What does "SoC bringup" mean?
"SoC bringup" generally refers to the process of porting an operating system to a new embedded system that incorporates an SoC chip. This includes tasks such as:


Assisting with the hardware debug by writing low-level test code to exercise memory and peripheral interfaces.
Making sure that the bootloader can communicate with the specific boot device, and verifying that the entire boot process works correctly. This could also include writing a driver that allows an initial boot image to be written to a blank boot device.
Verifying that OS-level device drivers exist for the specific peripherals being used. This could include writing custom drivers for application-specific hardware.
Making sure that the debugging mechanisms for application-level code are in place and working properly. This could include some combination of JTAG (hardware) based debugging or something like gdb running over a network interface.


Together, these things are sometimes called a "board support package", or BSP.