On 2/8/23 11:48, Mark Cave-Ayland wrote:
The ESP FIFO is used as a buffer for DMA requests and so isn't guaranteed to
be empty in the case of SCSI errors or a mixed DMA/non-DMA request. Flush the
FIFO before sending a SCSI command to guarantee that it is correctly
positioned at the start of the
On 29/7/23 15:04, Mark Cave-Ayland wrote:
The ESP FIFO is used as a buffer for DMA requests and so isn't guaranteed to
be empty in the case of SCSI errors or a mixed DMA/non-DMA request. Flush the
FIFO before sending a SCSI command to guarantee that it is correctly
positioned at the start of the
The ESP SELATN command used to send SCSI commands from the ESP to the SCSI bus
is not a DMA command and therefore does not affect the STAT_TC bit. The only
reason this works at all is due to a bug in QEMU which (currently) always
updates the STAT_TC bit in ESP_RSTAT regardless of the state of the
The ESP FIFO is used as a buffer for DMA requests and so isn't guaranteed to
be empty in the case of SCSI errors or a mixed DMA/non-DMA request. Flush the
FIFO before sending a SCSI command to guarantee that it is correctly
positioned at the start of the FIFO.
Signed-off-by: Mark Cave-Ayland
---
Whilst trying to improve QEMU's ESP SCSI implementation with regard to the
NCR datasheet, I noticed that SeaBIOS would fail to boot one of my Debian
test images with my patches applied.
Further investigation revealed that the SeaBIOS esp-scsi driver inadvertently
relies on existing bugs in QEMU's
On 01/08/2023 03:07, Paul Menzel wrote:
Dear Mark,
Am 30.07.23 um 10:56 schrieb Mark Cave-Ayland:
On 30/07/2023 08:47, Paul Menzel wrote:
[Cc: +Paolo as original author of the driver]
[…]
Am 29.07.23 um 15:04 schrieb Mark Cave-Ayland:
The ESP SELATN command used to send SCSI commands
