Re: AW: [ECOS] cat zImage >/dev/mtd1 does not work

[Gary Thomas <gary at mlbassoc dot com>]

Weiguang Shi wrote:
> Thanks very much Alex. That makes things clear.
>
> Now for the CDL (please excuse me since I'm a newbie
> to RedBoot), could you explain more? Do I need to build
> Redboot with the correct options and store it in the
> flash?

Note: you don't really need to change RedBoot.  Just update the
FIS [directory] entry for the image you are changing, either with
the corrected checksum, or the value 0.  RedBoot ignores the checksum
when the stored value is 0.

> --- "Neundorf, Alexander" <Alexander.Neundorf@jenoptik.com> wrote:
>
> > > Von: ecos-discuss-owner@ecos.sourceware.org
> > >
> > > Hi, 
> > >
> > > I'm running snapgear-3.4.0 on an IXDP425 board with RedBoot as 
> > > the bootloader and I want to
> > > be able to upgrade my kernel and filesystem, i.e., zImage and 
> > > ramdisk.gz on the flash, under Linux.
> > >
> > > So I shipped the zImage and ramdisk.gz onto the running system
> > > and did
> > >     # cat zImage >/dev/mtd1
> > >     # cat ramdisk.gz >/dev/mtd2
> > >
> > > after eraseall the two partitions. To my surprise, when I reboot,
> > > RedBoot gave 
> > >                         RedBoot> fis load ramdisk             
> > >                 
> > >                         ** Warning - checksum failure.  
> > > stored: 0x33dbe19b, computed:
> > >                         0xc9d7dfef                            
> > >                 
> > >                         RedBoot> fis load kernel              
> > >                 
> > >                         ** Warning - checksum failure.  
> > > stored: 0xfb99dd45, computed:
> > >                         0x788bb713                            
> > >                 
> > >                         RedBoot> exec -c 
> > > "console=ttyS0,115200 root=/dev/ram0 
> > >                         initrd=0x00800000,6M 
> > > mem=32M@0x00000000" 0x01600000   
> > >                         Can't execute Linux - invalid entry 
> > > address           
> > > and refused to boot.
> > >
> > > I understand here the newly flashed images (as it was not 
> > > done in RedBoot but in the OS) may
> > > not have the same checksum as RedBoot calculated for the 
> > > earlier images. And this caused the problem.
> > When Redboot stores an image, it stores:
> > -the actual data length
> > -the size of the "partition"
> > -the calculated checksum
> >
> > If the checksum doesn't match, it fails.
> > If the actual size of the kernel is bigger than what it stored in the FIS, it won't load
> > everything and it probably will not work.
> >
> > You could:
> > -disable the checksum in Redboot, I think this is possible via a cdl option
> > -when storing the kernel via Redboot, use the partition size also as data length, so it will
> > always load everything as long as it fits in the partition

--
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------

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