Am 3. März 2026 22:56:20 UTC schrieb BALATON Zoltan <[email protected]>:
>On Tue, 3 Mar 2026, Bernhard Beschow wrote:
>> Rather than requiring users of TYPE_SERIAL to initialize the MMIO region
>> themselves, make it generic enough to be configured via properties. This
>> makes TYPE_SERIAL more self-contained and prepares it for being turned
>> into a SysBusDevice.
>>
>> Signed-off-by: Bernhard Beschow <[email protected]>
>> ---
>> include/hw/char/serial-mm.h | 3 --
>> include/hw/char/serial.h | 4 +-
>> hw/char/diva-gsp.c | 5 ---
>> hw/char/serial-isa.c | 1 -
>> hw/char/serial-mm.c | 51 -------------------------
>> hw/char/serial-pci-multi.c | 5 ---
>> hw/char/serial-pci.c | 1 -
>> hw/char/serial.c | 76 ++++++++++++++++++++++++++++++-------
>> 8 files changed, 66 insertions(+), 80 deletions(-)
>>
>> diff --git a/include/hw/char/serial-mm.h b/include/hw/char/serial-mm.h
>> index 0076bdc061..4c18e2a609 100644
>> --- a/include/hw/char/serial-mm.h
>> +++ b/include/hw/char/serial-mm.h
>> @@ -39,9 +39,6 @@ struct SerialMM {
>> SysBusDevice parent;
>>
>> SerialState serial;
>> -
>> - uint8_t regshift;
>> - uint8_t endianness;
>> };
>
>This effectively makes TYPE_SERIAL the same as TYPE_SERIAL_MM so you could
>just merge the two and have everything embed a SERIAL_MM device.
I've tried having TYPE_SERIAL_MM inherit from the SysBus-TYPE_SERIAL. This
resulted in failing migration tests, so I stayed with composition.
> But the idea here is to make TYPE_SERIAL a superclass of all serial devices
> and SERIAL_MM is the memory mapped version. Memory mapped devices are usually
> SysBusDevices but others are not so this seems to be trying to model things
> in the wrong way. Maybe you could just add accessor functions to TYPE_SERIAL
> to get the memory regions and use that from subclasses to avoid poking in the
> state struct and not try to reuse SysBusDevice for this.
After ruling out inheritance, adding just accessor methods would basically
reinvent SysBusDevice without the benefit of the reset tree.
My goal is to rewrite TYPE_SERIAL in Rust which requires it to be accessed only
via methods. Not Plugging into the reset tree would be an inconvenience I'd
like to avoid. The rewritten version already works except for migration. I
didn't "advertise" this too much in the cover letter since these changes should
be useful on their own.
Best regards,
Bernhard
>
>Regards,
>BALATON Zoltan
