Possible Issue with en751221tool

[digitalentropy]

I am trying to backup flash from an EN7628 using en751221tool.py, but running to a bunch challenges.

1. The readme and script itself seem to keep making reference to a "readflash" command that does not seem to exist within the bootloader nor does it seem to do anything.

2. It's unclear what the guidelines are for how to define start address or length of dump. The example in the python script is not particularly clear why everything starts at 0x80020000.

This is the result of the "mtd" command when run from the bootloader:

0x00000000-0x00200000 : "bootloader" 0x00200000-0x00400000 : "dsd" 0x00400000-0x00675cc2 : "kernel" 0x00675cc2-0x01be5cc2 : "rootfs" 0x00400000-0x04400000 : "tclinux" 0x04400000-0x04675d6f : "kernel_slave" 0x04675d6f-0x05c05d6f : "rootfs_slave" 0x04400000-0x08400000 : "tclinux_slave" 0x08400000-0x1c400000 : "system" 0x1c400000-0x1c600000 : "uenv" 0x1d5c0000-0x1d740000 : "art"

The NAND is a 4Gbit chip with ID MXIC35LF4GE4AD and detected flash size of 0x20000000. Do you have any guidance on what to modify or change to dump the flash?

[danitool]

Hi @digitalentropy

1. The readme and script itself seem to keep making reference to a "readflash" command that does not seem to exist within the bootloader nor does it seem to do anything.

If your bootloader doesn't have the readflash command then might be impossible to dump the flash chip.

2. It's unclear what the guidelines are for how to define start address or length of dump. The example in the python script is not particularly clear why everything starts at 0x80020000.

0x80020000 it's a RAM address where we can safely copy the flash chip, before dumping it with the python script

Do you have any guidance on what to modify or change to dump the flash?

Unfortunatelly I don't have any longer a router with this en751221 CPU. If there are more ways to dump the flash I have no idea right now.

Regards.

[digitalentropy]

Thanks for the responses, they were helpful.

So the purpose of the readflash command was to load flash memory into memory address space that we can then use the dump command with? The dump command does seem to exist, and seems to dump memory of some addresses, but it's unclear what the bounds of "safe" memory are.