Hi,

# Sorry, slow response.

>>>>> On Tue, 27 Nov 2001 18:09:27 +1100 (EST), nigel@ind.tansu.com.au said:

nigel> 	Takeshi proposed:
>> And, What environ variable does Booter return for IDE?
>> It's ROOT_ATA_ID? If it is, we should add


nigel> 	Good suggestion.
nigel> 	My question is how do we encode the buss & device.
nigel> Three suggestions:

I think you understand the bootup mechanizm from ffs and hfs,
because it's a issue which loads a kernel in memory and puts 
pointer the entry point.

But it is depend to kernel that a kernel finds root device.

Now, at SCSI disk,

Boot disk is fixed,

controller = 0
scsi id = getenv("ROOT_SCSI_ID")
lun = 0
bus = any???
patition = a

So, in mac68k port, we can boot up only from SCSI disk connected
a internal scsi controller.

nigel> Buss/channel Drive/ID | ROOT_ATA_ID(a)  (b)   ROOT_ATA_DEV(c)
nigel> ----------------------+--------------------------------------
nigel>      0          0     |       0         0,0      wdc0,0
nigel>      0          1     |       1         0,1      wdc0,1
nigel>      1          0     |       2?        1,0      wdc1,0
nigel>      1          1     |       3?        1,1      wdc1,1
nigel> ----------------------+--------------------------------------

nigel> 	I suspect that we should have something similar to
nigel> what the kernel uses, which would mean something like (c).
nigel> I eagerly await peoples' discussions and votes.

up to you, but, 

if you can implement on Booter in following,

getenv("ROOT_ATA_ID") = 0 or 1 or 2 or 3 ( I have no good idea. )

I can make codes which find root device in IDE disk.

Now, in Booter, there is input form for ATA ID, but no variable is
returnd to kernel.

nigel> 	Lots of assumptions there, but once we get fast SCSI
nigel> cards working, everyone will want them (eBay will be busy!),
nigel> so it would be nice to have the facility beforehand.

In my recognization, there is no method for finding a root device on
nubus SCSI controller, but we can boot up from a disk connected nubus SCSI
controller, and put root partition on a disk connected internal SCSI controller.

Takeshi Shibagaki
sibagaki@lsi.melco.co.jp