> Hello,
> I tried to install plan 9 on virtual pc and succedded. But, once
> i boot through plan 9 errors are coming.
> Attached the screen shot of the error.


the plan 9 ide driver apparently disagrees with virtual pc.
this isn't a fossil or venti problem.

unfortunately, i have no access to virtual pc so the rest of this
email is a thought experiment ....

command 30
data f09534b0 limit f0964eb0 dlen 8192 status 0 error 0
lba 210592 -> 210592, count 16 -> 16 (16)
0x00 0x04 0xac 0x36 0x03 0xe0 0x58
0x40: e306 0x42: c0000 x48: 00
0x4a 0000

so
the command is write sectors (Cws; 0x30)
lba 0x0336a0 (according to the driver)

the registers say:

0 1 2 3 4 5 6 As
0x00 0x04 0xac 0x36 0x03 0xe0 0x58
error count lba0 lba1 lba2 stat

at lba 0x3036ac (4 sectors to go) status Bsy|Df|Drdy.

i would think you're issuing a command before the device
is ready for you. this patch may help.

minooka; diff -c /sys/src/9/pc/sdata.c /n/dump/2008/0908/sys/src/9/pc/sdata.c
/sys/src/9/pc/sdata.c:1418,1424 - /n/dump/2008/0908/sys/src/9/pc/sdata.c:1418,1424
ctlr = drive->ctlr;
cmdport = ctlr->cmdport;
ctlport = ctlr->ctlport;
- if(ataready(cmdport, ctlport, drive->dev, Bsy|Drq, Drdy, 101*1000) < 0)
+ if(ataready(cmdport, ctlport, drive->dev, Bsy|Drq, 0, 101*1000) < 0)
return -1;

ilock(ctlr);

- erik