[Yaffs] Re: YAFFS2 boot loader
Nick Bane
nick at cecomputing.co.uk
Thu Oct 20 15:14:59 BST 2005
Rakhi Rathi wrote:
> Hi Nick,
>
> Do I need to provide any file system support in bootloader if kernel and
> root fs are going to be stored in seperate partition? Will kernel image
> able to mount root fs stored by boot loader in root fs partiton?
>
The bootloader needs to establish yaffs images for use by a loaded linux
kernel. I typically addin yaffs direct or equivalent functionality so I
can snoop and/or rewrite files but its not 100% necessary. If you do
this thogh, MAKE SURE ECC IS THE SAME in bootldr and linux kernel!! This
is the main cause for grief between bootldr loaded images and kernel usage.
> Why there was need for you to provide JFFS2 / YAFFS2 support in
> bootloader ? I guess it is required only if you need to read / write
> file in root partiton otherwise only for loading kernel and root fs in
> respective partiton, do I need fs support?
See above.
Can this be done on the yaffs list please? It is often helpful for
others to see the traffic.
Nick
cc yaffs list.
>
> Thanks,
> Rakhi
>
>
>
>
>
> On 10/20/05, *Nick Bane* <nick at cecomputing.co.uk
> <mailto:nick at cecomputing.co.uk>> wrote:
>
> Rakhi Rathi wrote:
> > Nick, can you please guide me for below listed things.
> >
> > Looking forward for positive response from you.....
> >
> I was out yesterday till late so I only got your mail this morning.
>
>
> > Thanks,
> > Rakhi
> >
> > On 10/19/05, *Rakhi Rathi* <rakhi5511 at gmail.com
> <mailto:rakhi5511 at gmail.com>
> > <mailto:rakhi5511 at gmail.com <mailto:rakhi5511 at gmail.com>>> wrote:
> >
> > Thanks Nick.
> >
> > I want to write mkyaffsimage and mkyaffs utility for creating
> YAFFS2
> > root fs and formatting / programming big/small blocks. I am
> > clueless how can I do that? Could you please give me some
> guidance
> > for the same? I will share the code on YAFFS website too.
> >
> It has been a fair while since I looked at mkyaffsimage so I will leave
> it to others on the list to help there. In principle it is simple, you
> chunk the world up into pages and oob info and write that to a file. You
> should probably read the mkyaffsimage source and be at least slightly
> familiar with it first and then ask some specific questions.
>
> > I want to do this for my own interest and to take first step to
> > contribute to open source community.
> >
> This is best done on the yaffs list so others can contribute and make
> suggestions. I know it is on the todo list for several people and it
> may
> already have been done. I have cc'd this to the list for comments.
>
> > Also, could please help me with tar of bootldr35 code.
> >
> Use wget
> http://husaberg.toby-churchill.com/releases/development/bootldr/bootldr35
>
> I can tar it up if wget is not helpful to you.
>
> Nick
>
> > --Rakhi
> >
> >
> >
> > On 10/18/05, *Nick Bane* < nick at cecomputing.co.uk
> <mailto:nick at cecomputing.co.uk>
> > <mailto:nick at cecomputing.co.uk
> <mailto:nick at cecomputing.co.uk>>> wrote:
> >
> > Rakhi Rathi wrote:
> >> Thanks Nick.
> >>
> >> I need some more inputs:
> >>
> >> NAND flash are shipped with bad blocks; what will happen if
> > you try to
> >> load the bootldr using JTAG in block which is bad initially?
> >>
> > Well, we jtag out bootldr into a small bit of NOR and
> avoid the
> > question
> > entirely.
> > However, reading/writing nand is just a convoluted form of
> > reading/writing NOR so in principle it shouldn't be a
> problem.
> >
> > A bigger problem is booting out of NAND. Have you solved that
> > one yet?
> > Only the 2k parts do that and one has to hope that the first
> > page won't
> > become bad with time ...
> >
> >
> >> Once again thanks for all your help.
> >>
> > Happy to do so.
> >
> > Nick
> >
>
>
>
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