I purchased a couple of these in December 2023 because the price was right and I just needed a device capable of reliably displaying an RTSP stream on a TV.
https://www.aliexpress.us/item/3256805259485409.html
A serial console (115200 8n1) is available on the center two pins of J3, +3.3v on the SQUARE pin, ground is the remaining pin. You do not need to apply voltage, leave the power disconnected and power the board via the 12v plug.
This system uses uBoot and is interruptible (it says "any key" but only ^C seems to work for me).
isvp_a1# printenv
baudrate=115200
bootargs=console=ttyS1,115200n8 asc_sn=0002fb9b85a15300000000000000000000000003ec00000000 flash_type=0 init=/linuxrc rootfstype=squashfs root=/dev/mtdblock3 ro board_type=0x3ec local_av=1 have_face=0 system_mode=0 mtdparts=jz_sfc:192K(uboot),64K(env),1856K(kernel_m2),12288K(rootfs_m3),1920K(config_m4),64K(logo_m5) licence=1.5 libata.force=1.5Gbps mem=190M@0x0 rmem=66M@0xbe00000
bootcmd=sf probe 0x0; sf read 0x80600000 0x40000 0x1d0000;bootm 0x80600000;
bootdelay=1
eth0mii=rmii
eth1addr=00:11:22:56:96:70
eth1mii=rgmii
ethact=mii0
ethaddr=00:53:a1:85:9b:fb
ethprime=mii0
ethrotate=no
gatewayip=193.169.4.1
ipaddr=193.169.4.151
jpeg_addr=0x81000000
jpeg_size=0x10000
loads_echo=1
netmask=255.255.255.0
serverip=193.169.4.2
stderr=serial
stdin=serial
stdout=serial
system_mode=0
vobuf=0x8f600000
bootargs specifies init=/linuxrc, this is standard busybox init.
/linuxrc -> /etc/init.d/rcS -> /etc/init.d/S99ants
This script mounts the various mtd devices, populates /var/ from /etc/soft_link/, then runs /mnt/mtd/app/init_board.sh
init_board.sh performs a lot of housekeeping, and eventually invokes the nvr software, the GUI, an update manager, etc.
root:CYjoTKVIDJ0bg:0:0::/root:/bin/sh
Standard DES crypt, the password is "tianwang". You can login as root on the serial console.
It tries pretty hard to phone home, even before system setup.
Configured/DHCP DNS is ignored, it directly probes various public nameservers (8.8.8.8, 223.5.5.5, 223.6.6.6)
Attempts to connect to an MQTT server (public.iot-as-mqtt.cn-shanghai.aliyuncs.com)
After initial configuration and disabling of P2P (app) and NTP it appears to stop attempting outbound connections.
ants_diagnose liblive.so
ants_gui liblog_manage.so
ants_system libmodel.so
audio libnetwork.so
consoleToTelnet.sh libonvif_mxml.so
ddns libonvif_server.so
default_config libplatform.so
flash_cache.sh libplayback.so
gui_custom_company_config.xml libqrencode.so
host librecfile_rw.so
impdbg librecord.so
init_board.sh libremote_agent.so
insmod_nfs.sh librtmp_proxy.so
ivs_lib librtsp_proxy.so
libaccess_manage.so libsmart.so
libarp_tool.so libsqlite3.so
libatasmart.so libsqlitecpp.so
libbackup.so libss.so.2
libblkid.so.1 libupgrade.so
libcfg_manage.so libuser_manage.so
libcom_err.so.2 libutility_plat.so
libdiscovery.so libuuid.so.1
libdisk_manage.so libws_proxy.so
libe2p.so.2 logcat
libext2fs.so.2 mpp
libfdisk.so.1 noauthority.nvr
libgb28181.so protocal_lib
libhandle.so.1 serial
libhot_spare.so soft_version.xml
libhttp_proxy.so telnetToConsole.sh
libhttp_server.so tool
aliIoT4nvr ants_object_config.xml
ants_absent_config.xml ants_od_config.xml
ants_ai_config.xml ants_parking_config.xml
ants_ao_config.xml ants_ptz_soft_ctrl_cfg.xml
ants_channel_device_config.xml ants_record_config.xml
ants_counter_config.xml ants_region_config.xml
ants_electric_config.xml ants_retrograde_config.xml
ants_exp_config.xml ants_staying_config.xml
ants_gui_config.xml ants_system_config.xml
ants_gui_priview_config.xml ants_usr_config.xml
ants_hd_config.xml ants_vlost_config.xml
ants_humanoid_config.xml ants_wire_config.xml
ants_invasion_config.xml custom
ants_iptables_rule_cfg.xml hostmgr_autoupgrade
ants_md_config.xml reserve
ants_network_config.xml upgrade_restore_factory