I've noticed two things over the weekend.
1) sun-parts seems to be off by 1 (it is counting the vtoc as the first partition, which it should not , AFAIK). I will submit a patch when I get a chance.
2) I am getting a bit further with the Solaris boot if I enable all the QEMU debugging (-d in_asm,exec,cpu,op,int,out_asm).
SunOS starts and then I get message:
Cannot load drivers for sd(0,2,0)@0,0:b (or :a with the sun-parts fix)
Can't load the root filesystem
I thinks QEMU emulates SCSI 3 and Solaris wants SCSI 1 or 2. Can we load drivers or emulate a supported environment?
There seems to be some sort of timing issue with the startup. If I disable all QEMU debugging, it starts about1 in 20 times. If I enable it all, about 1 in 2 times.
Hope this helps.