[BOOTLOADER] 2nd-bootloader for Custom ROMs on KFireHD 7" [06/24 CM12.1/TWRP 2.8.7.0]

Search This thread

Howard velasquez

New member
Jul 6, 2017
1
0
Introducing: Kindle Fire 2nd-bootloader + TWRP 2.8.x.x for the Kindle Fire HD 7

*** USE AT YOUR OWN RISK! WHILE I TRY MY BEST TO PROVIDE WORKING KERNELS/ROMS, I AM NOT RESPONSIBLE IF THIS SOFTWARE OR ANYTHING I'VE WORKED ON SUDDENLY FRIES YOUR DEVICE. ***

** THESE FILES WILL ONLY WORK ON A KINDLE FIRE HD 7 **

** WHEN MODDING THE KFIRE HD YOU SHOULD HAVE WORKING FASTBOOT DRIVERS/ACCESS ON YOUR PC. **


LOOKS LIKE NOT ALL FASTBOOT CABLES WILL AUTOMATICALLY PLACE YOU IN FASTBOOT MODE ON THE KINDLE FIRE HD 7. DOWNLOAD THE ANDROID SDK AND GO FROM THERE.
http://developer.android.com/sdk/index.html

Here's 1 website you can purchase a FASTBOOT adapter from (works with your normal USB cable)
http://shop.teamblackhat.info/Factory-Adapters-motadapt.htm
** I don't make any commission or fee from the sales of these devices, I just know they have them on stock most of the time and ship in a reasonable time frame unlike the Chinese variants found on ebay.

Q: How do I know if my fastboot works?
A: With the Kindle powered down, type the following command into a cmd/terminal window on your PC (should return with: < waiting for device> ):
fastboot -i 0x1949 getvar product

Then connect your fastboot cable to the Kindle and reboot. It *SHOULD* show a Fastboot screen and your terminal window should show something like:
product: Tate-XXX-XX (something here)

Type this to reboot out of fastboot mode:
fastboot -i 0x1949 reboot


** IF YOU HAVE QUESTIONS, RE-READ THROUGH THE THREAD FOR ANSWERS. WHEN YOU'RE ABSOLUTELY SURE NO ONE HAS ASKED YOUR QUESTION, GO AHEAD AND RE-READ THE THREAD AGAIN AND USE THE SEARCH FEATURE. THEN POST YOUR QUESTION IF YOU STILL CAN'T FIND THE ANSWER **



INSTRUCTIONS FOR INSTALLING A 2ND-BOOTLOADER TO LOAD CUSTOM KERNELS / ROMS / RECOVERY:
*** BE SURE YOU HAVE A GOOD CHARGE ON THE DEVICE ***

STEP 1. Backup your stock partitions to your own HD for later if you need disaster recovery:
Code:
adb shell su -c "dd if=/dev/block/mmcblk0boot0 of=/sdcard/boot0block.img"
adb shell su -c "dd if=/dev/block/platform/omap/omap_hsmmc.1/by-name/boot of=/sdcard/stock-boot.img"
adb shell su -c "dd if=/dev/block/platform/omap/omap_hsmmc.1/by-name/recovery of=/sdcard/stock-recovery.img"
adb shell su -c "dd if=/dev/block/platform/omap/omap_hsmmc.1/by-name/system of=/sdcard/stock-system.img" # This will take a few minutes
adb pull /sdcard/boot0block.img
adb pull /sdcard/stock-boot.img
adb pull /sdcard/stock-recovery.img
adb pull /sdcard/stock-system.img # This will take a few minutes
Take those files and put them somewhere safe.

**** MAC USERS MAY NEED TO SPARSE THE FILES FOR RE-FLASHING TO THE DEVICE. I NEED A MAC USER TO PROBABLY WORK THROUGH THAT PROCESS AND POST BACKUP COPIES OF THE STOCK PARTITIONS FOR DISASTER RECOVERY ****


STEP 2: Download the files you will need to install 2nd-bootloader, TWRP and CM:

ON THE FOLLOWING DEV-HOST LINKS
USE THE BLUE "DOWNLOAD NOW" BUTTON
-- DO NOT INSTALL AN EXECUTABLE DOWNLOADER TO YOUR SYSTEM! --
I'LL LOOK FOR A BETTER HOST WHEN I GET MORE TIME.

  1. Stack override file:
    Mirror 1: Download "stack" from Dev-Host
  2. [12/09] kfhd7-freedom-boot-7.4.6.img (USED ONLY THE FIRST TIME -- .zip files will have their own boot.img's from now on):
    Mirror 1: Download "kfhd7-freedom-boot-7.4.6.img" from Dev-Host
    md5sum: 1628fc4750d0d49cbce41ab616a9d732
  3. [06/24] TWRP 2.8.7.0 recovery flash Image:
    Mirror 1: Download TWRP from Dev-Host
  4. CM-12.1 for the Kindle Fire HD 7 (choose the latest version from):
    Mirror 1: Downloads CM
  5. Google Apps from Android File Host:
    https://www.androidfilehost.com/?w=files&flid=25361 (Use 5.1 version!)
  6. Download the older 7.2.3 bootloader file and flash to your device via fastboot:
    Mirror 1: Download bootloader from Dev-Host
    md5sum bb029673d8f186db4dff6d38f4aa28cf
    (You SHOULD check the md5sum before using fastboot -- downloads CAN be corrupted)
Place the CM-12.1 ROM and the gapps .zip on your device in the /sdcard area


STEP 3. Install the stack override in /system:
ADB commands entered while booted up into STOCK *rooted* Amazon Kindle OS -- May need to enable ADB debugging in Settings:
[2013-08-21] edited the location where stack is placed on device due to permissions changes
Code:
adb push stack /sdcard/
adb shell su -c "dd if=/sdcard/stack of=/dev/block/platform/omap/omap_hsmmc.1/by-name/system bs=6519488 seek=1"

STEP 4. Stop the auto recovery update script (this file may or may not be present):
Code:
adb shell su -c "mount -o remount,rw ext4 /system"
adb shell su -c "mv /system/etc/install-recovery.sh /system/etc/install-recovery.sh.bak"
adb shell su -c "mount -o remount,ro ext4 /system"


STEP 5:
[ With the device powered off: connect your FASTBOOT USB cable to the Kindle which should cause it to power on and enter "FASTBOOT" mode. Issue the following commands into your command/terminal window on your PC 1 at a time. ]

Code:
fastboot -i 0x1949 flash bootloader kfhd7-u-boot-prod-7.2.3.bin
fastboot -i 0x1949 flash boot kfhd7-freedom-boot-7.4.6.img
fastboot -i 0x1949 flash recovery kfhd7-twrp-2.8.7.0-recovery.img
fastboot -i 0x1949 reboot

*DONT RE-FLASH FREEDOM-BOOT.IMG LATER AFTER FLASHING CUSTOM ROMS -- IT'S FOR STOCK AMAZON OS ONLY / FIRST INSTALL ONLY*

** If everything was done correctly your Kindle will reboot and you will at first see the normal Kindle Fire ORANGE logo and then it will fade and come back as a BLUE logo. **

TO ENTER RECOVERY:
Press the left volume button (volume up) while the logo is still YELLOW and keep pressing until the logo turns BLUE. Wait a moment and you should enter recovery.


STEP 6:
CM-12.1 AND GAPPS INSTALLATION:
  • (OPTIONAL) Make a backup by selecting "Backup" and then slide your finger to the right on the "Swipe to Back Up"
  • Once complete use the pentagon "Home" icon in the lower left corner of the screen
  • Now, select "Wipe"
  • Swipe the "Swipe to Factory Reset"
  • Use the "Home" icon
  • Select "Install"
  • Browse to the location on your device where you saved the CM-12.1 / GAPPS .ZIP files
  • Select the CM12.1 ZIP file in the list by touching it, then confirm it says the name of the CM-12.1 .ZIP file on the next screen under "File to flash:"
  • Select "Add More Zips"
  • Select the GAPPS ZIP file in the list by touching it -- make sure it says the name of the .ZIP again under "File to flash:"
  • Swipe the "Swipe to Confirm Flash", and wait for it to finish.
  • If the screen is blank at any time you can hit the power button to "wake up" the device
  • Once the flash is done, you'll see a "Home" and "Reboot" buttons at the bottom of the screen
  • Select "Reboot"

CONGRATULATIONS YOU NOW HAVE THE ABILITY TO INSTALL CUSTOM KERNELS / RECOVERY AND ROMS.


FLASHING BACK TO STOCK:
** FIND THE FILES WE BACKED UP IN STEP #1: ** OR Follow this thread's instructions:
http://xdaforums.com/showthread.php?t=1951254

**** MAC USERS MAY NEED TO SPARSE THE FILES FOR RE-FLASHING TO THE DEVICE. I NEED A MAC USER TO PROBABLY WORK THROUGH THAT PROCESS AND POST BACKUP COPIES OF THE STOCK PARTITIONS FOR DISASTER RECOVERY ****

Plug in your fastboot cable and reboot so that you see the fastboot screen. On your computer go into a prompt and change to the directory where your stock backups are and enter the following commands:
Code:
fastboot -i 0x1949 flash boot [B]stock-boot.img[/B]
fastboot -i 0x1949 flash recovery [B]stock-recovery.img[/B]
fastboot -i 0x1949 flash system [B]stock-system.img[/B] # This one will take a few minutes
fastboot -i 0x1949 reboot


THANKS TO:
  • fattire for finding the original bootloader exploit
  • verygreen for doing some initial work on the 2nd-bootloader and fixing bugs (and letting me copy some of his bootloader installation instructions)

no puedo obtener acceso alos enlaces de descarga tengo una fire hd 7 2013 y no se como hacerla arrancar porfavor alguien que me ayude dejo mi correo howard-v2011@hotmail.com
espero alguien pueda ayudarme tengo una semana intentando
 

sd_shadow

Recognized Contributor / XDA Welcome Team
Sep 21, 2011
18,972
2
9,989
South Dakota
goo.gl
Motorola Droid X
Amazon Fire
no puedo obtener acceso alos enlaces de descarga tengo una fire hd 7 2013 y no se como hacerla arrancar porfavor alguien que me ayude dejo mi correo howard-v2011@hotmail.com
espero alguien pueda ayudarme tengo una semana intentando

"I can not get access to the download links I have a fire hd 7 2013 and I do not know how to make it boot please someone help me leave my email howard-v2011@hotmail.com
I hope someone can help me I have a week trying"

English only on XDA please
Don't quote post#1, it's unnecessary and a waste of space

---------- Post added at 10:32 PM ---------- Previous post was at 10:31 PM ----------

See link in
https://xdaforums.com/showpost.php?p=71286971&postcount=672
 
  • Like
Reactions: dingers1

dingers1

New member
Feb 23, 2017
2
0
All working great but internal memory low.

Hi,
Great guidance notes..........working fine with known cliches, camera out.
However, receiving warnings over memory low upon completion but managed to regain about 1 gb Investigation shows 85%used of internal memory. Its a 16 gb unit. Is this usual, can I reduce this and how?

Is the second boot loader relative to the Android and does the primary boot area hold the original Kindle Fire HD stuff?

All interesting stuff for my old grey cells.

Thank you for any help! :good:

dingers1
 

dingers1

New member
Feb 23, 2017
2
0
All working great but internal memory low

HI,

Solved...... didn't clear files downloaded.:(

Great forum.

dingers1 :good:
 

Cock-Punisher

Member
Mar 14, 2015
22
3
I'm stuck on blue logo. Need some help.
I can go into twrp and flash Roms, but after reboot I am stuck on blue logo after seeing the orange for a short time. I don't have an idea what I did wrong. Followed the steps.
 
So I made a mistake. After 2 years of not using my Kindle, I decided to flash crDroid today and everything was working great. Not remembering how I originally installed TWRP, I decided to flash Magisk, obviously this was the mistake. Magisk overwrote my boot img which removed boot 2. Now I'm stuck at the orange Kindle fire logo since boot 2 is gone and I'm not sure how to proceed. Does anybody have any advice?
 

mrkhigh

Senior Member
Dec 6, 2012
1,879
608
Google Pixel 2
Google Pixel 3
So I made a mistake. After 2 years of not using my Kindle, I decided to flash crDroid today and everything was working great. Not remembering how I originally installed TWRP, I decided to flash Magisk, obviously this was the mistake. Magisk overwrote my boot img which removed boot 2. Now I'm stuck at the orange Kindle fire logo since boot 2 is gone and I'm not sure how to proceed. Does anybody have any advice?
I've been out of the game longer than you..
But.... See if you can access adb, then fastboot, then reflash

If you do not have adb, You'll have to use a fast boot cable.

Good luck, the device may be older than the value of effort You'll put into this.
 
  • Like
Reactions: sd_shadow
I've been out of the game longer than you..
But.... See if you can access adb, then fastboot, then reflash

If you do not have adb, You'll have to use a fast boot cable.

Good luck, the device may be older than the value of effort You'll put into this.

From what I can gather from the OP, once I get it into fastboot mode I need to flash things in Step 5. Now the question is, do I flash the freedom boot img or not? OP says that is not needed if already on a custom ROM, which I was, but I'm thinking I need to flash it to be able to access TWRP. What do you think?
 

zeddev

Member
Sep 11, 2018
29
1
One of the FAQ pages says that the exploit allowing 2nd recovery installation and non standard recovery images has been fixed and this will now hard brick the device.

If that is right , there should be a BIG RED LETTER WARNING at the top of this thread.
 

Sword900

Member
Dec 1, 2013
43
28
So I made a mistake. After 2 years of not using my Kindle, I decided to flash crDroid today and everything was working great. Not remembering how I originally installed TWRP, I decided to flash Magisk, obviously this was the mistake. Magisk overwrote my boot img which removed boot 2. Now I'm stuck at the orange Kindle fire logo since boot 2 is gone and I'm not sure how to proceed. Does anybody have any advice?
So, have you solved this problem? I made same mistake installing Magisk...
 

TidusWulf

Senior Member
Sep 21, 2010
297
26
Seattle, WA
Seems liek in fastboot the -i is depreciated. I am able to enter fastboot (via terminal on the tablet) but I don't know how to do next steps to get a second bootloader. I'm hoping to put TWRP and a custom ROM on this, but I'm stuck on the step after entering fastboot. I also have a TATE-PVT-08 unkown device in my device manager, if that's part of the issue.

this is with the D025 serial Kindle Fire HD 7 btw.
 

sd_shadow

Recognized Contributor / XDA Welcome Team
Sep 21, 2011
18,972
2
9,989
South Dakota
goo.gl
Motorola Droid X
Amazon Fire
Seems liek in fastboot the -i is depreciated. I am able to enter fastboot (via terminal on the tablet) but I don't know how to do next steps to get a second bootloader. I'm hoping to put TWRP and a custom ROM on this, but I'm stuck on the step after entering fastboot. I also have a TATE-PVT-08 unkown device in my device manager, if that's part of the issue.

this is with the D025 serial Kindle Fire HD 7 btw.
Sounds like you don't have the correct driver installed or you need to select correct driver in device manager.

Sent from my perry_f using XDA Labs
 

boortok

Member
Nov 27, 2020
12
0
KIndle fire hd7 tate 2nd gen done all the flashing twrp 2.8.7.0 etc and when I reboot out of fastboot it goes into bootloop yellow kindle logo and then fastboot kindle fire logo then screen goes black and I can hear kindle connecting and dissconecting over and over....I have tried holding power down for 20 seconds etc then power on again but same bootloop...I can not boot into twrp as it never goes to blue log...thanks
sorry if I double posted not sure where I should ask
 
Hello!
The link above from the instructions does not work any longer.
Any idea from where to get the stack-file?
Thank you! :)
i found it on AFH. most dead links you can find the app/software there.https://androidfilehost.com/?fid=24052804347764445e thisd helps. and good luck and safe rooting.
 
  • Like
Reactions: sd_shadow

Balya

New member
Apr 26, 2011
1
0
Unfortunately, the links no longer work. Where can I download these files?
 

Top Liked Posts

  • There are no posts matching your filters.
  • 122
    [BOOTLOADER] 2nd-bootloader for Custom ROMs on KFireHD 7" [06/24 CM12.1/TWRP 2.8.7.0]

    Introducing: Kindle Fire 2nd-bootloader + TWRP 2.8.x.x for the Kindle Fire HD 7

    *** USE AT YOUR OWN RISK! WHILE I TRY MY BEST TO PROVIDE WORKING KERNELS/ROMS, I AM NOT RESPONSIBLE IF THIS SOFTWARE OR ANYTHING I'VE WORKED ON SUDDENLY FRIES YOUR DEVICE. ***

    ** THESE FILES WILL ONLY WORK ON A KINDLE FIRE HD 7 **

    ** WHEN MODDING THE KFIRE HD YOU SHOULD HAVE WORKING FASTBOOT DRIVERS/ACCESS ON YOUR PC. **


    LOOKS LIKE NOT ALL FASTBOOT CABLES WILL AUTOMATICALLY PLACE YOU IN FASTBOOT MODE ON THE KINDLE FIRE HD 7. DOWNLOAD THE ANDROID SDK AND GO FROM THERE.
    http://developer.android.com/sdk/index.html

    Here's 1 website you can purchase a FASTBOOT adapter from (works with your normal USB cable)
    http://shop.teamblackhat.info/Factory-Adapters-motadapt.htm
    ** I don't make any commission or fee from the sales of these devices, I just know they have them on stock most of the time and ship in a reasonable time frame unlike the Chinese variants found on ebay.

    Q: How do I know if my fastboot works?
    A: With the Kindle powered down, type the following command into a cmd/terminal window on your PC (should return with: < waiting for device> ):
    fastboot -i 0x1949 getvar product

    Then connect your fastboot cable to the Kindle and reboot. It *SHOULD* show a Fastboot screen and your terminal window should show something like:
    product: Tate-XXX-XX (something here)

    Type this to reboot out of fastboot mode:
    fastboot -i 0x1949 reboot


    ** IF YOU HAVE QUESTIONS, RE-READ THROUGH THE THREAD FOR ANSWERS. WHEN YOU'RE ABSOLUTELY SURE NO ONE HAS ASKED YOUR QUESTION, GO AHEAD AND RE-READ THE THREAD AGAIN AND USE THE SEARCH FEATURE. THEN POST YOUR QUESTION IF YOU STILL CAN'T FIND THE ANSWER **



    INSTRUCTIONS FOR INSTALLING A 2ND-BOOTLOADER TO LOAD CUSTOM KERNELS / ROMS / RECOVERY:
    *** BE SURE YOU HAVE A GOOD CHARGE ON THE DEVICE ***

    STEP 1. Backup your stock partitions to your own HD for later if you need disaster recovery:
    Code:
    adb shell su -c "dd if=/dev/block/mmcblk0boot0 of=/sdcard/boot0block.img"
    adb shell su -c "dd if=/dev/block/platform/omap/omap_hsmmc.1/by-name/boot of=/sdcard/stock-boot.img"
    adb shell su -c "dd if=/dev/block/platform/omap/omap_hsmmc.1/by-name/recovery of=/sdcard/stock-recovery.img"
    adb shell su -c "dd if=/dev/block/platform/omap/omap_hsmmc.1/by-name/system of=/sdcard/stock-system.img" # This will take a few minutes
    adb pull /sdcard/boot0block.img
    adb pull /sdcard/stock-boot.img
    adb pull /sdcard/stock-recovery.img
    adb pull /sdcard/stock-system.img # This will take a few minutes
    Take those files and put them somewhere safe.

    **** MAC USERS MAY NEED TO SPARSE THE FILES FOR RE-FLASHING TO THE DEVICE. I NEED A MAC USER TO PROBABLY WORK THROUGH THAT PROCESS AND POST BACKUP COPIES OF THE STOCK PARTITIONS FOR DISASTER RECOVERY ****


    STEP 2: Download the files you will need to install 2nd-bootloader, TWRP and CM:

    ON THE FOLLOWING DEV-HOST LINKS
    USE THE BLUE "DOWNLOAD NOW" BUTTON
    -- DO NOT INSTALL AN EXECUTABLE DOWNLOADER TO YOUR SYSTEM! --
    I'LL LOOK FOR A BETTER HOST WHEN I GET MORE TIME.

    1. Stack override file:
      Mirror 1: Download "stack" from Dev-Host
    2. [12/09] kfhd7-freedom-boot-7.4.6.img (USED ONLY THE FIRST TIME -- .zip files will have their own boot.img's from now on):
      Mirror 1: Download "kfhd7-freedom-boot-7.4.6.img" from Dev-Host
      md5sum: 1628fc4750d0d49cbce41ab616a9d732
    3. [06/24] TWRP 2.8.7.0 recovery flash Image:
      Mirror 1: Download TWRP from Dev-Host
    4. CM-12.1 for the Kindle Fire HD 7 (choose the latest version from):
      Mirror 1: Downloads CM
    5. Google Apps from Android File Host:
      https://www.androidfilehost.com/?w=files&flid=25361 (Use 5.1 version!)
    6. Download the older 7.2.3 bootloader file and flash to your device via fastboot:
      Mirror 1: Download bootloader from Dev-Host
      md5sum bb029673d8f186db4dff6d38f4aa28cf
      (You SHOULD check the md5sum before using fastboot -- downloads CAN be corrupted)
    Place the CM-12.1 ROM and the gapps .zip on your device in the /sdcard area


    STEP 3. Install the stack override in /system:
    ADB commands entered while booted up into STOCK *rooted* Amazon Kindle OS -- May need to enable ADB debugging in Settings:
    [2013-08-21] edited the location where stack is placed on device due to permissions changes
    Code:
    adb push stack /sdcard/
    adb shell su -c "dd if=/sdcard/stack of=/dev/block/platform/omap/omap_hsmmc.1/by-name/system bs=6519488 seek=1"

    STEP 4. Stop the auto recovery update script (this file may or may not be present):
    Code:
    adb shell su -c "mount -o remount,rw ext4 /system"
    adb shell su -c "mv /system/etc/install-recovery.sh /system/etc/install-recovery.sh.bak"
    adb shell su -c "mount -o remount,ro ext4 /system"


    STEP 5:
    [ With the device powered off: connect your FASTBOOT USB cable to the Kindle which should cause it to power on and enter "FASTBOOT" mode. Issue the following commands into your command/terminal window on your PC 1 at a time. ]

    Code:
    fastboot -i 0x1949 flash bootloader kfhd7-u-boot-prod-7.2.3.bin
    fastboot -i 0x1949 flash boot kfhd7-freedom-boot-7.4.6.img
    fastboot -i 0x1949 flash recovery kfhd7-twrp-2.8.7.0-recovery.img
    fastboot -i 0x1949 reboot

    *DONT RE-FLASH FREEDOM-BOOT.IMG LATER AFTER FLASHING CUSTOM ROMS -- IT'S FOR STOCK AMAZON OS ONLY / FIRST INSTALL ONLY*

    ** If everything was done correctly your Kindle will reboot and you will at first see the normal Kindle Fire ORANGE logo and then it will fade and come back as a BLUE logo. **

    TO ENTER RECOVERY:
    Press the left volume button (volume up) while the logo is still YELLOW and keep pressing until the logo turns BLUE. Wait a moment and you should enter recovery.


    STEP 6:
    CM-12.1 AND GAPPS INSTALLATION:
    • (OPTIONAL) Make a backup by selecting "Backup" and then slide your finger to the right on the "Swipe to Back Up"
    • Once complete use the pentagon "Home" icon in the lower left corner of the screen
    • Now, select "Wipe"
    • Swipe the "Swipe to Factory Reset"
    • Use the "Home" icon
    • Select "Install"
    • Browse to the location on your device where you saved the CM-12.1 / GAPPS .ZIP files
    • Select the CM12.1 ZIP file in the list by touching it, then confirm it says the name of the CM-12.1 .ZIP file on the next screen under "File to flash:"
    • Select "Add More Zips"
    • Select the GAPPS ZIP file in the list by touching it -- make sure it says the name of the .ZIP again under "File to flash:"
    • Swipe the "Swipe to Confirm Flash", and wait for it to finish.
    • If the screen is blank at any time you can hit the power button to "wake up" the device
    • Once the flash is done, you'll see a "Home" and "Reboot" buttons at the bottom of the screen
    • Select "Reboot"

    CONGRATULATIONS YOU NOW HAVE THE ABILITY TO INSTALL CUSTOM KERNELS / RECOVERY AND ROMS.


    FLASHING BACK TO STOCK:
    ** FIND THE FILES WE BACKED UP IN STEP #1: ** OR Follow this thread's instructions:
    http://xdaforums.com/showthread.php?t=1951254

    **** MAC USERS MAY NEED TO SPARSE THE FILES FOR RE-FLASHING TO THE DEVICE. I NEED A MAC USER TO PROBABLY WORK THROUGH THAT PROCESS AND POST BACKUP COPIES OF THE STOCK PARTITIONS FOR DISASTER RECOVERY ****

    Plug in your fastboot cable and reboot so that you see the fastboot screen. On your computer go into a prompt and change to the directory where your stock backups are and enter the following commands:
    Code:
    fastboot -i 0x1949 flash boot [B]stock-boot.img[/B]
    fastboot -i 0x1949 flash recovery [B]stock-recovery.img[/B]
    fastboot -i 0x1949 flash system [B]stock-system.img[/B] # This one will take a few minutes
    fastboot -i 0x1949 reboot


    THANKS TO:
    • fattire for finding the original bootloader exploit
    • verygreen for doing some initial work on the 2nd-bootloader and fixing bugs (and letting me copy some of his bootloader installation instructions)
    13
    Changelog: updated 2013-07-08

    freedom boot.img (for use w/ stock Amazon OS + 2nd-bootloader):
    • [07/08] Updated w/ kernel from 7.4.3 release

    Amazon OS .zip:
    • [07/08] Rebuilt on version 7.4.3 from Amazon

    TeamWin Recovery (TWRP) 2.6.0.0

    • [*][07/08] USB Vendor ID / Product ID in recovery now matches stock Amazon OS
    • [07/08] Fixed long pause before recovery entry
    • [07/08] Based on 7.4.3 stock kernel
    • [07/08] Fixed recovery bootloop issue
    • [07/08] Screen timeout feature currently disabled due to screen blanking bug
    • [07/08] TWRP 2.6.0.0 update
    • [07/08] Added "EFS" partition backup option. Normally, don't need to make too many backups of this, but having a backup will enable you to recover HDMI keys, and some other data.
    6
    I added a STEP 6 which is optional but recommended:

    Because we had to drop a 4K file right in the middle of the operating system, there is a chance that we've killed a binary that is used by the OS. As a final "cleanup" step to installing the bootloader, I recommend everyone re-flash the OS to /system. The stack space is pre-allocated during this process so that the files going back onto the /system partition will NOT land on it anymore.

    Download a flashable Amazon OS ROM (7.2.3): Amazon OS 7.2.3: http://goo.im/devs/Hashcode/tate/kfhd7-amazon-os-7.2.3.zip Place this in the /sdcard

    This is the stock Amazon OS which is rooted, has Superuser.apk and busybox. (Users can use this as an easy means of going back to stock the easy way via recovery. It also includes the modified boot.img including the 2nd-bootloader).

    INSTALL THE .ZIP IN TWRP:
    • Select "Install"
    • Use the file manager to browse and click on the "kfhd7-amazon-os-7.2.3.zip" file.
    • Swipe to start.
    • Once that's done, reboot.

    NOTE: Once we start using Jellybean ROMS, the location of "sdcard" can move and to find this file you may need to go "Up a level" to find "data" and then "media" and look for it in there.
    4
    Re: [BOOTLOADER] Install 2nd-bootloader for Custom ROMs on KFireHD 7"

    Can I use install this and still use stock os?

    Sent from my KFTT using XDA Premium HD app

    Yes, that's how the initial install is setup.

    Sent from my DROID RAZR HD using Tapatalk 2
    4
    Re: [BOOTLOADER] Install 2nd-bootloader for Custom ROMs on KFireHD 7"

    Whenever I get around to installing ubuntu or linux on my 2nd hard drive I plan on downloading the sdk, gonna start to try and learn a thing or 2 in the world of android development :D

    Edit: hey hashcode, i just noticed twrp recovery was updated to 2.4, can i just flash it thru fastboot? Or does it need to be modified for the HD7?

    Sent from my KFTT using Tapatalk HD

    The custom recovery and kernels we use on the new Kindle Fires require special modifications or they will break on Amazons signature check.

    I can build a new recovery with the 2.4 update over the next few days. It will probably come in 2 forms:
    - an updated image file for use during the 2nd bootloader installation
    - a flash .zip update for those who are already running custom recovery.

    Sent from my DROID RAZR HD using Tapatalk 2