No, I have a cramfs on flash and the kernel uses it directly from flash, extracting what it needs to execute. I'm not using initrd then, I have to update in situ, while running.
Bye, Antonio. Tolunay Orkun Scrive: > If your bootloader is U-Boot and you are using standard bootm command to > boot, U-Boot decompresses the initrd image to RAM before passing the file > system to Linux. So, you are not working with flash copy and updating the > flash copy is not a problem at all. This applies to ext2, cramfs or > squashfs based initrd. > > You can keep working as long as you like until it is time to reboot. > > Antonio Di Bacco wrote: >> Yes, I also thought this too. Anything important should stay already in >> RAM but there is a chance that something bad could happen. Probably the >> best thing is what you suggested as second option but I have not so much >> ram. My CGI writes the downloaded new software in RAM and then I should >> directly jump to u-boot without leaving Linux the chance to mix things up >> and then u-boot should copy the RAM to the flash. It seems a strange >> procedure but what else could be done with 4MB flash and 16 MB ram? >> >> Bye, >> Antonio. >> >> On Thursday 20 April 2006 22:18, White wrote: >>> make it easy: if you start an application which do the flash and after >>> this a reset.. nothing should happen. I do it that way. >>> the application resist completly in RAM .. and all important libs are >>> in RAm or in Filesystem Cache. >>> It's only important that you pretend any Application from accessing >>> Datafiles or start of new application ... >>> >>> Alternativly, you can put it in a reserved RAM Area ( mark it not >>> usable by Linux) and put a Flash Code in your Bootloader (U-boot?) >>> after a reset.... >>> >>> But overwrite a cramfs works for me on >100 times without problems. >>> >>> Am Thu, 20 Apr 2006 21:54:45 +0200 schrieb Antonio Di Bacco >>> >>> <antonio.dibacco at aruba.it> : >>>> Yes you are right, it is not a good idea to overwrite working cramfs >>>> filesystem. But what happens if I download the new cramfs plus kernel >>>> in >>>> RAM, do a checksum and then, completely in kernel mode, disabling all >>>> the >>>> interrupts, I write to flash? No process could complain that I am >>>> overwriting because no one is executing. >>>> >>>> Bye, >>>> Antonio. >>>> >>>> On Wednesday 19 April 2006 09:42, Wojciech Kromer wrote: >>>>> Dnia 2006-04-06 22:38, U??ytkownik Antonio Di Bacco napisa??: >>>>>> Hi, >>>>>> >>>>>> how could I upgrade my cramfs rootfs? I have a CGI in the rootfs that >>>>>> receives the new rootfs from a web interface and then tries to write >>>>>> it in the flash. While overwriting the old cramfs, the CGI will >>>>>> continue to work? something weird could happen? >>>>> Generally it's not a good idea to override working filesystem ( I've >>>>> tried to do it once). >>>>> >>>>> You can have two separate copies of filesystem, one to work with, and >>>>> another to overwrite, it requires more flash. >>>>> Another way is working in initrd, it requires more RAM. >>>>> You can also use jffs2 or jffs3 (experimental) to have read-write >>>>> filesystem, and change applications only, not whole filesystem (be >>>>> carefull with changing busybox or libraries!) >>>> _______________________________________________ >>>> Linuxppc-embedded mailing list >>>> Linuxppc-embedded at ozlabs.org >>>> https://ozlabs.org/mailman/listinfo/linuxppc-embedded >>> _______________________________________________ >>> Linuxppc-embedded mailing list >>> Linuxppc-embedded at ozlabs.org >>> https://ozlabs.org/mailman/listinfo/linuxppc-embedded >> _______________________________________________ >> Linuxppc-embedded mailing list >> Linuxppc-embedded at ozlabs.org >> https://ozlabs.org/mailman/listinfo/linuxppc-embedded >
