[9fans] mechanism to bind partitions in /dev?

[9fans] mechanism to bind partitions in /dev?

[Yoann Padioleau]

Hi,

Can someone explain how the partitions in /dev/sdC0/xxx are populated? Who
create those device files? I have a small plan9 kernel running a small shell (sh.Z)
in memory and when I do  'bind #S/sdC0 /dev/' I just see the 'data', 'ctl', and 'raw' files.
There is no 9fat or plan9 or whatever partitions there is on this disk. In fact I've
tried to make on MACos via the Utility disk some fat images and when I do 
qemu -hdb dosdisk.img I can not access again the fat partition on this disk
(I've tried dossrv and then mount /srv/dos/ /mnt #sdC1/data but it does not work).
I can access it though when it's on a floppy disk (mount /srv/dos /mnt /dev/fd0disk
works). How fd0disk is different from #sdC1/data?

Re: [9fans] mechanism to bind partitions in /dev?

[Bruce Ellis]

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disk/prep (and it's mates) are what you need for sdC0. man 8 prep.

brucee


On 18 January 2014 17:57, Yoann Padioleau <pad@fb.com> wrote:

> Hi,
>
> Can someone explain how the partitions in /dev/sdC0/xxx are populated? Who
> create those device files? I have a small plan9 kernel running a small
> shell (sh.Z)
> in memory and when I do  'bind #S/sdC0 /dev/' I just see the 'data',
> 'ctl', and 'raw' files.
> There is no 9fat or plan9 or whatever partitions there is on this disk. In
> fact I've
> tried to make on MACos via the Utility disk some fat images and when I do
> qemu -hdb dosdisk.img I can not access again the fat partition on this disk
> (I've tried dossrv and then mount /srv/dos/ /mnt #sdC1/data but it does
> not work).
> I can access it though when it's on a floppy disk (mount /srv/dos /mnt
> /dev/fd0disk
> works). How fd0disk is different from #sdC1/data?
>
>
>
>

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Re: [9fans] mechanism to bind partitions in /dev?

[Yoann Padioleau]

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Got it, thx a lot.
Just need to do  fdisk -p /dev/sdC0/data > /dev/sdC0/ctl
and then prep -p /dev/sdC0/plan9 > /dev/sdC0/ctl


On Jan 17, 2014, at 11:17 PM, Bruce Ellis <bruce.ellis@gmail.com<mailto:bruce.ellis@gmail.com>> wrote:

disk/prep (and it's mates) are what you need for sdC0. man 8 prep.

brucee


On 18 January 2014 17:57, Yoann Padioleau <pad@fb.com<mailto:pad@fb.com>> wrote:
Hi,

Can someone explain how the partitions in /dev/sdC0/xxx are populated? Who
create those device files? I have a small plan9 kernel running a small shell (sh.Z)
in memory and when I do  'bind #S/sdC0 /dev/' I just see the 'data', 'ctl', and 'raw' files.
There is no 9fat or plan9 or whatever partitions there is on this disk. In fact I've
tried to make on MACos via the Utility disk some fat images and when I do
qemu -hdb dosdisk.img I can not access again the fat partition on this disk
(I've tried dossrv and then mount /srv/dos/ /mnt #sdC1/data but it does not work).
I can access it though when it's on a floppy disk (mount /srv/dos /mnt /dev/fd0disk
works). How fd0disk is different from #sdC1/data?






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Re: [9fans] mechanism to bind partitions in /dev?

[Steven Stallion]

On Fri, Jan 17, 2014 at 10:57 PM, Yoann Padioleau <pad@fb.com> wrote:
> Hi,
>
> Can someone explain how the partitions in /dev/sdC0/xxx are populated? Who
> create those device files? I have a small plan9 kernel running a small shell (sh.Z)
> in memory and when I do  'bind #S/sdC0 /dev/' I just see the 'data', 'ctl', and 'raw' files.
> There is no 9fat or plan9 or whatever partitions there is on this disk. In fact I've
> tried to make on MACos via the Utility disk some fat images and when I do
> qemu -hdb dosdisk.img I can not access again the fat partition on this disk
> (I've tried dossrv and then mount /srv/dos/ /mnt #sdC1/data but it does not work).
> I can access it though when it's on a floppy disk (mount /srv/dos /mnt /dev/fd0disk
> works). How fd0disk is different from #sdC1/data?

Hi Yoann,

sdC0 and friends are populated by devsd (#S) as a part of some
bootstrap goop. What you will typically find is that only the
drive/partitions used to boot are populated, this is the reason for
the readparts= plan9.ini variable. There are other ways to prompt
devsd to create fs entries at boot - I'd suggest looking through
/sys/src/9/port/devsd.c.

Steve