[ECOS] Re: [iPAQ] Restore CE (or bootldr) from Redboot?

[Gary Thomas <gthomas at redhat dot com>]

On Tue, 2002-02-05 at 11:27, Jamey Hicks wrote:
> Gary Thomas wrote:
> 
> >On Tue, 2002-02-05 at 09:15, Hicks, Jamey wrote:
> >
> >>Noel,
> >>
> >>The problem is that in this step redboot is overwritten and that you
> >>cannot test the WinCE installation until after redboot is overwritten.
> >>
> >>>>If you're running a recent ROM RedBoot (with Parrot loader intact):
> >>>>  RedBoot> load -r -b 0x100000 flash_00000000.bin
> >>>>  RedBoot> fis write -f 0x50040000 -b 0x140000 -l 0x003c0000
> >>>>If you're running an original ROM RedBoot (with no Parrot loader):
> >>>>  RedBoot> load -r -b 0x100000 flash_00000000.bin
> >>>>  RedBoot> fis write -f 0x50000000 -b 0x100000 -l 0x00400000
> >>>>
> >>If the installation was not successful, and it is often unsuccessful the
> >>first time, you will be left with only the parrot firmware to restore
> >>the image.  If you have a PCMCIA or CF sleeve, then there are other
> >>instructions for restoring WinCE, but that is also quite error prone.
> >>My experience is that this path often leads to bricks arriving in my
> >>office for reflashing.
> >>
> >Would it also not be this step that could fail when installing bootldr?
> >
> It is still possible, but installing the bootldr does not take much time 
> and is easy to verify, even by hand.
> 
> >>However, if first you replace parrot with bootldr, then you can restore
> >>the entire WinCE image and test it while maintaining bootldr in flash,
> >>yielding the opportunity to load it multiple times or to find a working
> >>image if the saved image was corrupted by xmodem or whatever.
> >>
> >
> >What do you mean by "test" the WinCE image
> >
> I mean boot WinCE.  Unless you boot WinCE, you cannot verify that 
> someone has installed an uncorrupted copy of the WinCE binary.  One very 
> common problem during WinCE installs is installing the 
> flash_00x00000.bin files in the wrong place in Flash.  If you overwrite 
> RedBoot before you boot WinCE, you're out of luck unless you have a 
> flash card that parrot can restore from.  Most people restoring WinCE do 
> not have this, judging from the email and iPAQ's I have received. 
>  Corrupted WinCE images seems to be another common problem.
> 

So how does this work?  Is there some way to load the WinCE image into
RAM and then "boot" it (i.e. run it)?

> >
> >Notice that since RedBoot does not write to the FLASH directly during
> >the load command (it's a separate step/process), there is always the
> >opportunity to "test" or "verify" what's been downloaded.  Just use the
> >"cksum" command, which performs the same checksum operation as the Linux
> >program of the same name.  If the checksums match, then it should be 
> >safe to continue and write the image to FLASH.  Additionally, since 
> >there is sufficient RAM to hold the entire WinCE image, you can reduce
> >the FLASH writing step to a single command (I didn't do it here for 
> >clarity of what was being done) which reduces the possibility of typos
> >even more.
> >
> >>In addition, bootldr-2.18.01 enables you to load a gzipped image in one
> >>shot, which increases the speed and decreases the chance of error.
> >>
> >
> >RedBoot also supports downloading gzip'd images.  Just add the "-d" 
> >switch to the "load" command.
> >
> OK, that is helpful for people who have redboot installed who want to 
> restore wince_image.gz.  That gets the restore down to one step.  It's 
> still a one-shot restore, but it's much more likely to be correct the 
> first time around.  I  still prefer giving people the opportunity to try 
> it again if something went wrong the first time.

For what it's worth, I agree whole-heartedly.  This is exactly why we
moved to keeping the Parrot (HTC) loader in place, so at least the unit
doesn't become a total brick.  Buying a $50 CF RAM card seems like a
pretty good investment for such a unit IMHO.