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

[Jamey Hicks <jamey dot hicks at compaq dot com>]

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.

>
>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.

Jamey