The BIOSLoader is designed to support an x86 processor-based device and is dependent on the BIOS firmware that all x86 processor-based devices are built with. The BIOSLoader does not contain the code to initialize system hardware for the target device. It’s dependent on the x86 BIOS to initialize system hardware.
You can configure the BIOSLoader to launch a Compact 7 OS run-time image from the local storage. You can also configure it to launch the Eboot bootloader to establish connectivity with the development station to download an OS run-time image.
Following are the startup sequences for a typical x86 processor-based device:
1. After power is applied to the device, the x86 processor jumps to the reset vector address and executes the BIOS code.
2. The BIOS code initializes the hardware and searches for a bootable storage device.
3. After detecting a bootable storage device, the BIOS locates and loads the master boot sector (MBR) to the system memory.
4. As the MBR code runs, it searches for the boot sector image on a valid partition, loads the boot sector image into the system memory, and kick starts the boot sector code.
5. As the boot sector code runs, it finds and loads the BIOSLoader.
6. As the BIOSLoader runs, it finds and loads the OS run-time image into system memory and jumps to the starting address to launch the image.
The BIOSLoader is provided as part of the CEPC BSP for Compact 7, in the following directory: