL, "nrf51.sram", s->sram_size, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+    memory_region_add_subregion(&s->container, SRAM_BASE, &s->sram);
+
+    create_unimplemented_device("nrf51_soc.io", IOMEM_BASE, IOMEM_SIZE);
+    create_unimplemented_device("nrf51_soc.ficr", FICR_BASE, FICR_SIZE);
+    create_unimplemented_device("nrf51_soc.private", 0xF0000000, 0x10000000);
+}
+
+static void nrf51_soc_init(Object *obj)
+{
+    NRF51State *s = NRF51_SOC(obj);
+
+    memory_region_init(&s->container, obj, "nrf51-container", UINT64_MAX);
+
+    object_initialize(&s->cpu, sizeof(s->cpu), TYPE_ARM_M_PROFILE);
+    object_property_add_child(OBJECT(s), "armv6m", OBJECT(&s->cpu), &error_abort);
+    qdev_set_parent_bus(DEVICE(&s->cpu), sysbus_get_default());
+    qdev_prop_set_string(DEVICE(&s->cpu), "cpu-type", ARM_CPU_TYPE_NAME("cortex-m0"));
+    qdev_prop_set_uint32(DEVICE(&s->cpu), "num-irq", 32);
+}
+
+static Property nrf51_soc_properties[] = {
+    DEFINE_PROP_LINK("memory", NRF51State, board_memory, TYPE_MEMORY_REGION,
+                     MemoryRegion *),
+    DEFINE_PROP_UINT32("sram-size", NRF51State, sram_size, NRF51822_SRAM_SIZE),
+    DEFINE_PROP_UINT32("flash-size", NRF51State, flash_size, NRF51822_FLASH_SIZE),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void nrf51_soc_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = nrf51_soc_realize;
+    dc->props = nrf51_soc_properties;
+}
+
+static const TypeInfo nrf51_soc_info = {
+    .name          = TYPE_NRF51_SOC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(NRF51State),
+    .instance_init = nrf51_soc_init,
+    .class_init    = nrf51_soc_class_init,
+};
+
+static void nrf51_soc_types(void)
+{
+    type_register_static(&nrf51_soc_info);
+}
+type_init(nrf51_soc_types)
diff --git a/include/hw/arm/nrf51_soc.h b/include/hw/arm/nrf51_soc.h
new file mode 100644
index 000000000000..838bccd815df
--- /dev/null
+++ b/include/hw/arm/nrf51_soc.h
@@ -0,0 +1,42 @@
+/*
+ * Nordic Semiconductor nRF51  SoC
+ *
+ * Copyright 2018 Joel Stanley <joel@jms.id.au>
+ *
+ * This code is licensed under the GPL version 2 or later.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#ifndef NRF51_SOC_H
+#define NRF51_SOC_H
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "hw/arm/arm-m-profile.h"
+
+#define TYPE_NRF51_SOC "nrf51-soc"
+#define NRF51_SOC(obj) \
+    OBJECT_CHECK(NRF51State, (obj), TYPE_NRF51_SOC)
+
+typedef struct NRF51State {
+    /*< private >*/
+    SysBusDevice parent_obj;
+
+    /*< public >*/
+    ARMMProfileState cpu;
+
+    MemoryRegion iomem;
+    MemoryRegion sram;
+    MemoryRegion flash;
+
+    uint32_t sram_size;
+    uint32_t flash_size;
+
+    MemoryRegion *board_memory;
+
+    MemoryRegion container;
+
+} NRF51State;
+
+#endif
+
-- 
2.17.1

[Qemu-devel] [PATCH v4 3/3] arm: Add BBC micro:bit machine

[Joel Stanley]

This adds the base for a machine model of the BBC micro:bit:

  https://en.wikipedia.org/wiki/Micro_Bit

This is a system with a nRF51 SoC containing the main processor, with
various peripherals on board.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v2:
 - Instead of setting kernel filename property, load the image directly
 - Add link to hardware overview website
v3:
 - Rebase microbit on m0 changes
 - Remove hard-coded flash size and retrieve from the soc
 - Add Stefan's reviewed-by
---
 hw/arm/Makefile.objs |  2 +-
 hw/arm/microbit.c    | 54 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 hw/arm/microbit.c

diff --git a/hw/arm/Makefile.objs b/hw/arm/Makefile.objs
index e31875ec69bc..2798a257921d 100644
--- a/hw/arm/Makefile.objs
+++ b/hw/arm/Makefile.objs
@@ -36,4 +36,4 @@ obj-$(CONFIG_MSF2) += msf2-soc.o msf2-som.o
 obj-$(CONFIG_IOTKIT) += iotkit.o
 obj-$(CONFIG_FSL_IMX7) += fsl-imx7.o mcimx7d-sabre.o
 obj-$(CONFIG_ARM_SMMUV3) += smmu-common.o smmuv3.o
-obj-$(CONFIG_NRF51_SOC) += nrf51_soc.o
+obj-$(CONFIG_NRF51_SOC) += nrf51_soc.o microbit.o
diff --git a/hw/arm/microbit.c b/hw/arm/microbit.c
new file mode 100644
index 000000000000..ecf64e883f4f
--- /dev/null
+++ b/hw/arm/microbit.c
@@ -0,0 +1,54 @@
+/*
+ * BBC micro:bit machine
+ * http://tech.microbit.org/hardware/
+ *
+ * Copyright 2018 Joel Stanley <joel@jms.id.au>
+ *
+ * This code is licensed under the GPL version 2 or later.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/boards.h"
+#include "hw/arm/arm.h"
+#include "exec/address-spaces.h"
+
+#include "hw/arm/nrf51_soc.h"
+
+typedef struct {
+    MachineState parent;
+
+    NRF51State nrf51;
+} MICROBITMachineState;
+
+#define TYPE_MICROBIT_MACHINE "microbit"
+
+#define MICROBIT_MACHINE(obj) \
+    OBJECT_CHECK(MICROBITMachineState, obj, TYPE_MICROBIT_MACHINE)
+
+static void microbit_init(MachineState *machine)
+{
+    MICROBITMachineState *s = g_new(MICROBITMachineState, 1);
+    MemoryRegion *system_memory = get_system_memory();
+    Object *soc;
+
+    object_initialize(&s->nrf51, sizeof(s->nrf51), TYPE_NRF51_SOC);
+    soc = OBJECT(&s->nrf51);
+    object_property_add_child(OBJECT(machine), "nrf51", soc, &error_fatal);
+    object_property_set_link(soc, OBJECT(system_memory),
+                             "memory", &error_abort);
+
+    object_property_set_bool(soc, true, "realized", &error_abort);
+
+    arm_m_profile_load_kernel(ARM_CPU(first_cpu), machine->kernel_filename,
+            NRF51_SOC(soc)->flash_size);
+}
+
+static void microbit_machine_init(MachineClass *mc)
+{
+    mc->desc = "BBC micro:bit";
+    mc->init = microbit_init;
+    mc->max_cpus = 1;
+}
+DEFINE_MACHINE("microbit", microbit_machine_init);
-- 
2.17.1

Re: [Qemu-devel] [PATCH v4 3/3] arm: Add BBC micro:bit machine

[Peter Maydell]

On 3 August 2018 at 06:21, Joel Stanley <joel@jms.id.au> wrote:
> This adds the base for a machine model of the BBC micro:bit:
>
>   https://en.wikipedia.org/wiki/Micro_Bit
>
> This is a system with a nRF51 SoC containing the main processor, with
> various peripherals on board.
>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> ---
> v2:
>  - Instead of setting kernel filename property, load the image directly
>  - Add link to hardware overview website
> v3:
>  - Rebase microbit on m0 changes
>  - Remove hard-coded flash size and retrieve from the soc
>  - Add Stefan's reviewed-by
> ---
>  hw/arm/Makefile.objs |  2 +-
>  hw/arm/microbit.c    | 54 ++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 55 insertions(+), 1 deletion(-)
>  create mode 100644 hw/arm/microbit.c
>
> diff --git a/hw/arm/Makefile.objs b/hw/arm/Makefile.objs
> index e31875ec69bc..2798a257921d 100644
> --- a/hw/arm/Makefile.objs
> +++ b/hw/arm/Makefile.objs
> @@ -36,4 +36,4 @@ obj-$(CONFIG_MSF2) += msf2-soc.o msf2-som.o
>  obj-$(CONFIG_IOTKIT) += iotkit.o
>  obj-$(CONFIG_FSL_IMX7) += fsl-imx7.o mcimx7d-sabre.o
>  obj-$(CONFIG_ARM_SMMUV3) += smmu-common.o smmuv3.o
> -obj-$(CONFIG_NRF51_SOC) += nrf51_soc.o
> +obj-$(CONFIG_NRF51_SOC) += nrf51_soc.o microbit.o
> diff --git a/hw/arm/microbit.c b/hw/arm/microbit.c
> new file mode 100644
> index 000000000000..ecf64e883f4f
> --- /dev/null
> +++ b/hw/arm/microbit.c
> @@ -0,0 +1,54 @@
> +/*
> + * BBC micro:bit machine
> + * http://tech.microbit.org/hardware/
> + *
> + * Copyright 2018 Joel Stanley <joel@jms.id.au>
> + *
> + * This code is licensed under the GPL version 2 or later.  See
> + * the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qapi/error.h"
> +#include "hw/boards.h"
> +#include "hw/arm/arm.h"
> +#include "exec/address-spaces.h"
> +
> +#include "hw/arm/nrf51_soc.h"
> +
> +typedef struct {
> +    MachineState parent;
> +
> +    NRF51State nrf51;
> +} MICROBITMachineState;

Can we call this "MicrobitMachineState", please? I don't
think the board name is all-caps, and our convention
for struct type names is CamelCase.

> +
> +#define TYPE_MICROBIT_MACHINE "microbit"

Should be MACHINE_TYPE_NAME("microbit")

> +
> +#define MICROBIT_MACHINE(obj) \
> +    OBJECT_CHECK(MICROBITMachineState, obj, TYPE_MICROBIT_MACHINE)
> +
> +static void microbit_init(MachineState *machine)
> +{
> +    MICROBITMachineState *s = g_new(MICROBITMachineState, 1);

This is odd. The MICROBITMachineState is the state struct
for your subclass of MachineState, and that object has
already been allocated (you get a pointer to it as the
argument to the init function here). So all you need to do
is cast it to the right type:
      MICROBITMachineState *s = MICROBIT_MACHINE(machine);

You don't need to allocate a second copy. (You do need to
get the type registration right so that you declare that the
type is of size sizeof(MICROBITMachineState) rather than
just sizeof(MachineState), though -- see below.)

> +    MemoryRegion *system_memory = get_system_memory();
> +    Object *soc;
> +
> +    object_initialize(&s->nrf51, sizeof(s->nrf51), TYPE_NRF51_SOC);
> +    soc = OBJECT(&s->nrf51);
> +    object_property_add_child(OBJECT(machine), "nrf51", soc, &error_fatal);

You should use the new function init_sysbus_child() here
rather than doing separate initialize and add_child steps
(we realised late in the 3.0 cycle that we had refcount
leaks as a result of doing this as a 2-step process, hence
the new function).

> +    object_property_set_link(soc, OBJECT(system_memory),
> +                             "memory", &error_abort);
> +
> +    object_property_set_bool(soc, true, "realized", &error_abort);

Better to use error_fatal rather than error_abort in these two calls,
I think.

> +
> +    arm_m_profile_load_kernel(ARM_CPU(first_cpu), machine->kernel_filename,
> +            NRF51_SOC(soc)->flash_size);
> +}
> +
> +static void microbit_machine_init(MachineClass *mc)
> +{
> +    mc->desc = "BBC micro:bit";
> +    mc->init = microbit_init;
> +    mc->max_cpus = 1;
> +}
> +DEFINE_MACHINE("microbit", microbit_machine_init);

Your subclass of TYPE_MACHINE has extra state, so it can't
use DEFINE_MACHINE (which creates a subclass whose instance_size
is the same as the parent TYPE_MACHINE). You need to do this
longhand:

static void machine_class_init(ObjectClass *oc, void *data)
{
    MachineClass *mc = MACHINE_CLASS(oc);

    mc->desc = "BBC micro:bit";
    mc->init = microbit_init;
    mc->max_cpus = 1;
}

static const TypeInfo microbit_info = {
    .name = TYPE_MICROBIT_MACHINE,
    .parent = TYPE_MACHINE,
    .instance_size = sizeof(MICROBITMachineState),
    .class_init = microbit_class_init,
};

static void microbit_machine_init(void)
{
    type_register_static(&microbit_info);
}

type_init(microbit_machine_init);


(code untested but should be correct; compare against other boards.)

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 1/3] MAINTAINERS: Add NRF51 entry

[Peter Maydell]

On 3 August 2018 at 06:21, Joel Stanley <joel@jms.id.au> wrote:
> This contains the NRF51, and the machine that uses it, the BBC
> micro:bit.
>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> ---
> v3:
>   fix spelling of mailing list
>   add stefan's reviewed-by
> ---
>  MAINTAINERS | 8 ++++++++
>  1 file changed, 8 insertions(+)

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 3/3] arm: Add BBC micro:bit machine

[Steffen Görtz]

>> +
>> +    arm_m_profile_load_kernel(ARM_CPU(first_cpu), machine->kernel_filename,
>> +            NRF51_SOC(soc)->flash_size);
>> +}
>> +
>> +static void microbit_machine_init(MachineClass *mc)
>> +{
>> +    mc->desc = "BBC micro:bit";
>> +    mc->init = microbit_init;
>> +    mc->max_cpus = 1;
>> +}
>> +DEFINE_MACHINE("microbit", microbit_machine_init);
> 
> Your subclass of TYPE_MACHINE has extra state, so it can't
> use DEFINE_MACHINE (which creates a subclass whose instance_size
> is the same as the parent TYPE_MACHINE). You need to do this
> longhand:
> 

Hi Peter,

this is covered in <20180811090836.4024-1-contrib@steffen-goertz.de>

Steffen

Re: [Qemu-devel] [PATCH v4 3/3] arm: Add BBC micro:bit machine

[Peter Maydell]

On 16 August 2018 at 15:19, Steffen Görtz <mail@steffen-goertz.de> wrote:
>
>>> +
>>> +    arm_m_profile_load_kernel(ARM_CPU(first_cpu), machine->kernel_filename,
>>> +            NRF51_SOC(soc)->flash_size);
>>> +}
>>> +
>>> +static void microbit_machine_init(MachineClass *mc)
>>> +{
>>> +    mc->desc = "BBC micro:bit";
>>> +    mc->init = microbit_init;
>>> +    mc->max_cpus = 1;
>>> +}
>>> +DEFINE_MACHINE("microbit", microbit_machine_init);
>>
>> Your subclass of TYPE_MACHINE has extra state, so it can't
>> use DEFINE_MACHINE (which creates a subclass whose instance_size
>> is the same as the parent TYPE_MACHINE). You need to do this
>> longhand:
>>
>
> Hi Peter,
>
> this is covered in <20180811090836.4024-1-contrib@steffen-goertz.de>

So it is. This patch is wrong though, so the fix needs to be
made by folding the relevant changes into this patch, not as
a separate commit later.

PS: you don't really need a header file for the machine's
struct, because nothing except the machine's .c file will
ever need to include it.

thanks
-- PMM

Re: [Qemu-devel] [PATCH v4 3/3] arm: Add BBC micro:bit machine

[Joel Stanley]

On Thu, 16 Aug 2018 at 07:12, Peter Maydell <peter.maydell@linaro.org> wrote:

> > +static void microbit_machine_init(MachineClass *mc)
> > +{
> > +    mc->desc = "BBC micro:bit";
> > +    mc->init = microbit_init;
> > +    mc->max_cpus = 1;
> > +}
> > +DEFINE_MACHINE("microbit", microbit_machine_init);
>
> Your subclass of TYPE_MACHINE has extra state, so it can't
> use DEFINE_MACHINE (which creates a subclass whose instance_size
> is the same as the parent TYPE_MACHINE). You need to do this
> longhand:
>
> static void machine_class_init(ObjectClass *oc, void *data)
> {
>     MachineClass *mc = MACHINE_CLASS(oc);
>
>     mc->desc = "BBC micro:bit";
>     mc->init = microbit_init;
>     mc->max_cpus = 1;
> }
>
> static const TypeInfo microbit_info = {
>     .name = TYPE_MICROBIT_MACHINE,
>     .parent = TYPE_MACHINE,
>     .instance_size = sizeof(MICROBITMachineState),
>     .class_init = microbit_class_init,
> };
>
> static void microbit_machine_init(void)
> {
>     type_register_static(&microbit_info);
> }
>
> type_init(microbit_machine_init);
>
>
> (code untested but should be correct; compare against other boards.)

Thanks for spelling it out. I spent a decent chunk of time looking at
other boards, and this aspect of Qemu still baffles me.