Bricked SoC ? Stuck in MaskROM mode, unable to update firmware

I hope my mistake can be repaired. Some weeks ago I seemingly bricked my RK3399 SoC, because I followed an advice from some internet tutorial advising to erase some blocks using an upgrade_tool ws 0xsome_address /dev/null or something like that. It was a rather small address.

Since then I can only boot in MaskROM mode, but what worries me the most is that the size of the flash memory is displayed to be zero :

sudo ./upgrade_tool rfi

Flash Info:

        Manufacturer: SAMSUNG,value=00
        Flash Size: 0MB
        Block Size: 512KB
        Page Size: 2KB
        ECC Bits: 0
        Access Time: 40
        Flash CS:

Also I cannot simply wipe out / upgrade the emmc firmware like I used to do :

sudo ./upgrade_tool uf ffly/stock/FIREFLY-RK3399_Ubuntu20.04-r240_v2.5.1d_230330.img
Program Log will save in the /root/upgrade_tool/log/
Loading firmware...
Support Type:RK330C     FW Ver:8.1.00   FW Time:2023-03-30 16:11:48
Loader ver:1.1a Loader Time:2023-03-30 16:11:20
Download Boot Fail

Is there a way to solve this and hard reset the SPI/emmc ? Probably using the electric pins ? Thank you.

PS I don’t mind which platform to use, this is posted from Linux using manjaro live usb but I have a spare Windows computer among others.

Hello ? Can anyone tell me whether I can fix my own card, or else if I need to return it to the staff for repairing ?

I opened a thread on r/SBCs.

rkflashtool on MacOS gives the most information: this is what I get after having booted the card in Maskrom mode and attempted to write/update the emmc:

sylvansab@mac ~ % cd hack/ffly/ubuntu-image
sylvansab@mac ubuntu-image % l
CLIoutImageMiniLoaderAll.binpackage-fileparameter.txt
sylvansab@mac ubuntu-image % rkflashtool w miniloader <MiniLoaderAll.bin
rkflashtool: info: rkflashtool v6.1
rkflashtool: info: Detected RK3399...
rkflashtool: info: interface claimed
rkflashtool: info: MASK ROM MODE
libusb: warning [darwin_transfer_status] transfer error: device not responding (value = 0xe00002ed)
libusb: warning [darwin_transfer_status] transfer error: device not responding (value = 0xe00002ed)
rkflashtool: info: working with partition: miniloader
libusb: error [submit_bulk_transfer] bulk transfer failed (dir = Out): pipe is stalled (code = 0xe000404f)
libusb: error [submit_bulk_transfer] bulk transfer failed (dir = In): pipe is stalled (code = 0xe000404f)
libusb: error [submit_bulk_transfer] bulk transfer failed (dir = In): pipe is stalled (code = 0xe000404f)
rkflashtool: fatal: invalid size of parameter block
sylvansab@mac ubuntu-image % rkflashtool w 0x40 MiniLoaderAll.bin
rkflashtool: info: rkflashtool v6.1
rkflashtool: info: Detected RK3399...
rkflashtool: info: interface claimed
rkflashtool: info: MASK ROM MODE
libusb: warning [darwin_transfer_status] transfer error: device not responding (value = 0xe00002ed)
libusb: warning [darwin_transfer_status] transfer error: device not responding (value = 0xe00002ed)
... Done!
sylvansab@mac ubuntu-image % rkflashtool w 0x4000 Image/boot.img
rkflashtool: info: rkflashtool v6.1
rkflashtool: info: Detected RK3399...
rkflashtool: info: interface claimed
rkflashtool: info: MASK ROM MODE
libusb: warning [darwin_transfer_status] transfer error: device not responding (value = 0xe00002ed)
libusb: warning [darwin_transfer_status] transfer error: device not responding (value = 0xe00002ed)
... Done!