[Fire HD 8 and HD 10 Original Android Development] lilsphinx90:
So, I'm booted on the fireiso now.

[root@sysresccd /run/media/root/New 2TB Drive/Downloads/amonet]# sudo ./bootrom-step.sh
[2019-10-17 00:58:38.947727] Waiting for bootrom
[2019-10-17 00:59:03.815124] Found port = /dev/ttyACM0
[2019-10-17 00:59:03.815623] Handshake

* * * If you have a short attached, remove it now * * *
* * * Press Enter to continue * * *

[2019-10-17 00:59:05.820052] Init crypto engine
[2019-10-17 00:59:05.842331] Disable caches
[2019-10-17 00:59:05.843543] Disable bootrom range checks
[2019-10-17 00:59:05.859430] Load payload from ../brom-payload/build/payload.bin = 0x4888 bytes
[2019-10-17 00:59:05.867335] Send payload
[2019-10-17 00:59:06.543794] Let's rock
[2019-10-17 00:59:06.545134] Wait for the payload to come online...
[2019-10-17 00:59:07.684057] all good
[2019-10-17 00:59:07.685963] Check GPT
[2019-10-17 00:59:08.064339]
[2019-10-17 00:59:08.065712] Sector size (logical): 512 bytes
[2019-10-17 00:59:08.066500] Disk identifier (GUID): BE9E3536-6B98-4084-A368-36B21A533077
[2019-10-17 00:59:08.066979] Partition table holds up to 128 entries
[2019-10-17 00:59:08.067415] This partition table begins at sector 2 and ends at sector 33
[2019-10-17 00:59:08.067884] First usable sector is 34, last usable sector is 30777310
[2019-10-17 00:59:08.068398] Other partition table is at sector 30777343
[2019-10-17 00:59:08.068803]
[2019-10-17 00:59:08.069293] Number Start (sector) End (sector) Size Name
[2019-10-17 00:59:08.071055] 1 1024 7167 3.00 MiB proinfo
[2019-10-17 00:59:08.072039] 2 7168 16383 4.50 MiB PMT
[2019-10-17 00:59:08.073049] 3 16384 17407 512.00 KiB lk
[2019-10-17 00:59:08.073995] 4 17408 18431 512.00 KiB lk2
[2019-10-17 00:59:08.075114] 5 18432 51199 16.00 MiB boot_x
[2019-10-17 00:59:08.075998] 6 51200 86015 17.00 MiB recovery_x
[2019-10-17 00:59:08.076859] 7 86016 96255 5.00 MiB tee1
[2019-10-17 00:59:08.077984] 8 96256 106495 5.00 MiB tee2
[2019-10-17 00:59:08.078955] 9 106496 187391 39.50 MiB metadata
[2019-10-17 00:59:08.080027] 10 187392 189439 1024.00 KiB kb
[2019-10-17 00:59:08.081120] 11 189440 191487 1024.00 KiB dkb
[2019-10-17 00:59:08.082005] 12 191488 192511 512.00 KiB MISC
[2019-10-17 00:59:08.082909] 13 192512 208895 8.00 MiB reserved
[2019-10-17 00:59:08.083776] 14 208896 3515391 1.58 GiB system
[2019-10-17 00:59:08.084649] 15 3515392 4383743 424.00 MiB cache
[2019-10-17 00:59:08.085510] 16 4383744 30084095 12.25 GiB userdata
[2019-10-17 00:59:08.086373] 17 30084096 30309375 110.00 MiB boot
[2019-10-17 00:59:08.087212] 18 30309376 30777310 228.48 MiB recovery
[2019-10-17 00:59:08.111677]
[2019-10-17 00:59:08.112129] Check boot0
[2019-10-17 00:59:08.353988] Check rpmb
[2019-10-17 00:59:08.564184] Clear preloader header
[8 / 8]
[2019-10-17 00:59:08.980927] Downgrade rpmb
[2019-10-17 00:59:08.983982] Recheck rpmb
[2019-10-17 00:59:09.878524] rpmb downgrade ok
[2019-10-17 00:59:09.880239] Flash preloader
[272 / 272]
[272 / 272]
[2019-10-17 00:59:22.091426] Flash tz
[6459 / 6459]
[2019-10-17 01:01:40.808788] Flash lk
[950 / 950]
[2019-10-17 01:02:01.449809] Inject payload
[8 / 8]
[962 / 962]
[8 / 8]
[962 / 962]
[2019-10-17 01:02:43.581469] Force fastboot
[2019-10-17 01:02:43.891682] Flash preloader header
[4 / 4]
[4 / 4]
[2019-10-17 01:02:44.310679] Reboot
[root@sysresccd /run/media/root/New 2TB Drive/Downloads/amonet]# sudo ./fastboot-step.sh
Your device will be reset to factory defaults...
Press Enter to Continue...

< waiting for any device >

After reboot, nothing happens on a blank screen for over a minute and then the amazon logo appears and goes to recovery mode and does not load the hacked fastboot.

I can manually shoot reboot to bootloader and just get the following, since it is not the hacked bootloader and just the regular one.

Sending 'recovery_x' (13196 KB) OKAY [ 0.479s]
Writing 'recovery_x' FAILED (remote: 'the command you input is restricted on locked hw')
fastboot: error: Command failed

I've tried brick.sh and brick-9820.sh and then bootrom-step, but either way my tablet never boots directly to the hacked fastboot, just boots to recovery, so I am unable to proceed past bootrom-step.