The hardware is the same as the S7 (same FCC ID), which has been dismissed years ago for not having enough RAM and a not supported SoC.
What makes it ( TP1900BN / MT7626 ) really unsupported? (aside from the 32MB RAM requirement) I haven't tried flashing anything on it yet as I couldn't find any DTS files for MT7626.
This device is clearly running OpenWrt as it can be seen from the serial console but sources are nowhere to be found on TP-Link GPL site.
F0: 102B 0000
F1: 0000 0000
V0: 0000 0000 [0001]
00: 0000 0000
BP: 0000 0041 [0000]
G0: 0190 0000
T0: 0000 0202 [000F]
Jump to BL
U-Boot SPL 2014.04-rc1-g292d386 (Oct 14 2022 - 17:48:21)
Hello, MT7626 E2
RGU MODE: 4d
RGU LENGTH: ffe0
RGU STA: 0
RGU: g_rgu_satus:0
PL P ON
WDT does not trigger reboot
RGU mtk_wdt_init:MTK_WDT_DEBUG_CTL(590200f3)
PCDDR2 type with 1066MHz.
[MEM_TEST] OK.
SPL: Decompressing U-Boot image!
Actual U-Boot image size: 0x3d354
image entry point: 0x41E00000
U-Boot 2014.04-rc1-g292d386 (Oct 14 2022 - 17:48:21)
static declaration g_total_rank_size = 0x 2000000
DRAM: 32 MiB
board_gpio_init mac0 0x5450206f
board_gpio_init mac1 0x62657920
board_gpio_init mac2 0x74686520
board_gpio_init mac3 0x47504c0a
NOR: *** Warning - bad CRC, using default environment
In: serial
Out: serial
Err: serial
*** Warning - bad CRC, using default environment
Net: mtk_eth
Uip activated
Autobooting in 1 seconds
MT7626> help
? - alias for 'help'
bootm - boot application image from memory
cp - memory copy
env - environment handling commands
erase - erase FLASH memory
go - start application at address 'addr'
help - print command description/usage
httpd - httpd - start www server for firmware recovery
jmpaddr - Jump to Normal Uboot
md - memory display
printenv- print environment variables
reset - Perform RESET of the CPU
setenv - set environment variables
snor - snor - spi-nor flash command
tftpboot- boot image via network using TFTP protocol
MT7626> printenv
arch=arm
baudrate=115200
board=leopard_evb
board_name=leopard_evb
bootcmd=jmpaddr 0x30025080
bootdelay=1
bootfile=lede_uImage
cpu=armv7
ethact=mtk_eth
ethaddr=47:4E:55:47:50:4C
ipaddr=192.168.0.1
loadaddr=0x40200000
serverip=192.168.0.3
soc=leopard
vendor=mediatek
Environment size: 296/4092 bytes