Re: [Qemu-devel] [PATCH] boards: add a 'none' machine type to all platforms

[Anthony Liguori <aliguori@us.ibm.com>]

Peter Maydell <peter.maydell@linaro.org> writes:

> On 22 August 2012 21:24, Anthony Liguori <aliguori@us.ibm.com> wrote:
>> This allows any QEMU binary to be executed with:
>>
>>   $QEMU_BINARY -qmp stdio
>
> ...presumably you mean -qmp stdio -M none ?
>
>>
>> Without errors from missing options that are required by various boards.  This
>> also provides a mode that we can use in the future to construct machines
>> entirely through QMP commands.
>
> How about documenting this machine (and its purpose) somewhere?

Okay, but where?  I don't know an obvious place.

>> Cc: Daniel Berrange <berrange@redhat.com>
>> Cc: Markus Armbruster <armbru@redhat.com>
>> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
>> ---
>>  hw/Makefile.objs  |    2 ++
>>  hw/null-machine.c |   40 ++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 42 insertions(+), 0 deletions(-)
>>  create mode 100644 hw/null-machine.c
>>
>> diff --git a/hw/Makefile.objs b/hw/Makefile.objs
>> index 7f57ed5..6dfebd2 100644
>> --- a/hw/Makefile.objs
>> +++ b/hw/Makefile.objs
>> @@ -134,6 +134,8 @@ hw-obj-$(CONFIG_DP8393X) += dp8393x.o
>>  hw-obj-$(CONFIG_DS1225Y) += ds1225y.o
>>  hw-obj-$(CONFIG_MIPSNET) += mipsnet.o
>>
>> +hw-obj-y += null-machine.o
>> +
>>  # Sound
>>  sound-obj-y =
>>  sound-obj-$(CONFIG_SB16) += sb16.o
>> diff --git a/hw/null-machine.c b/hw/null-machine.c
>> new file mode 100644
>> index 0000000..69910d3
>> --- /dev/null
>> +++ b/hw/null-machine.c
>> @@ -0,0 +1,40 @@
>> +/*
>> + * Empty machine
>> + *
>> + * Copyright IBM, Corp. 2012
>> + *
>> + * Authors:
>> + *  Anthony Liguori   <aliguori@us.ibm.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-common.h"
>> +#include "hw/hw.h"
>> +#include "hw/boards.h"
>> +
>> +static void machine_none_init(ram_addr_t ram_size,
>> +                              const char *boot_device,
>> +                              const char *kernel_filename,
>> +                              const char *kernel_cmdline,
>> +                              const char *initrd_filename,
>> +                              const char *cpu_model)
>> +{
>> +}
>> +
>> +static QEMUMachine machine_none = {
>> +    .name = "none",
>> +    .desc = "empty machine",
>> +    .init = machine_none_init,
>> +    .max_cpus = 0,
>> +};
>> +
>> +static void register_machines(void)
>> +{
>> +    qemu_register_machine(&machine_none);
>> +}
>> +
>> +machine_init(register_machines);
>
> We seem to be about evenly split about whether machine_init()
> should have a trailing semicolon (it doesn't need one
> but it doesn't hurt either...)

It's obviously superior to use a semicolon...  C is completely
consistent synactically about the usage of semicolons afterall :-)

Regards,

Anthony Liguori

>
> -- PMM