This is intended to be a repository for info on the MStar/SigmaStar SoCs. The name is a parody of linux-sunxi for Allwinner SoCs. MStar in Chinese is chenxing and the newer SigmaStar name is xingchen.

This will probably never get as big as linux-sunxi so github pages should be more than enough.

Before MStar was bought out by MediaTek the company offered a wide range of SoCs focused at STB and camera applications. Since the company was bought by MediaTek the camera SoC part of the company has been spun out into the fully owned subsidiary called Sigmastar. The camera SoCs that are now marketed by Sigmastar will be the main focus here.

It’s worth noting that the MStar/Sigmastar camera SoCs seem to be derived from the SoCs made by Alpha Imaging Technology which was merged into MStar at some point.

Porting Progress Matrix


  load u-boot SPL from vendor IPL load u-boot from SPI NOR
infinity yes yes
infinity2m wip wip
infinity3 yes yes
infinity6 wip wip
mercury5 yes yes


  boots to shell from initramfs boots to shell from local storage full system from local storage with network etc
infinity yes yes yes
infinity3 yes yes yes
infinity6 wip wip wip
mercury5 yes wip wip

Reverse Engineering Progress

family part date codes sample device acquired boot rom dumped firmware dumped SDK acquired product brief acquired datasheet acquired
  mst786             yes
infinity1           yes[0]    
  msc313 1647B yes yes        
  msc313d 1638B            
  ssr621d 1945S yes yes yes      
infinity3           yes[0]    
  msc313e 1744B yes yes yes   yes  
  msc316dc 1929S yes same as msc313e yes   yes  
  msc316q           yes  
  msc318           yes  
  ssc323 1928S            
  ssc325 1937S yes yes yes      
mercury2     yes          
  msc8328 1744     yes      
  ssc8336 1915S yes   yes      
  ssc8336n 1918S yes yes yes      
  ssc8339d           yes  


MIPS based

MStar used to make a lot of MIPS based SoCs for STBs. These aren’t that interesting in themselves but the IP blocks used in the MIPS SoCs were carried forward to the later ARM chips so any datasheets that can be found for the MIPS SoCs might help with reverse engineering the current ARM based ones.


ARM based

Cedric Family

Infinity IP camera family

Infinity 1

Infinity 2

Infinity 3

Infinity 5

Infinity 6

Mercury family

Mercury 2

Mercury 5


IP blocks

See IP.

ISP/Debug Tool

See ISP.

Injoinic PMICs

Injoinic seem to be the recommended PMIC vendor for these chips. Maybe like the Allwinner/Xpowers relationship?

Blobs, headers, layouts

Vendor uboot, kernels..

Vendor SDKs

Sources of firmwares for reverse engineering

To get the device tree out of the kernel you can use binwalk + extract-dtb and dtc.

binwalk -e <firmware.bin> <extracted firmware dir><uncompressed kernel blob>
dtc -I dtb -O dts -o out.dts <extracted dtb that looks right>