APC Version 0.24.x BIOS Rip

It’s doubtful that this is anything VIA cares that we distribute, but if so – feel free to email us at copyright at openschemes to have it removed.  Please note that the file was inspected and there are no copyright notices within the binary data itself.


One item that seemed immediately interesting was the MX25L4006E serial EEPROM that is located on the lower left region of the board, marked BIOS.  We assume that this is the 2nd level bootloader of the WM8750, read immediately on boot by whatever hard or firm code is stored in the Wm8750 itself.  The job of this 2nd level bl is presumably to begin configuring the hardware ala U-boot, query and initialize the flash memory, and fetchunpack the initrd.gz for whatever operating system the board is going to run.  Dumping the IC’s contents reveals that the binary data is nearly identical to SF_BOOTROM.bin that is freely distributed in the firmware distribution.  HOWEVER, the bootrom that is flashed to our device seems to contain U-boot 0.24.x whereas the distribution contain 0.8.x.

It’s quite likely that the distributed version is simply an improved revision of the boot core and corresponding u-boot, supporting more device types for easier production.  But SOMETIMES, goodies that are available in early versions are reduced or removed as the device matures – such is often the case with serial terminals and other “debug-only” type support.

We will tell you that based on the text strings you can see inside this bootrom, there is an extremely full-featured console just waiting to be explored.  Obtaining serial port connectivity would be quite entertaining.

So for fun and archival value, we present to you the original binary data from the APC BIOS chip, board serial number somewhere between 500 and 1000.


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