Rom dumping for the 8BitKing Game stick

Dumping the rom

1. Put the Resource dir onto the SD card.
2. Put the SD card back into the 8BitKing stick and boot it
3. Wait until a blue screen appears with the message: Grap the dump.bin

Linux:

4. $ tail -c +131201 dump.bin | unlzma > maincode to extract and uncompress the raw dump of the rom.

Windows:

4. You could use Git Bash for tail -c +131201 dump.bin > temp.bin and 7zip for the uncompression: 7z e temp.bin -omaincode. Or you could use wsl but you have to install xz-utils for the uncompression: sudo apt install xz-utils. Then you can follow step 1-4 for linux.

Note: An error that the output file maincode is corrupted is to be expected because maincode is a bisrv.asd (bios) but w/o 512 bytes LCFG header. It's loaded to address 0x80000200 and executed from this address (_start is actually lower so it follows a string of nops)

How to compile src

There's a link to the toolchain in the Makefile. Just unpacked it to /opt on your linux system then just run make whithin the src directory, it creates Resources/Foldername.ini with the exploit and all the code.

The toolchain has been reported to work in WSL2, too, so you don't really have to go fully Linux.

Files

Everything for the dumpers code is in main.c, it's quite simple really. Other source files are supplementary.

The RTOS on this device does not support apps or libraries in any way and was designed as one huge statically linked image.

So Foldername.ini is quite the same, just relocated out of reach.

New Foldername.ini is, obviously, the executable body. It's relocated to the top of the memory in relocate function in main.c then main_task is run.

The 8BitKing game stick

8BitKing is powered by HiChip Semi (HCSEMI) A210C https://en.hichiptech.com/product_1/19.html (Datasheet)

Feature	Details
CPU	800MHz
DRAM	ext. max. 256MB @800Mbps
Flash	SPI Flash
Video Decoder	Multi-format @FHD 60FPS
Display	HDMI_TX+VGA/CVBS
Video Input	DVP/CCIR601/656
Audio	Mono ADAC+I2S in+out/SPDIF out
USB	USB2.0x2
SDIO	SDIO2.0
I2C/UART	3xPWM, 3xI2C+2xUart, 1xSARADC, IRRX
Wi-Fi	A210 Support
SW System	RTOS
Package	eLQFP128
Typical Products	Mobile screen sharing device, Same-screen mods, Game

The main CPU is MIPS32-compatible (Release 1 only) running at 810 MHz, but it's bottlenecked heavily by the DDR2 due to lack of sensible caching (16K for instructions and 16K data, no L2 at all). This CPU lacks an MMU, and is also bug-ridden, freezing on invalid memory accesses.

Famicom only Derivat (Y2S HD(1661 Games)) (D600)

There is a similar stick which has no specific name. It only has a famicom/nes emulator and the main menu has menu points for different categories: e.g. adventure, puzzle, etc.

For this you can use the resource folder inside the FCOnlyStick directory.

The 8BitKing and this Y2S Stick have the same PCB and CPU chip.