decompressing u-boot/PPCBoot image

[Jerry Natowitz]

Looking through /etc/magic, I found this entry:

# u-boot/PPCBoot image file
# From: Mark Brown <broonie-GFdadSzt00ze9xe1eoZjHA at public.gmane.org>
0       belong  0x27051956      u-boot/PPCBoot image
 >4      string  PPCBoot
 >>12    string  x               version %s

Perhaps that email address is still current.

	Jerry Natowitz
	j.natowitz-KealBaEQdz4 at public.gmane.org


Tom Metro wrote:
> A while ago I purchased an IP camera, in large part because it said it 
> ran Linux. It's manufactured by a Taiwanese company (but I'm not sure 
> who), and sold by a US distributor[1], which has since discontinued 
> carrying it, but it still appeared to be carried elsewhere[2].
> 
> Shortly after receiving it I sent a request to the reseller for the 
> source code, which was ignored (though they responded to other tech 
> support issues). If I had not been in a rush to deploy the camera, I 
> would have sent it back at that point. Now that they've discontinued 
> carrying the product, I might be able to get the name of the 
> manufacturer out of them, and I'll try contacting the manufacturer 
> directly, but I'm not too hopeful.
> 
> So I was looking at the firmware update the reseller supplied to me to 
> see what might be learned from it, and whether it presented any 
> opportunities for hacking into the device. The file they sent has a .gz 
> extension, implying gzip of course, but gzip doesn't recognize it. The 
> 'file' command reports that it is a "u-boot/PPCBoot image." Googling 
> that or portions of that hasn't told me much, but this posting:
> 
> http://lkml.indiana.edu/hypermail/linux/kernel/0404.2/1394.html
> 
> suggests that this type of file can contain a gzip image at an offset (I 
> presume following a boot loader of sorts), so I scanned through the file 
> looking for the first 4-bytes that seem to signify a gzip file, and 
> found nothing. Same for a bzip2 header. Yet the data stream appears 
> random, as compressed data would.
> 
> Does anyone know how to decompress a u-boot/PPCBoot image file?
> How about a source of information on the file format? Does PPC refer to 
> Power PC architecture? u-boot seems to show up frequently in the context 
> of USB booting.
> 
> 1. http://www.gadspot.com/
> 2. http://ipcamerastore.ecrater.com/product.php?pid=2161747
> 
>   -Tom
>