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RE: FLASH file system
- To: Andrew Lunn <andrew dot lunn at ascom dot ch>, "Simpkins, Andy" <Andy dot Simpkins at Transcomm dot uk dot com>
- Subject: RE: [ECOS] FLASH file system
- From: "Simpkins, Andy" <Andy dot Simpkins at Transcomm dot uk dot com>
- Date: Mon, 3 Sep 2001 10:16:57 +0100
- Cc: "eCos-Discuss (E-mail)" <ecos-discuss at sourceware dot cygnus dot com>
Andrew,
What I am looking for is something like the following...
- Ability to read and write files to FLASH
- Because BLOCK size in flash is typically quite large (>64K) then it is
desirable to split blocks into sub-blocks of a more reasonable size.
- This now leaves the problem of erasing (as the smallest erase size is 1
block).
- By leaving 1 Block free space in the file system at all times it is
possible to 'juggle' data around (i.e. defragmenter) such that sub-blocks
no-longer in use may be freed up for re-use.
- Obviously this will require 1 (or 2) blocks (possibly of a smaller size)
to maintain the FAT.
Do you or anyone else know of such a module available in open source?
If not then I shall have to write one. Cue Red Hat to tell me about what
they would like to see me provide :-)
Andy
> -----Original Message-----
> From: Andrew Lunn [mailto:andrew.lunn@ascom.ch]
> Sent: 03 September 2001 09:34
> To: Simpkins, Andy
> Cc: eCos-Discuss (E-mail)
> Subject: Re: [ECOS] FLASH file system
>
>
> On Mon, Sep 03, 2001 at 09:25:45AM +0100, Simpkins, Andy wrote:
> > Hi there,
> >
> > Does anyone know if there is an eCos FLASH file handling
> module (i.e. treats
> > FLASH as a disk)
>
> The ROM FS can run this the FS in FLASH. Its read only. Is
> that what you mean?
>
> Or do you mean using the flash as a block device? You open /dev/flash
> and read blocks and write blocks? Im not sure that would be very
> efficient. The flash on my device has 256k blocks.
>
> Andrew
>