Subject: Re: Success - G4 SCSI
From: Barry Schiffman (bschiff@cs.columbia.edu)
Date: Thu Apr 13 2000 - 05:10:15 MDT
I also have a G4 with scsi drives and I'm following the suggestions below,
and I'm on my way, but I'm a bit confused about the Mac's numbering scheme.
Since I have both the internal scsi drive and an external scsi attached to
the same ATTO card (what Apple put in) I have two entries in the device
tree:
/pci@f2000000 .... ProULD@4
and
/pci@f2000000 .... ProULD@4,1
I'm curious about what the "4" and "4,1" mean.
The system profiler identifies the internal drive as scsi 0 on Bus 2, and
the external drive as scsi 6 on Bus 1, and they show up as /sdb and /sda,
respectively in perldisk in the installer. (both have linux partitions).
So the "4" and the "4,1" don't line up with the bus numbers. I guess I can
try each in turn, but ...
Thanks,
Barry
>
>
> Whew. Thanks to Jim's suggestion, I managed to work through all the
> details and got YDL1.2 to boot on my 450mHz G4 Sawtooth with SCSI disks.
>
> Here's the conundrum: BootX won't work, so you have to use yaboot.
> Unfortunately, yaboot likes to use open firmware aliases and there
> aren't any for your SCSI drives. So, it appears that yaboot won't work
> with SCSI. However, this isn't true. It will work if you specify
> fully-qualified device names (just like you would have to in linux if
> you didn't have aliases or soft links to complex paths). I guess that
> sooner or later I'll figure out if it's possible to set up the aliases
> in OF, which will make this procedure a lot easier. For now, though, I
> have it working and so will probably proceed onto the rest of the
> installation.
>
> Heres what you do:
>
> Install YDL1.2 by booting the CD and following the instructions. This
> should go off without a hitch. Be careful to remember the SCSI device
> ID and number of the boot partition. You'll see why you need this in a
> sec. Also, load your MacOS Software Install CD. If things get screwed
> up, you can always reboot from that. It will be important to be able to
> reset your startup drive because you'll be messing with OF's boot-drive
> environment variable. If you mistype something, all you have to do is
> reboot from the CD and reset the startup disk using the control panel
> and reboot.
>
> So...
>
> First--boot your system holding option-command-O-F. You'll wind up in a
> white forth interpreter screen. Forth is one of the few languages
> that's older than I am, having been designed to run telescopes by people
> who spent their daytimes sleeping. If you know forth, you will have no
> trouble figuring out what to do at the prompt. Otherwise, you'll be
> completely lost, as I was.
>
> (There are a few Apple tech notes on the topic of the OF environment.
> These are technotes 1062, 1061, and 1044. Unfortunately, they hardly
> describe what you might need to know to fully appreciate the
> environment. But they do describe barely enough for you to figure out
> how to make sense of what's going on in this weird place. If you want to
> waste a Saturday figuring this out, like I did, read away...)
>
> The first thing you have to do is to figure out what the path name is to
> the partition on your linux boot disk.
>
> Type: dev / ls
> to see your device tree. Be careful here, neatness counts. Type
> dev<space>/<space>ls. Be careful where you put your spaces as they'll
> be interpreted differently than you would expect coming from a linux (or
> other) environment.
>
> When this works you'll see a hierarchical representation of your
> hardware in ascii form. What you have to do is figure out where your
> linux boot partition is by looking at this mess. And it won't be
> entirely obvious how to do that.
>
> The device tree will list devices down to a certain level of detail. It
> will stop at leaves that are just shy of the SCSI device id you're
> looking for. But you won't have any problem if you've written down your
> SCSI device and boot partition from the install.
>
> Now you have to use your knowledge of the G4 hardware to figure out
> what's what. My G4 SCSI card is an ATTO ExpressPCIPro. (You can find
> this out by looking at the Apple Web Site, using the Apple System
> Profiler, or simple logical deduction after looking at the device tree.)
>
> The card is plugged into a pci port that's been assigned an address of
> F2000000. Between the pci controller and the card is a pci bridge.
>
> In the device tree, I see this:
> ...
> /pci@f2000000
> ...
> /pci-bridge@d
> ....
> /ATTO,ExpressPCIProUL2D@4,1
> ...
> /sd
>
> where the (...) means there's a lot of other junk intervening.
>
> What this says is that the path to at least one of the disks can be
> written like:
>
> /pci@f2000000/pci-bridge@d/ATTO,ExpressPCIProUL2D@4,1/yaddayadda
>
> You've probably noticed that "yadda yadda" isn't in the device tree.
> "/sd" is in the device tree, but this isn't helpful. It's apparently an
> alias to something that hasn't been assigned. And what hasn't been
> assigned is the SCSI ID.
>
> The full path name with SCSI ID and partition looks like this
>
> /pci@f2000000/pci-bridge@d/ATTO,ExpressPCIProUL2D@4,1/@6:5
>
> where 6 is the SCSI ID number of the drive in question, and 5 is the
> partition on the drive.
>
> Now that you know what the fully-qualified path name should be to your
> disk, reboot in MacOS by typing "boot" or "reset-all".
>
> To make yaboot work, be sure to use yaboot_0.5. For reasons I do not
> understand versions prior to 0.5 are not recognized by OF--at least not
> by MY OF on my G4.
>
> To make yaboot work I put it at the "root" level of a MacOS partition on
> a SCSI drive with ID #6. "Root" level means this--when the Mac desktop
> boots--double click your hard drive icon. Put yaboot_0.5, yaboot.conf,
> and vmlinux in that window. Don't put them in a folder. (There's
> actually no reason you have to put these at the root level other than
> they make the typing easier. You can put them anywhere, just remember
> to fully qualify the name when you're writing yaboot.conf)
>
> My MacOS partition is also #6. My linux boot partition is on the same
> SCSI drive at partition #7. My yaboot.conf looks like this:
>
> -----
>
> init-message = "\nWelcome to Yellow Dog Linux!\nHit <TAB> for boot
> options.\n\n"
> timeout = 10
> default = linuxppc
>
> image =
> /pci@f2000000/pci-bridge@d/ATTO,ExpressPCIProUL2D@4,1/@6:6,\vmlinux
> label = linuxppc
> root = /dev/sdc7
> novideo
> ----
>
> I've also created a bootinfo.txt file which allows me to dual boot
> either to MacOS or Linux using BenH's script. Here's the file, just as
> Ben suggests we use it:
>
> ----
>
> <CHRP-BOOT>
> <COMPATIBLE>
> iMac,1 PowerMac1,1 PowerBook1,1 PowerMac2,1 PowerMac3,1 PowerBook2,1
> </COMPATIBLE>
> <DESCRIPTION>
> Yellow Dog Linux Bootloader
> </DESCRIPTION>
> <BOOT-SCRIPT>
> " get-key-map" " keyboard" open-dev $call-method
> dup 20 dump
> 5 + c@ 08 = if
> " Booting MacOS..." cr " boot
> /pci@f2000000/pci-bridge@d/ATTO,ExpressPCIProUL2D@4,1/@6:6,\\:tbxi" eval
>
> else
> " Booting Yaboot..." cr " boot
> /pci@f2000000/pci-bridge@d/ATTO,ExpressPCIProUL2D@4,1/@6:6,\yaboot" eval
>
> then
> </BOOT-SCRIPT>
> </CHRP-BOOT>
>
> ----
>
> Placement of spaces is critical in this file. You have to type it
> EXACTLY like this or you get unpredictable results.
>
> What happens is that when you boot your system, if you hold down the
> space bar (ASCII 20) you'll boot into MacOS. If you do nothing, yaboot
> will take over and shoot you into YDL.
>
> Okay. Next step. Now you have to go back into OF and set it up to
> point to yaboot instead of it's traditional place to start MacOS,
> \\:tbxi.
>
> Reboot and hold down option-command-O-F. Now you're back in weird world
> again.
>
> At a prompt type
>
> setenv boot-device (FILL IN YOUR FULLY QUALIFIED DEVICE NAME + either
> the path to yaboot, or the path to the dual boot script file you created
> above)
>
> mine looks like this:
>
> setenv boot-device
> /pci@f2000000/pci-bridge@d/ATTO,ExpressPCIProUL2D@4,1/@6:6,\bootinfo.txt
>
> bootinfo.txt is the file containing the dual boot script. If I just
> wanted to boot into linux all the time, I'd have said:
>
> /pci@f2000000/pci-bridge@d/ATTO,ExpressPCIProUL2D@4,1/@6:6,\yaboot
>
> where "yaboot" is the name of my yaboot_0.5 file as I downloaded it from
> BenH's site.
>
> Type "boot" (without the quotes) and watch it work. ...or...if it
> doesn't work you can either reboot into OF and make sure you didn't
> mistype something, or you can boot from your MacOS software install CD,
> reset the startup disk, and edit your bootinfo.txt and yaboot.conf
> files.
>
> Now, whenever I reboot my G4, OF will launch it over to my bootinfo.txt
> script on the 6th partition of my #6 SCSI drive on my SCSI2. The script
> will run and see if I'm holding down the space bar. If I am, I get
> MacOS. If not, I get YDL.
>
> I have no idea if booting this way somehow destabilizes the overall
> system. And, I'll probably have to add a few things to my yaboot.conf
> to make the graphics work in X right from the start.
>
> But, I thought it was going to be totally hopeless, and it turned out it
> works.
>
>
> Hope that was helpful.
>
> Joe
>
>
This archive was generated by hypermail 2a24 : Sun Apr 23 2000 - 22:14:39 MDT