On Sat, 8 Nov 2008, T. Makinen wrote:
On Fri, Nov 7, 2008 at 5:57 PM, David Brownlee <abs%netbsd.org@localhost> wrote:
OK, found the issue. Would you believe it was an unmatched
quote? :)
Could you try http://mono.org/abs/sysinst2.fs.gz
It should give you a message like
"Mounted /dev/md2a read-write"
before prompting for keyboard layout and running sysinst.
I tried this with Falcon, now there's different problem; after sysinst
is
loaded, it starts to loop following messages:
erase ^H, werase ^W, kill ^U, intr ^C
mount: cannot open '/dev/md2a': no such file or directory
Unable to mount /dev/md2a read-write
I can break to sh shell with Cntr-C and there are only: md0a, md0c and
md1a,
md1c devices in /dev ...
sysctl -n kern.root_device kern.root_partion returns
md2
0
I wonder why md2a does not exist in /dev, but it can be used as root
device
to launch installer ?
I tried with fd0a device and it launches installer as assumed (I tried
it to
the point when it prompts for keyboard layout).
Could you try http://mono.org/abs/sysinst3.fs.gz ?
OK, cue long explanation about device nodes and mountpoints
(just skip any parts you already know :)
/dev contains device special files, which are just there to
provide a way for a userland program to pass a reference to
a device into the kernel.
Each device special file contains a major and minor numeric
id, these index into a table in the kernel.
Whether a device has an entry in /dev doesn't affect the
kernel access to that device, but it does stop a userland
program from passing the details of what device to access
to the kernel.
The root filesystem is a special case - it needs to be
mounted before /dev can be accessed, so the kernel
fakes up a rootdev device path when it mounts it before
it starts running init.
Its a special case again in that if there is no 'real' /dev/
entry for the root filesystem there is no way for the mount
command to tell the kernel to remount it read-write.
Once the root filesystem (or any filesystem) is mounted
read-write you can use the mknod(8) or MAKEDEV(8) commands
to create files for any device nodes you want.
<aside>
Actually there is a cute way around this which is used by
some installers - the mount_mfs(8) command will allocate
a block of memory and mount it on a directory, so init(8)
has a special test - if it cannot locate /dev/console it
opens /dev/MAKEDEV, then runs mount_mfs(8) to mount a
ramdisk on /dev, copies the old /dev/MAKEDEV (now hidden
under the mountpoint but still readable as it has it open)
to /dev/MAKEDEV and then runs it.
This gives a read-only root filesystem, but a read-write
/dev. Now init can start up the system as normal.
</aside>
If you search for 'floppy' in /dev/MAKEDEV on a NetBSD/atari
box you will see it only contains md0 and md1. I'll update
the version in tree, and have built a new sysinst3.fs.gz :)
--
David/absolute -- www.NetBSD.org: No hype required --