[uClinux-dev] how to upgrade the jffs2 of root in linux

Wed Oct 17 09:21:49 EDT 2007

Hi, 

With minimal memory alternative options would be to stream the image to your flash.

If your system is minimal, maybe you do not need to keep a flash fs mounted.  Can your system remain up if you unmount the existing jffs root?  

If so, and if ram/flash is at a premium, it is possible to execute a simple program that does all upgrade.

The program would need to:

- unmount root, e.g. system( "umount /dev/root" )
- use mtd calls to unlock/erase flash
- receive upgrade package. .
- as file comes in, write to flash.
- once written to flash ok, the partition can be remounted from within the process, e.g. system( "mount <root dev>") 
- if the program is running from a /tmp tmpfs, it could be restarted on failure, until the rootfs is restored. 

Rather then write a program from scratch, one of the simple embedded web servers out there can be modified to recieve post of file.   I believe uclinux has sparse httpd.

If you do something like this the possiblity of failing in the middle of upgrade is likely.  A fail safe image or bootloader with upgrade option would be needed to keep the system recoverable.  

The best place for an upgrade is sometimes the bootloader, maybe when an upgrade is requested, jump to bootloader and leave up to the bootloader.

It may be too that your options for upgrade would improve by minimizing the size of the root partition, or the part that needs to be upgraded.

Just suggestions, I don't know details of your requirments,

Matt

________________________________

From: uclinux-dev-bounces at uclinux.org [mailto:uclinux-dev-bounces at uclinux.org] On Behalf Of advan
Sent: Wednesday, October 17, 2007 5:35 AM
To: uClinux development list
Subject: Re: RE: Re: [uClinux-dev] how to upgrade the jffs2 of root in linux

Hi,Matt 
the  netflash also needs enough memory space ,when I use './netflash -K -r /dev/mtd1 192.168.1.218 jffs2.bin' via tftpserver through ethernet , the netflash requestes  virtual memory  always to store the data and that it's very slow . like my case , the embedded device's memory is very limited . free memory is only 1M ,otherwise the size of jffs2.bin is 3M , it seems it's difficult to netflash too , 
what do you think ? 
Thank you very much 

Best Regards 
                              cookie 

________________________________

advan
2007-10-17
________________________________

·¢¼þÈË£º Crane, Matthew
·¢ËÍÊ±¼ä£º 2007-10-16 21:16:37
ÊÕ¼þÈË£º uClinux development list
³ËÍ£º 
Ö÷Ìâ£º RE: Re: [uClinux-dev] how to upgrade the jffs2 of root in linux

Can netflash upgrade a mounted root partition?

If you don't have the memory to mount the tmp partition in ram, then keep a small second tmp partition in your flash, switch to that, run netflash, and then switch back to the new main parttion. 

Matt

________________________________

From: uclinux-dev-bounces at uclinux.org [mailto:uclinux-dev-bounces at uclinux.org] On Behalf Of Nikita Tabatsky
Sent: Tuesday, October 16, 2007 5:06 AM
To: uClinux development list
Subject: Re: Re: [uClinux-dev] how to upgrade the jffs2 of root in linux

Hi, Advan
 yes, netflash it's flash tool.
 sorry, i forgot to insert link :)
http://cvs.uclinux.org/cgi-bin/cvsweb.cgi/uClinux-dist/user/netflash/ 
Nik.

On 10/16/07, advan <advan at rexian.com> wrote: 

	Hi,Nik
	    Thank you , what is netflash ,it's a flash tool ?
	 could you offer a link address ?

	 Best Regards
	                             advan

________________________________

	advan
	2007-10-16

________________________________

	·¢¼þÈË£º Nikita Tabatsky
	·¢ËÍÊ±¼ä£º 2007-10-15 17:54:26

	ÊÕ¼þÈË£º uClinux development list
	³ËÍ£º 
	Ö÷Ìâ£º Re: [uClinux-dev] how to upgrade the jffs2 of root in linux

	Hi, Advan
	You can use netflash for upgrade your jffs2 partition.
	Nik.

	On 10/15/07, advan < advan at rexian.com <mailto:advan at rexian.com> > wrote: 

		hi, everyone 

		  I build jffs2 as root file system in my embedded platform with uclinux os , I also build a web http server(boa) , through httpd server , I can upload a new jffs2 root file-system into the platform memery ,then I want to use new jfffs file to re-write jffs2 partition ,because linux is using this partition as its root file system , if I directly write it into the jffs2 partition ,then linux will cause crash and errors . anybody know how to do ?

		thank you in advance 

		                                   advan

________________________________

		advan

		2007-10-15

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