bricked my ar750 by manipulating uboot, got this in serial:
U-Boot 1.1.4-gbeb0f336 (Oct 25 2017 - 14:12:34)
DRAM: 128 MB
Nor Flash: 16 MB, sector count = 256
ath_spi_nand_ecc: Couldn’t enable internal ECC
Protect off 9F040000 … 9F04FFFF
Un-Protecting sectors 4…4 in bank 1
Un-Protected 1 sectors
Erasing Flash…Erasing flash…
First 0x4 last 0x4 sector size 0x10000 4
Erased 1 sectors
Writing to Flash… write addr: 9f040000
Protecting sectors 4…4 in bank 1
Protected 1 sectors
Warning: Bootlimit (3) exceeded. Using altbootcmd.
Un-Protect Flash Bank # 1
Hit any key to stop autoboot: -99
Cannot find art, please flash the default art first.
i dont have original art partition backup, who can share one?