[SeaBIOS] Re: [PATCH] esp-scsi: terminate DMA transfer when ESP data transfer completes

[Gerd Hoffmann]

On Mon, Jan 01, 2024 at 12:19:42PM +0000, Mark Cave-Ayland wrote:
> When the ESP data transfer completes indicated by the STAT_TC flag being set,
> terminate the DMA transfer by issuing a DMA IDLE command. Otherwise in the case
> where the guest sends a reset followed by an ESP command, the DMA signal remains
> enabled and so the next SeaBIOS DMA transfer begins immediately when the next
> ESP command is received rather than waiting until the data is ready and the DMA
> command is issued.
>
> With this fix it is possible to boot a Windows XP ISO to the installer and
> complete a full installation within QEMU directly using SeaBIOS.
> Signed-off-by: Mark Cave-Ayland
>
> src/hw/esp-scsi.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> [This fixes the Windows XP setup issue reported by Paolo when DC390 support was
> first added to QEMU (see https://lore.kernel.org/all/[e-mail]/
> for the original thread) way back in 2012.]
>
> diff --git a/src/hw/esp-scsi.c b/src/hw/esp-scsi.c
> index f19804f..8612069 100644
> --- a/src/hw/esp-scsi.c
> +++ b/src/hw/esp-scsi.c
> @@ -147,6 +147,8 @@ esp_scsi_process_op(struct disk_op_s *op)
>          /* At end of DMA TC is set again -> complete command.  */
>          if (state == 1 && (stat & ESP_STAT_TC)) {
>              state++;
>        /* Terminate esp_scsi_dma() command */
>        outb(0, iobase + ESP_DMA_CMD);
>        continue;
>    }

Patch applied to master branch.

thanks,
  Gerd