Hi,

I have a Comtrend CT-5621 which I have successfully booting kamikaze with a 
ramdisk (so I have dd and mtd available), but before I flash kamikaze I want to 
make a backup of the stock (manuacturer's) firmware so that if OpenWRT doesn't 
work with my router (it is Broadcom 63xx-based which has a new experimental 
codebase but no GPL ADSL driver and I don't know if I'll be able to get the 
binary driver working with OpenWRT or not) I can revert to the original 
firmware.

This manufacturer does not make firmware images available for download to end 
users so I can't just reflash a downloaded image via tftp, I first have to 
create an image.

I see devices /dev/mtd0 /dev/mtd1 (and 2 and 3), which are cfe, vmlinux, rootfs 
and nvram respectively.

I know that I can backup the partitions using dd, and my understanding is the I 
can boot into cfe and tftp over a concatenated image to the flash command 
(actually with cfe it is possible to flash after the cfe partition, which would 
probably be better for safety reasons)

The reason I am unsure this will work is the following messages I see with 
kamikaze:

bcm963xx_flash: Read Signature value of CFE1CFE1

bcm963xx_flash: CFE bootloader detected

bcm963xx_flash: CFE boot tag found with version 6 and board type 96348GW-11.

bcm963xx_flash: Partition 0 is CFE offset 0 and length 10000

bcm963xx_flash: Partition 1 is kernel offset 22f100 and length 656d3

bcm963xx_flash: Partition 2 is rootfs offset 10100 and length 35f000

bcm963xx_flash: Partition 3 is nvram offset 3f0000 and length 10000

Creating 4 MTD partitions on "bcm963xx":

0x00000000-0x00010000 : "CFE"

0x0022f100-0x002947d3 : "kernel"

mtd: partition "kernel" doesn't start on an erase block boundary -- force 
read-only

0x00010100-0x0036f100 : "rootfs"

mtd: partition "rootfs" doesn't start on an erase block boundary -- force 
read-only

mtd: partition "rootfs" set to be root filesystem

split_squashfs: no squashfs found in "bcm963xx"

0x003f0000-0x00400000 : "nvram"


The kernel and rootfs parititions start 0x100 bytes after the end of the 
previous partition *and* are not on an erase block boundary.  I am concerned 
that dd'ing mtd1,2, and 3 will therefore be insufficient because there will be 
missing bytes in the concatenated image I flash.

(e.g. dd if=/dev/mtdX of=partitionX ; cat partiion1 partition2 partition3 | 
firmware.bin and then using the CFE flashimage command to tftp firmware.bin and 
write the flash after the CFE)

Should that work or will I likely have a problem with that approach?

Also, once I flash kamikaze, will the partitions be different (e.g. will there 
be a rootfs partition on an erase block boundary?) which would mean I couldn't 
just dd or mtd back the original firmware image?

TIA,

Daniel

-- 
And that's my crabbing done for the day.  Got it out of the way early, 
now I have the rest of the afternoon to sniff fragrant tea-roses or 
strangle cute bunnies or something.   -- Michael Devore
GnuPG Key Fingerprint 86 F5 81 A5 D4 2E 1F 1C      http://gnupg.org

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