On Thu, Sep 08, 2022 at 02:11:28PM +0400, Marc-André Lureau wrote: > Hi > > On Wed, Sep 7, 2022 at 2:03 AM Arwed Meyer <arwed.me...@gmx.de> wrote: > > Unaligned i/o access on serial UART works on real PCs. > This is used for example by FreeDOS CTMouse driver. Without this it > can't reset and detect serial mice. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/77 > Signed-off-by: Arwed Meyer <arwed.me...@gmx.de> > --- > hw/char/serial.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/hw/char/serial.c b/hw/char/serial.c > index 7061aacbce..41b5e61977 100644 > --- a/hw/char/serial.c > +++ b/hw/char/serial.c > @@ -961,6 +961,9 @@ void serial_set_frequency(SerialState *s, uint32_t > frequency) > const MemoryRegionOps serial_io_ops = { > .read = serial_ioport_read, > .write = serial_ioport_write, > + .valid = { > + .unaligned = 1, > + }, > > > I don't get how this can help if both min_access_size & max_access_size are 1. > > > .impl = { > .min_access_size = 1, > .max_access_size = 1, > -- > 2.34.1
Because that's .impl. If access is invalid we don't get as far as breaking it up to chunks. > > > > > -- > Marc-André Lureau