Re: Partition question...

Re: Partition question...

[Chris Lesiak]

I also have two banks mapped contiguously into virtual memory that I would
like to be seen as one.

The problem is that RedBoot (and ECOS) seems to only support one flash
logical device.  I wrote an ECOS flash driver that treated both banks as a
single large logical device.  RedBoot stores its partition table in the last
erase
block of the device.  So in my case, a single partition table is store in the
last
erase block of the second bank but partitions the space of both banks.

When I get to the linux, mtd seems to expect a partition table for each bank.

What is the best way to reconcile the problem?
Can linux also easily see both banks as a single device that can be partitioned?

Chris Lesiak
clesiak@licor.com



If the addressing between two Flash devices remains linear with no gaps,
can they be part of the same mtd[n] partition, or must the next chip be
mtd[n+1]?

I have two 32-bit Flash devices (or so I'm told). Since this is a MIPS
application the
reset vector is 0xBFC00000. The Flash devices are 0xBE000000-BEFFFFFF and
0xBF000000-BFFFFFFF, so I have 4Megs at the top of the second device, with
the
first device and lower 12Megs of the second giving me 28Megs of linear Flash

available.

Keith Siders
Software Engineer
 Toshiba America Consumer Products, Inc.
Advanced Television Technology Center
801 Royal Parkway, Suite 100
Nashville, Tennessee 37214
Phone: (615) 257-4050
Fax:   (615) 453-7880


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

Re: Partition question...

[David Woodhouse]

On Mon, 10 Sep 2001, Chris Lesiak wrote:

> I also have two banks mapped contiguously into virtual memory that I would
> like to be seen as one.

Should be fine, as long as the two chips are identical. At the moment, 
they need to be mapped with no space between them. However, aliases are 
OK. So, for example, if you have

 0xbe000000-0xbe7fffff Chip 1
 0xbe800000-0xbeffffff Chip 1 again
 0xbf000000-0xbf7fffff Chip 2
 0xbf800000-0xbfffffff Chip 2 again. 

That'll be fine. It'll detect the aliases in there. It will quit scanning 
the region when it finds something that's not a flash chip, though, so if 
those aliases _weren't_ there it'd break (and you could trivially fix it 
the your 'map' driver by munging the addresses).

> The problem is that RedBoot (and ECOS) seems to only support one flash
> logical device.  I wrote an ECOS flash driver that treated both banks
> as a single large logical device.  RedBoot stores its partition table
> in the last erase block of the device.  So in my case, a single
> partition table is store in the last erase block of the second bank
> but partitions the space of both banks.
> 
> When I get to the linux, mtd seems to expect a partition table for each bank.
> 
> What is the best way to reconcile the problem?

Change your map driver to encompass the whole region, then it should 
appear as a single MTD device and it'll look for a single partition table.

> I have two 32-bit Flash devices (or so I'm told). Since this is a MIPS
> application the reset vector is 0xBFC00000. The Flash devices are
> 0xBE000000-BEFFFFFF and 0xBF000000-BFFFFFFF, so I have 4Megs at the
> top of the second device, with the first device and lower 12Megs of
> the second giving me 28Megs of linear Flash

You should be able probe the two chips as a single device with no 
problems, as I said above. But then you want two non-contiguous regions to 
appear as a single partition. 

That's not handled by the existing partition code - but the partition code 
is just a simple set of wrappers that add an offset and pass control 
through to the methods of the underlying MTD device. It's simple enough to 
hack up your own wrapper which does what you want.

-- 
dwmw2

Re: Partition question...

[Alex Liao]

Hi,
    I want to partition my MTD devices , it physical address :
    CS0: 0x00000000 - 0x00800000
    CS1: 0x10000000 - 0x10800000
    How should I to haldle it ?

Thanks..
----- Original Message -----
From: "David Woodhouse" <dwmw2@infradead.org>
To: "Chris Lesiak" <clesiak@licor.com>
Cc: <linux-mtd@lists.infradead.org>; "Siders, Keith"
<keith_siders@toshibatv.com>
Sent: Tuesday, September 11, 2001 3:52 AM
Subject: Re: Partition question...


> On Mon, 10 Sep 2001, Chris Lesiak wrote:
>
> > I also have two banks mapped contiguously into virtual memory that I
would
> > like to be seen as one.
>
> Should be fine, as long as the two chips are identical. At the moment,
> they need to be mapped with no space between them. However, aliases are
> OK. So, for example, if you have
>
>  0xbe000000-0xbe7fffff Chip 1
>  0xbe800000-0xbeffffff Chip 1 again
>  0xbf000000-0xbf7fffff Chip 2
>  0xbf800000-0xbfffffff Chip 2 again.
>
> That'll be fine. It'll detect the aliases in there. It will quit scanning
> the region when it finds something that's not a flash chip, though, so if
> those aliases _weren't_ there it'd break (and you could trivially fix it
> the your 'map' driver by munging the addresses).
>
> > The problem is that RedBoot (and ECOS) seems to only support one flash
> > logical device.  I wrote an ECOS flash driver that treated both banks
> > as a single large logical device.  RedBoot stores its partition table
> > in the last erase block of the device.  So in my case, a single
> > partition table is store in the last erase block of the second bank
> > but partitions the space of both banks.
> >
> > When I get to the linux, mtd seems to expect a partition table for each
bank.
> >
> > What is the best way to reconcile the problem?
>
> Change your map driver to encompass the whole region, then it should
> appear as a single MTD device and it'll look for a single partition table.
>
> > I have two 32-bit Flash devices (or so I'm told). Since this is a MIPS
> > application the reset vector is 0xBFC00000. The Flash devices are
> > 0xBE000000-BEFFFFFF and 0xBF000000-BFFFFFFF, so I have 4Megs at the
> > top of the second device, with the first device and lower 12Megs of
> > the second giving me 28Megs of linear Flash
>
> You should be able probe the two chips as a single device with no
> problems, as I said above. But then you want two non-contiguous regions to
> appear as a single partition.
>
> That's not handled by the existing partition code - but the partition code
> is just a simple set of wrappers that add an offset and pass control
> through to the methods of the underlying MTD device. It's simple enough to
> hack up your own wrapper which does what you want.
>
> --
> dwmw2
>
>
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/

Re: Partition question...

[David Woodhouse]

alex@vistatopology.com said:
>    I want to partition my MTD devices , it physical address :
>     CS0: 0x00000000 - 0x00800000
>     CS1: 0x10000000 - 0x10800000
>     How should I to haldle it ? 

What's at 0x800000-0xffffff? A second image of CS0? If so, just copy one of 
the existing map drivers and make it length 0x10800000. Then after calling 
the chip probe routines you set up your array of struct mtd_partitions and 
call add_mtd_partitions. There are plenty of examples to crib from.

--
dwmw2

partition question

[Roelof Wobben]

Hello,

I have one thing I think I don't really understand about btrfs,

Normally if I use ext4 I make a  3 partitions for my distro.

one for boot about 1G
one for home about 30G
one for root for the rest of my 100G.

Now I wonder if I want to do the same with btrfs.

Can I do the same so make 3 partitions with btrfs or can I better make 1 
partiton of 100G and make the /boot /home and  / subvolumes of the big 
partitiion.

Can one of you btfrs gurus shine a light of this matter ?

Regards,

Roelof Wobben

Re: partition question

[Chris Carlin]

On Fri, Jan 11, 2013 at 2:21 PM, Roelof Wobben <r.wobben@home.nl> wrote:
> Hello,
>
> I have one thing I think I don't really understand about btrfs,
>
> Normally if I use ext4 I make a  3 partitions for my distro.
>
> one for boot about 1G
> one for home about 30G
> one for root for the rest of my 100G.
>
> Now I wonder if I want to do the same with btrfs.
>
> Can I do the same so make 3 partitions with btrfs or can I better make 1
> partiton of 100G and make the /boot /home and  / subvolumes of the big
> partitiion.

Well. what is your motivation for doing it that way in the ext4?

If you're looking to be able to selectively mount sections of your
filesystem, then sure, subvolumes might work, but a lot of people
divide partitions this way so that they'd be independent for purposes
of reliability. Subvolumes of one btrfs partition wouldn't provide
that independence.

~Chris

Re: partition question

[Chris Murphy]

On Jan 11, 2013, at 12:21 PM, Roelof Wobben <r.wobben@home.nl> wrote:

> Hello,
> 
> I have one thing I think I don't really understand about btrfs,
> 
> Normally if I use ext4 I make a  3 partitions for my distro.
> 
> one for boot about 1G
> one for home about 30G
> one for root for the rest of my 100G.
> 
> Now I wonder if I want to do the same with btrfs.
> 
> Can I do the same so make 3 partitions with btrfs or can I better make 1 partiton of 100G and make the /boot /home and  / subvolumes of the big partitiion.
> 
> Can one of you btfrs gurus shine a light of this matter ?

You can make one Btrfs volume with /boot, /home, and / as subvolumes. GRUB2 2.00 can boot this arrangement, and that's the first caveat which is that many distributions are using older versions of GRUB2. It even works with Btrfs data/metadata profiles single, dup; and multiple device raid 0, 1, 10; and compression zlib, and lzo.

Swap still needs to be on a separate partition, as I don't think Btrfs is supporting swapfiles yet still, but maybe someone else can comment on the status of that.

While GRUB2 has LUKS support, its easier to have /boot on a separate partition for such purposes.

The limiting factor is an installer that doesn't offer the unified option, and also won't install to a pre-configured Btrfs volume.  I can vouch for Fedora 18, which can do both. That is, it will install to an existing Btrfs volume either reusing or creating subvols for home, boot, usr, var; and it will compel you to create a new subvol for root. Further, it can create new Btrfs volumes. By default with the non-custom partition path, it will put /boot on ext4. If you choose BTRFS in Installation Options > Partition scheme configuration *before* you get to custom partitioning (the screen labeled Manual Partitioning), you will be able to add a Boot mountpoint and change it from ext4 to Btrfs, and set the size however large you want. Any additional mount points other than swap will be created as subvolumes.

Chris Murphy

Re: partition question

[Hugo Mills]

[-- Attachment #1: Type: text/plain, Size: 1725 bytes --]

On Fri, Jan 11, 2013 at 03:34:25PM -0700, Chris Murphy wrote:
> On Jan 11, 2013, at 12:21 PM, Roelof Wobben <r.wobben@home.nl> wrote:
> > I have one thing I think I don't really understand about btrfs,
> > 
> > Normally if I use ext4 I make a  3 partitions for my distro.
> > 
> > one for boot about 1G
> > one for home about 30G
> > one for root for the rest of my 100G.
> > 
> > Now I wonder if I want to do the same with btrfs.
> > 
> > Can I do the same so make 3 partitions with btrfs or can I better make 1 partiton of 100G and make the /boot /home and  / subvolumes of the big partitiion.
> > 
> > Can one of you btfrs gurus shine a light of this matter ?

> You can make one Btrfs volume with /boot, /home, and / as
> subvolumes. GRUB2 2.00 can boot this arrangement, and that's the
> first caveat which is that many distributions are using older
> versions of GRUB2. It even works with Btrfs data/metadata profiles
> single, dup; and multiple device raid 0, 1, 10; and compression
> zlib, and lzo.
> 
> Swap still needs to be on a separate partition, as I don't think
> Btrfs is supporting swapfiles yet still, but maybe someone else can
> comment on the status of that.

   I don't know this area of the code at all well, but as I understand
it, there's been some work in the kernel (swap over NFS) which lays
down some of the underlying infrastructure we'd need to support
swapfiles on btrfs, but we don't have anything beyond that. I don't
know of anyone working on it, either.

   Hugo.

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
  PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
       --- It's against my programming to impersonate a deity! ---       

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 828 bytes --]

Re: partition question

[Roelof Wobben]

Op 11-1-2013 23:38, Hugo Mills schreef:
> On Fri, Jan 11, 2013 at 03:34:25PM -0700, Chris Murphy wrote:
>> On Jan 11, 2013, at 12:21 PM, Roelof Wobben <r.wobben@home.nl> wrote:
>>> I have one thing I think I don't really understand about btrfs,
>>>
>>> Normally if I use ext4 I make a  3 partitions for my distro.
>>>
>>> one for boot about 1G
>>> one for home about 30G
>>> one for root for the rest of my 100G.
>>>
>>> Now I wonder if I want to do the same with btrfs.
>>>
>>> Can I do the same so make 3 partitions with btrfs or can I better make 1 partiton of 100G and make the /boot /home and  / subvolumes of the big partitiion.
>>>
>>> Can one of you btfrs gurus shine a light of this matter ?
>> You can make one Btrfs volume with /boot, /home, and / as
>> subvolumes. GRUB2 2.00 can boot this arrangement, and that's the
>> first caveat which is that many distributions are using older
>> versions of GRUB2. It even works with Btrfs data/metadata profiles
>> single, dup; and multiple device raid 0, 1, 10; and compression
>> zlib, and lzo.
>>
>> Swap still needs to be on a separate partition, as I don't think
>> Btrfs is supporting swapfiles yet still, but maybe someone else can
>> comment on the status of that.
>     I don't know this area of the code at all well, but as I understand
> it, there's been some work in the kernel (swap over NFS) which lays
> down some of the underlying infrastructure we'd need to support
> swapfiles on btrfs, but we don't have anything beyond that. I don't
> know of anyone working on it, either.
>
>     Hugo.
>

Im testing Crux where I must make a custom partiion scheme before I can 
start the installer.
And Im making this scheme before because people told me that was the 
best way to work.

Roelof

Re: partition question

[dima]

>     I don't know this area of the code at all well, but as I understand
> it, there's been some work in the kernel (swap over NFS) which lays
> down some of the underlying infrastructure we'd need to support
> swapfiles on btrfs, but we don't have anything beyond that. I don't
> know of anyone working on it, either.
>
>     Hugo.
>

You can use swapfile on btrfs with mounting it via a loop device. It 
won't be incredibly fast, but it will work.

Re: partition question

[David Sterba]

On Fri, Jan 11, 2013 at 10:38:45PM +0000, Hugo Mills wrote:
> On Fri, Jan 11, 2013 at 03:34:25PM -0700, Chris Murphy wrote:
> > Swap still needs to be on a separate partition, as I don't think
> > Btrfs is supporting swapfiles yet still, but maybe someone else can
> > comment on the status of that.
> 
>    I don't know this area of the code at all well, but as I understand
> it, there's been some work in the kernel (swap over NFS) which lays
> down some of the underlying infrastructure we'd need to support
> swapfiles on btrfs, but we don't have anything beyond that. I don't
> know of anyone working on it, either.

Nobody up to my knowledge.

david

Partition question...

[Siders, Keith]

If the addressing between two Flash devices remains linear with no gaps, 
can they be part of the same mtd[n] partition, or must the next chip be
mtd[n+1]?

I have two 32-bit Flash devices (or so I'm told). Since this is a MIPS
application the
reset vector is 0xBFC00000. The Flash devices are 0xBE000000-BEFFFFFF and 
0xBF000000-BFFFFFFF, so I have 4Megs at the top of the second device, with
the
first device and lower 12Megs of the second giving me 28Megs of linear Flash

available. 

Keith Siders
Software Engineer
 Toshiba America Consumer Products, Inc.
Advanced Television Technology Center
801 Royal Parkway, Suite 100
Nashville, Tennessee 37214
Phone: (615) 257-4050
Fax:   (615) 453-7880