[Qemu-devel] Re: sparc esp dma endianness [patch-rfc]

[Blue Swirl <blauwirbel@gmail.com>]

On Tue, Sep 1, 2009 at 8:08 PM, Artyom
Tarasenko<atar4qemu@googlemail.com> wrote:
> 2009/9/1 Blue Swirl <blauwirbel@gmail.com>:
>> Usually the first byte is bus id. What if you changed (as a hack) here:
>>    DPRINTF("do_cmd: busid 0x%x\n", buf[0]);
>>    lun = buf[0] & 7;
>>    datalen = s->current_dev->send_command(s->current_dev, 0, &buf[1], lun);
>> &buf[1] to &buf[0]?
>
> Yep, figured that out too, but did a little more complex hack:
>
> lun = buf[1] >>5;
> datalen = s->current_dev->send_command(s->current_dev, 0, &buf[0], lun);
>
> with this hack OBP checks proper LUNs.
>
> So, the problem is not endianness, but the missing bus id. But how the
> bus id should get into the dma buffer?
> It should be generated by esp, right?
>

It could be pushed into FIFO with PIO.