Re: [Qemu-devel] [PATCH v2 2/3] hw/i386/pc: reflect any FDC @ ioport 0x3f0 in the CMOS

[Markus Armbruster <armbru@redhat.com>]

Laszlo Ersek <lersek@redhat.com> writes:

> With the pc-q35-2.4 machine type, if the user creates an ISA FDC manually:
>
>   -device isa-fdc,driveA=drive-fdc0-0-0 \
>   -drive file=...,if=none,id=drive-fdc0-0-0,format=raw
>
> then the board-default FDC will be skipped, and only the explicitly
> requested FDC will exist. qtree-wise, this is correct; however such an FDC
> is currently not registered in the CMOS, because that code is only reached
> for the board-default FDC.
>
> The pc_cmos_init_late() one-shot reset handler -- one-shot because the
> CMOS is not reprogrammed during warm reset -- should search for any ISA
> FDC devices, created implicitly (by board code) or explicitly, and set the
> CMOS accordingly to the ISA FDC(s) with iobase=0x3f0:
>
> - if there is no such FDC, report both drives absent,
> - if there is exactly one such FDC, report its drives in the CMOS,
> - if there are more than one such FDCs, then pick one (it is not specified
>   which one), and print a warning about the ambiguity.
>
> Cc: Jan Tomko <jtomko@redhat.com>
> Cc: John Snow <jsnow@redhat.com>
> Cc: Markus Armbruster <armbru@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Reported-by: Jan Tomko <jtomko@redhat.com>
> Suggested-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> Reviewed-by: John Snow <jsnow@redhat.com>

Reviewed-by: Markus Armbruster <armbru@redhat.com>