Page locked

This page is currently locked for editing by another user. You have to wait until this user finishes editing or the lock expires.
Currently locked by: 10.89.1.3,18.216.171.199
Lock expires at: 2025/05/10 22:49 (9 min)
This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
Repartition Internal Storage

In the latest kernel the tegra partition tables are supported. No need to alter the table the complicated way.


BACKUP EVERY PARTITION AND THE PARTITION TABLE

Altering the layout of the storage is a really intrusive thing and might lead to point of no return. If you are not sure what to do or how to do it in detail go on and ask before you flash it or let it be.
All values from files and in commands are specific to my device and actions, which is also true for generalized values.


IF ANYTHING GOES WRONG:
nvflash --bct orginal.bct --setbct --configfile cfg/real.cfg --bl fastboot.bin --go
nvflash --resume ...

Note that you need the orginal.bct and real.cfg therefor

Step 1: Prepare the files

real.cfg (attached, see links below)
IMPORTANT you need it for resetting partition table to factory but if you have the partition table you can create it afterwards

retrieve the partition table with nvflash
you can use my real.cfg as a sample for AC100-10V
alter the section size ( in bytes ) according to your layout and size

altered.cfg (attached), layout recommendations
change real.cfg according to your needs and save it under a new name
I would highly recommendto keep the partitions BCT, PT, EBT in size and start point since at least EBT seems to be the hardcoded bootloader section and cannot be altered at the moment
if you experience something different let everyone know
in my case I sacrificed SOS as a place for my new MBR (see my altered.cfg) be aware that you cannot "dual boot" with this layout
another fixed point is the position of LNX although you can alter its size
as you can see in my altered.cfg I chose to name my big partition RT and kept it as last you can add partitions as you like here
be aware that the sizes are multiples of 2048

change type of partition 4 (EBT) in altered.cfg
[partition]
name=EBT
id=4
type=data
...

be warnedthis part may seem strange since you expect a valid layout to contain a bootloader but with a bootloader section nvflash will fail hence you will never be able to write a layout with a type=bootloader section to the device

copy fastboot.stock.bin from the directory prebuilt to nvflash und ther new name fastboot.bin that it can be send with the --create command wheere it is needed for the filename=fastboot.bin part of EBT
since in every sample file of L4T I found this part I decided to keep it in my aswell
TODO test if it is possible to send other backup files directly with --create to be more efficient and have a proper verification


fastboot.bin
nvflash will require fastboot.bin in current folder, so copy it from linux4tegra/prebuid like that:
[root@pc nvflash]# ln -s../prebuilt/fastboot.stock.bin ./fastboot.bin
orginal.bct
the orginal bct file is the first 4080bytes of Partition 2
dd if=backup_part-2.img bs=1 count=4080 of=orginal.bct

I noticed that with hexdump -C original.bct everytime the second line ( offset 0x20 ) has to star like '01 00 02 00' which seems a good point of verification

Step 2: creating the new partition
IMPORTANT since this alters the partition table it could really mess everything up so be warned
make sure you have backups of every partition AND a partition table

double check and execute
./nvflash --bct orginal.bct --setbct --bl fastboot.bin --configfile altered.cfg --create --verifypart -1 --go

OUTPUT is like that:

Nvflash started
rcm version 0X20001
System Information:
chip name: t20
chip id: 0x20 major: 1 minor: 2
chip sku: 0x8
chip uid: 0x161c10c4432132d7
macrovision: disabled
hdcp: enabled
sbk burned: false
dk burned: false
boot device: emmc
operating mode: 3
device config strap: 1
device config fuse: 0
sdram config strap: 1

sending file: orginal.bct
- 4080/4080 bytes sent
orginal.bct sent successfully
downloading bootloader -- load address: 0x108000 entry point: 0x108000
sending file: fastboot.bin
| 931920/931920 bytes sent
fastboot.bin sent successfully
waiting for bootloader to initialize
bootloader downloaded successfully
setting device: 2 3
creating partition: BCT
creating partition: PT
creating partition: EBT
creating partition: MBR
creating partition: LNX
creating partition: RT
Formatting partition 2 BCT please wait.. done!
Formatting partition 3 PT please wait.. done!
Formatting partition 4 EBT please wait.. done!
Formatting partition 7 MBR please wait.. done!
Formatting partition 6 LNX please wait.. done!
Formatting partition 8 RT please wait.. done!
done!
Enabling verification for partition ID = 4...
sending file: fastboot.bin
| 931920/931920 bytes sent
fastboot.bin sent successfully
Verifying partition ID = 4...Please wait!!
Verification successful!!
VERIFICATION COMPLETE....

Step 3: I altered it and now?

first I would get the new partition table with --getpartitiontable take a look at it and compare it to your original partition table
BCT, PT, EBT must not be altered and LNX should start at the same offset
after that back it up
the next step was always for me to restore partition-4 ( EBT ) back to the device

after that you can turn on your device it should show you the familiar Toshiba Logo
if it doesn't something is wrong with either your layout ( BCT, PT, EBT altered?) or the rewriting of the bootloader
the worst experience I had was ./nvflash --bl fastboot.bin ... being rejected after a --create because of a faulty bootloader section ( see "If anything goes wrong" )
install a distro but keep in mind:
you have to alter the kernel image you write to LNX:
Alter the commandline
my original was '... tegrapart=recovery:300:a00:800,boot:d00:1000:800,mbr:1d00:200:800,system:1f00:10032964:800'
I altered to the following 'tegrapart=mbr:300:a00:800,boot:d00:8000,system:8d00:3b0b00'
scheme explained name:offset:length:blocksize
IMPORTANT: in linux you will only see everything after mbr imho if you choose a wrong location here I assume linux will just write there
as you can see my cmd line now starts with the mbr because it is the first partition for me after EBT ( I sacrificed SOS for it )
the offset 0x300 is for the first partition after EBT I havn't changed that
I kept the size of 0xa00 for MBR that LNX can start at its good old position but as you can see I grew LNX to the size of 0x8000
the last part is RT my big root partition with the calculated values ( boot offset + boot length == system offset ... )
as you can see I have two devices after MBR (LNX==boot and RT==system) which will show up in linx as /dev/mmcblk0p1 and mmcblk0p2
Alter the initrd
if something gets mounted e. g. in init you may have to change the device name
create a kernel image with those changes and hopefully