Some SoC have bootstrap options. As far as I understand it controls how a device( using that SoC) starts.
E.g. SoC BCM7440 ,made by Broadcom and that is used in a blue ray devices , has several bootstrap options and one is
strap_test_debug_en_ , which probably enables debugging. But what kind of debugging? JTAG, UART or different? Can anyone explains? Thank you