[Windows RT Development and Hacking] Thedarkwolf123:
With a lot of work scrounging around, I've found all the pieces that fit making a jail-broken OS boot-ready Surface RT. As of Now like 5 or 6 years after it's release, there still doesn't seem to be a OS prepared to run on the Surface RT, but maybe if this thread gets enough popularity someone can get an android OS (Possibly derived from an Asus TF502T) Or a debian style Linux build for it. Credit to [MENTION=2022267]ShapeShifter499[/MENTION] for secure boot unlock, [MENTION=224595]mamaich[/MENTION] for Hard drive repartition instructions, [MENTION=5561472]Screeny[/MENTION] for original Downgrade instructions, and [MENTION=1854527]netham45[/MENTION] for jailbreak tool and I have posted links to other threads that will also help once 8.1 is downgraded and jailbroken. Here are all files shared and ready for you:

https://drive.google.com/drive/folders/12VilYYz-gF82qzzs6qOkUXoaKz2us8J9?usp=sharing

And Here goes the instructions for the boot-ready Surface RT

1. Create Recovery usb stick (search for recovery drive in control panel, not the file recovery(you might want that too though))

2. Download Surface RT 8.0 Recovery (Took me forever to find, microsoft has removed it from it's site, i have included)

3. Unzip and Copy the file "install.wim" (located under "sources" from your downloaded 8.0 recovery image) to the root of your 8.1 recovery USB stick

4. Reboot into Recovery with the 8.1 recovery stick.

5. Open Command Prompt

6. Use DiskPart to clean the whole Disk (I had to use the override command)

7. While in Disk part use the following commands- (Minus the rem parts)

convert gpt

rem === 1. Windows RE tools partition ===========

create partition primary size=350

format quick fs=ntfs label="WinRE"

set id="de94bba4-06d1-4d40-a16a-bfd50179d6ac"

assign letter="T"

gpt attributes=0x8000000000000001

rem === 2. System partition =====================

create partition efi size=200

rem *** NOTE: For 4KB-per-sector drives, change this value to 260

format quick fs=fat32 label="System"

assign letter="S"

rem === 3. Microsoft Reserved (MSR) partition ===

create partition msr size=128

rem === 4. Windows partition ====================

rem == a. Create Windows partition ===========

create partition primary

rem == b. Create space for recovery image ====

shrink minimum=3600

rem == c. Prepare the Windows partition ======

format quick fs=ntfs label="Windows"

assign letter="W"

rem === 5. Recovery image partition =============

create partition primary

format quick fs=ntfs label="Recovery Image"

set id="de94bba4-06d1-4d40-a16a-bfd50179d6ac"

assign letter="R"

gpt attributes=0x8000000000000001

exit

8. While in Command Prompt do the following

Dism /apply-image /imagefile: U:\Install.Wim /index:1 /ApplyDir:W:\

(Make sure to include spaces in the proper places and replace U with your Recovery Drive letter, can be found with Diskpart command 'list vol')

bootrec /fixboot

9. Restart, login and disable automatic updates

10. Disable Bitlocker with administative command prompt with the following

manage-bde -unlock C: -RecoveryPassword YOUR-BITLOCKER-RECOVERY-KEY-HERE (Find your bitlocker code it has changed)

manage-bde -off C:

11. get the secureboot file and run the cmd file as admin. (use volume keys and windows button to select accept when the time comes)

12. After reboot (If stuck in bitlocker bootloop use recovery cmd to do #10) run administrative cmd and use- bcdedit /set {default} testsigning on && bcdedit /set {bootmgr} testsigning on

13. Use RT_jailbreak in administrative mode to run unsigned apps

14. Use SignTool to Sign any apps you want to continue to run

(optional)

15. use [MENTION=7009241]VNNGYN[/MENTION] development tool to continue updates and remove infected updates

I am Soon to test whether i can update directly from final state at #14 to windows 8.1 using the update file and development tool given without ruining anything noticable (Probably safer to run through all updates naturally but I'm impatient), will update with details as soon as I am successful.
---Update---- Microsoft seems to force going through the whole update process so no direct updating to 8.1------

Hopefully people can get the ball rolling with some other OS working fully on this tablet unlike windows 10 iot flop.

Development tool: https://xdaforums.com/windows-8-rt/rt-development/windows-8-1-rt-jailbreak-exploit-t3226835

Hacked Desktop Apps: https://xdaforums.com/showthread.php?t=2092348

Compiling guide: https://xdaforums.com/showthread.php?t=2096820

One Desktop app store: https://xdaforums.com/showthread.php?t=2559750

Another Desktop app store: https://xdaforums.com/showthread.php?t=2546221

I apologize if there's anything I missed, these are the same steps I took and where I'm at, once an OS development becomes available I will update a reserved comment.