Folks, I have one concern regarding FFS. If you use flash for your entire filesystem including /var/log, /proc, etc.., you will be accessing flash too many times.
And there is good chance that, your flash on the board reaches maximum number of accesses/writes limited by flash technology. How do people generally handle that in the industry. Especially, if you have on-board (non-replaceable) flash? Thanks, Prakash Jaap Jan: Thank you very much for precise instructions. --- Jaap-Jan Boor <jjboor at lucent.com> wrote: > Prakash, > > You should divide your flash into parts. e.g.: > > - first block(s) boot > - then some blocks for the kernel > - all remaining blocks as root fs > > You do this partitioning in the maps directory of > drivers/mtd. > > You can make a linux kernel with mtd and jffs2 > support and ramdisk that > holds the erase, eraseall, dd, mkfs.jffs2 etc. > programs. > > You can load the kernel into SDRAM, run it, prepare > your flash (erase flash, then use mkfs.jffs2 on a > /dev/mtd? device > to prepare an fs. > > You should then make a new kernel that uses mtd as > rootfs, not > the ramdisk as rootfs. > > Jaap-Jan > > Prakash kanthi wrote: > > > > Hi Jaap Jan, > > > > Thanks for your reply. What do you mean by 'works > out > > of the box with denx'? I see the code you referred > to > > but not sure how to use it. I still have some > > concerns. Like, > > > > 1. How can i initially store the image into flash? > My > > flash chip is on the board. > > 2. How can i boot linux from flash? > > > > 3. Currently i have a 32MB SDRAM along with flash. > I > > have tools to download linux image into SDRAM. > Even if > > i go with MTD/JFFS, my concern is unless linux > runs > > flash can not be accessed and vice versa. > > > > 4. Lets say, i download linux into a safe place in > > SDRAM, boot it and then access flash thru MTD/JFFS > and > > store linux image into flash. Even in this case, > what > > all i need to take care of for making my flash a > boot > > device. > > > > Any detailed documentation is appreciated. > > > > Thanks, > > Prakash > > > > --- Jaap-Jan Boor <jjboor at lucent.com> wrote: > > > Hi, > > > > > > I use strata flash with MTD and JFSS2 as file > system > > > on top of it. Works out of the box with denx' > eldk > > > kernel and > > > toolchain. I've provided my own flash map but > you > > > can also use an existing one (look e.g. in > > > linux/drivers/mtd/maps) > > > > > > Jaap-Jan > > > > > > Wolfgang Denk wrote: > > > > > > > > In message > > > > <20030326070131.88176.qmail at web41202.mail.yahoo.com> > > > you wrote: > > > > > > > > > > I have a 32MB Intel Strata flash on my > PPC405 > > > based > > > > > custom board. I need to create access > > > routines/APIs to > > > > > access the flash. I was thinking of creating > a > > > Flash > > > > > File System and mount it as a device in > Linux > > > > > environment. > > > > > > > > > > Are there any off the shelf FFS packages > > > available? > > > > > Generally, how the flash is used? > > > > > > > > Use the MTD layer. > > > > > > > > > I am working with micro-monitor to use its > Tiny > > > File > > > > > System on flash support and eventually mount > > > into > > > > > linux. Did anyone use this combination > before? > > > > > > > > I think you cannot do this. AFAIK the TFS code > is > > > not available under > > > > a GPL compatible license which prevents it > from > > > being linked with the > > > > Linux kernel code. > > > > > > > > Best regards, > > > > > > > > Wolfgang Denk > > > > > > > > -- > > > > Software Engineering: Embedded and Realtime > > > Systems, Embedded Linux > > > > Phone: (+49)-8142-4596-87 Fax: > (+49)-8142-4596-88 > > > Email: wd at denx.de > > > > There is is no reason for any individual to > have a > > > computer in their > > > > home. -- Ken Olsen (President of Digital > > > Equipment Corporation), > > > > Convention of the World Future > > > Society, in Boston, 1977 > > > > > > > > > > -- > > > J.G.J. Boor > > > Room: BE-525 > > > Lucent Technologies Nederland b.v. > > > Phone: +31 35 687 4721 > > > Optical Networking Group TMS Data > > > Fax: +31 35 687 5976 > > > P.O. Box 1168, 1200 BD, Hilversum, The > Netherlands > > mailto:jjboor at lucent.com > > > > -- > J.G.J. Boor > Room: BE-525 > Lucent Technologies Nederland b.v. > Phone: +31 35 687 4721 > Optical Networking Group TMS Data > Fax: +31 35 687 5976 > P.O. Box 1168, 1200 BD, Hilversum, The Netherlands mailto:jjboor at lucent.com ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
