why did my Boot0.bin got changed

[YveMag]

Hi

I m cleaning up my ssd and my nas
As i know, backup of nand can also be used as emunand
but to be sure its identical, i decided to diff my files

Before, lets see what I have done
I took my "clean" nand, put dongle inside, loaded payload and took a backup of my nand

as my microsd was to small for emunand and backup, i needed to shut down, move files
and i created emunand (not knowing i could have used the backup files by renaming the folder instead)

so, i put in my microsd, didnt knew this directly starts the switch, so i powered off
used dongle and payload,
created emunand

result
full.00.bin is little different between both system, ok result of accidently bootting ofw, before taking emunand
01-07, identical
boot1.bin identical

BUT

boot0.bin is different too

why did my bootfiles changed
nand backup => short moment of ofw after powerdown => emunand creation after ofw has run a few seconds


i thought boot files may get altered by autorcm, but i didnt checked this option, so i would expect, files dont change...

might this be a reason for some clean restored nand to get band after booting? ...a modified boot0.bin?
ok, i found the changed area is used for

NAND patrolling

whatever this means

 

[f00baR]

Hi

I m cleaning up my ssd and my nas
As i know, backup of nand can also be used as emunand
but to be sure its identical, i decided to diff my files

Before, lets see what I have done
I took my "clean" nand, put dongle inside, loaded payload and took a backup of my nand

as my microsd was to small for emunand and backup, i needed to shut down, move files
and i created emunand (not knowing i could have used the backup files by renaming the folder instead)

so, i put in my microsd, didnt knew this directly starts the switch, so i powered off
used dongle and payload,
created emunand

result
full.00.bin is little different between both system, ok result of accidently bootting ofw, before taking emunand
01-07, identical
boot1.bin identical

BUT

boot0.bin is different too

why did my bootfiles changed
nand backup => short moment of ofw after powerdown => emunand creation after ofw has run a few seconds


i thought boot files may get altered by autorcm, but i didnt checked this option, so i would expect, files dont change...

might this be a reason for some clean restored nand to get band after booting? ...a modified boot0.bin?
ok, i found the changed area is used for

NAND patrolling

whatever this means

Read this thread and you'll see why and what to do about it.
https://team-xecuter.com/community/threads/how-many-nand-dumps-does-it-take-to-be-sure-you-have-a-good-dump.128851/

 

[YveMag]

This answers no questions

But full0.bin got changed, due to the fact, i booted into ofw before creating the emunand

and boot0.bin is changhed at the postion of NAND patrolling (as stated in the wiki)
The issue, i cant find an explanation of nand patrolling feature

is it a pointer, are those fuses?

 

[MacD]

I think auto rcm alters alters it.

I'm not 100% sure though, but i can't see how it wouldn't.

I made sure to uninstall auto rcm before i made my backup, but after i had installed it, which i think therefore isn't a clean dump anyway.

But like i say, i don't know for sure.

 

[Hackerjac]

I think auto rcm alters alters it.

I'm not 100% sure though, but i can't see how it wouldn't.

I made sure to uninstall auto rcm before i made my backup, but after i had installed it, which i think therefore isn't a clean dump anyway.

But like i say, i don't know for sure.

You're right, AUTORCM is altering the Boot0