009 Embedded Linux-ARM. StorageQueries and discussion related to usage of Linux on ARM based devices. Linux has been ported to a variety of CPUs which are not only primarily used as the processor of a desktop or server computer, but also ARM, AVR32, ETRAX CRIS, FR-V, H8300, IP7000, m68k, MIPS, mn10300, SuperH, and Xtensa processors, It is also used as an alternative to using a proprietary operating system and toolchain. » 009.01.Linux Boot Process
When we push the power on button , raw power comes to POST(Power on Self Test Module). POST helps in stablizing the raw power and convert raw power to Power Good signal having min and max voltage ratings, defined frequency etc. Then Power signal goes to Processor Chip having internal power supply module. It turns on list of the components present in Processor chip , initialize the registers etc.
Execution starts from the predefined address stored in one of the register and that address points to ROM BIOS/UEFI which is present in Processor chip itself and it is readable only, written once only by chip manufacturer.
In ROM UEFI/BIOS, one other address is present which points to external UEFI/BIOS chip and this chip is the part of motherboard outside the processor chip.