Re: [Qemu-devel] LSI53C895A, IDE HDD detection under SCO OpenServer 5.0.5

[andrzej zaborowski]

Hi,

2008/11/4 Justin Chevrier <address@hidden>:
> Well I've made some progress with getting the LSI53C895A emulated card 
> working under Openserver. After going through the debug log and scratching my 
> head for quite some time. I found the following:
>
> The problem was with this block move:
>
> lsi_scsi: SCRIPTS dsp=0fae8e50 opcode 01000028 arg 00f63c40
> lsi_scsi: DMA addr=0x00f63c40 len=36
>
> The number of bytes to be transferred (len) should be 40 which corresponds
> to the block transfer of length 0x28 (from opcode 01000028). Instead we
> have a length of 36 (0x24). The code responsible for this is (in 
> 'lsi_do_dma'):
>
> if (count > s->current_dma_len)
>    count = s->current_dma_len;
>
> Basically we're overwriting the length 40 with the value 36 which I think we 
> just left over in that variable from an earlier transfer. In my patch below I 
> initialize s->current_dma_len to s->dbc before we begin the DMA transfer 
> during Data In phase.
>
> The attached patch gets Openserver 5.0.5 past the hardware detection
> (and it lists the hard drive to boot, woohoo). It appears to stop a little
> while later (doesn't seem SCSI related), but it's been so long since I've
> booted Openserver I'm not sure what's supposted to happen after the HW
> detection using the boot/root disks.
>
> Give it a shot. Hopefully it doesn't break other OS's, but I haven't checked 
> myself. If what I did makes sense and doesn't break anything I'd like to see 
> it get merged into mainline.

It makes sense and doesn't break x86/Linux for me, if there's no
opposing comment for a moment, I'll merge this change.

Cheers