[Haku]

I really need some help on this. I damaged my preloader on a BLU Vivo XL4 by running:

fastboot flash preloader preloader_k62v1_64_bsp.bin

Now all i get in SP Flash Tools is STATUS_EXT_RAM_EXCEPTION

[X3non]

I really need some help on this. I damaged my preloader on a BLU Vivo XL4 by running:

fastboot flash preloader preloader_k62v1_64_bsp.bin

Now all i get in SP Flash Tools is STATUS_EXT_RAM_EXCEPTION

disconnect / reconnect the battery of the device then retry flashing preloader using sp flash tool
ensure to use the DA for model when flashing, you can download @ https://forum.hovatek.com/thread-26122.html

[Haku]

Thanks for the response. The battery is non-removable. I tried those DA files for my device already but I'm getting the same error. Before I bricked it, I managed to unlock the bootloader by running:

fastboot oem unlock

Also when I run the exploit at https://github.com/MTK-bypass/bypass_utility, it gives me following output (so I don't even think I need DA files):

[2021-02-06 12:15:03.622167] Waiting for bootrom
[2021-02-06 12:15:38.508022] Found port = COM7
[2021-02-06 12:15:38.531108] Device hw code: 0x766
[2021-02-06 12:15:38.531608] Device hw sub code: 0x8a00
[2021-02-06 12:15:38.531608] Device hw version: 0xca00
[2021-02-06 12:15:38.531608] Device sw version: 0x0
[2021-02-06 12:15:38.532111] Device secure boot: False
[2021-02-06 12:15:38.532111] Device serial link authorization: False
[2021-02-06 12:15:38.532611] Device download agent authorization: False
[2021-02-06 12:15:38.532611] Disabling watchdog timer
[2021-02-06 12:15:38.533613] Insecure device, sending payload using send_da
[2021-02-06 12:15:38.572376] Found send_dword, dumping bootrom to bootrom_766.bin

My other question is: Can that exploit (bypass_utility) be modified in such a way that it can write back the correct preloader to the device? As it seems to be the only tool that works with it ATM.

[X3non]

Thanks for the response. The battery is non-removable. I tried those DA files for my device already but I'm getting the same error. Before I bricked it, I managed to unlock the bootloader by running:

fastboot oem unlock

Also when I run the exploit at https://github.com/MTK-bypass/bypass_utility, it gives me following output (so I don't even think I need DA files):

[2021-02-06 12:15:03.622167] Waiting for bootrom
[2021-02-06 12:15:38.508022] Found port = COM7
[2021-02-06 12:15:38.531108] Device hw code: 0x766
[2021-02-06 12:15:38.531608] Device hw sub code: 0x8a00
[2021-02-06 12:15:38.531608] Device hw version: 0xca00
[2021-02-06 12:15:38.531608] Device sw version: 0x0
[2021-02-06 12:15:38.532111] Device secure boot: False
[2021-02-06 12:15:38.532111] Device serial link authorization: False
[2021-02-06 12:15:38.532611] Device download agent authorization: False
[2021-02-06 12:15:38.532611] Disabling watchdog timer
[2021-02-06 12:15:38.533613] Insecure device, sending payload using send_da
[2021-02-06 12:15:38.572376] Found send_dword, dumping bootrom to bootrom_766.bin

My other question is: Can that exploit (bypass_utility) be modified in such a way that it can write back the correct preloader to the device? As it seems to be the only tool that works with it ATM.

you'd need to disassemble the back to get to the battery clip, after disconnecting / reconnecting the battery then retry both methods
btw it's already known that xl4 has secure boot unless yours is a clone? try the battery disconnection and ensure you are using stock firmware for the xl4 model

the bypass_ultility is only meant to remove protection not to flash the device, to flash you need spft with connection settings set to use UART with highest baudrate speed

[Haku]

Well it's been a while but it turns out I was using the wrong preloader. It seems not all XL4s use the same preloader? Because the common one found with the ROMs does not work with my device.

[kelvinchinedu]

Try dismantling the battery,and reflash only preloader first

[Haku]

Try dismantling the battery,and reflash only preloader first

Sorry if I was not clear enough. The device is fixed (mostly) and booting now. All that was needed was to flash the correct preloader. This thread can be closed / ignored now.