From: chessmylitis@hotmail.com
To: manningc2@actrix.gen.nz
Subject: RE: [Yaffs] (no subject)
Date: Wed, 8 Jun 2011 06:47:08 +0000










> From: manningc2@actrix.gen.nz
> To: yaffs@lists.aleph1.co.uk
> Subject: Re: [Yaffs] (no subject)
> Date: Wed, 8 Jun 2011 17:01:01 +1200
> CC: chessmylitis@hotmail.com
> 
> On Wednesday 08 June 2011 02:10:42 Rhykie Rhykie wrote:
> > Hi,
> > I have two questions:
> >
> > 1) In the cramfs file system i have a source code in which i want to use
> > fread()/fwrite() functions to read/write to a text file in the yaffs file
> > system, all this in a nand flash memory in two different partitions.
> > Unfortunately when compiling i get the "trying to access read-only file
> > system" error. Any idea of how i can achieve what i want to do.
> 
> That is very little info to work on/ Can you explain more?

Ok, the nand flash is divided into four MTD block partitions; in mtdblock2 there is a cramfs file system which comprises my source code. Now since cramfs is read-only, I want to permanently store some text files in mtdblock3 which is a yaffs file system, allowing read and write. Then  from the cramfs[mtdblock2] I want to access those files in [yaffs]mtdblock3 to perform read/write. For example I have the following instruction, in my source code [mtdblock2], to open the file in mtdblock3:
                                                                                          FILE*ft = fopen("/dev/mtdblock3/myfile.txt", "r+");
So I get I get the error! If the file myfile.txt is in mtdblock3 yaffs partition, is its directory written as: /dev/mtdblock3/myfile.txt?

> 
> >
> > 2)When the cramfs file system is configured to be the root after kernel
> > boot-up, i have read that i can mount the yaffs to mtdblock3 partition by
> > using the command mount -t yaffs /dev/mtdblock3 /mnt/.
> >
> > In the /mnt directory, i get the empty yaffs folder. As i was researching
> > about how to get going with yaffs i got a couple yaffs source code which i
> > dont know how to use them. Please help, how do i get a yaffs file system in
> > the nand partition.
> 
> First, start off with an empty flash (before you mouint yaffs). You can use 
> flash_eraseall to do this. Mount yaffs, then copy the files in from another 
> source.
> -- Charles