AHB780XTB Digital Video Recorder

AHB78XTB-3520D is a digital video recorder mainboard based on the HiSilicon Hi3520D SoC, and used in DVRs of multiple brands, such as Conceptronic.

Multiple board revisions exist. My board is marked as V1.01.

Notable components

• Hi3520DRQCV100 SoC
• SAMSUNG RAM, 2Gb (256 MiB)
• MX25L64 flash (8 MiB)
• nextchip NVP1918C analog video capture chip

UART access

CN11 is an unpopulated 3-pin header, which appears to be a debug serial port.

pin	description
1	UART0 RX
2	UART0 TX
3	GND

The TX pin doesn't appear to have a pullup, so you may need an external pullup.

The kernel/userspace doesn't print anything on the serial port, but U-Boot prints some information and pressing Ctrl-C during boot opens a U-Boot shell.

U-Boot 2010.06-svn194 (Oct 17 2014 - 12:05:59)

Check spi flash controller v350... Found
Spi(cs1) ID: 0xC2 0x20 0x17 0xC2 0x20 0x17
Spi(cs1): Block:64KB Chip:8MB Name:"MX25L6406E"
envcrc 0x1d247f25
ENV_SIZE = 0xfffc
In:    serial
Out:   serial
Err:   serial
USB:   scanning bus for devices... 1 USB Device(s) found
0 Storage Device(s) found
Press CTRL-C to abort autoboot in 0 seconds8192 KiB hi_sfc at 0:0 is now current device

CFG_BOOT_ADDR:0x0
0ff:0x84000000
### /UbootLogo UbootLogoload complete: 28285 bytes loaded to 0x8e800000
jpeg decoding ...
<<addr=0x8e800000, size=0xb85f9, vobuf=0x8e800000>>
<<imgwidth=800, imgheight=600, linebytes=1600>>
decode success!!!!
decode jpeg success.
decode jpeg!

srcAddr 0x82000000, dstAddr 0x82000000
find_squashfs_file: name bin, start_block 0, offset 1284, type 1
find_squashfs_file: name boot, start_block 0, offset 1376, type 1
read inode: name boot, sb 0, of 1376, type 1
find_squashfs_file: name zImage.img, start_block 0, offset 1316, type 2
read inode: name zImage.img, sb 0, of 1316, type 2
### FS load complete: 1613452 bytes loaded to 0x82000000
## Booting kernel from Legacy Image at 82000000 ...
   Image Name:   linux
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    1613388 Bytes = 1.5 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Loading Kernel Image ... OK
OK

Starting kernel ...

Uncompressing Linux... done, booting the kernel.