/* This document is intended to provide the developer with information * how to integrate a new CPU (MACH) into this part of the U-Boot tree */ /** @page dev_arm_mach ARM based CPU (MACH) into the tree FIXME @par What's happens when the reset signal is gone @note Code running immediately after reset runs at an address it is not linked to: "runtime address != link address". You should only use branches and do not refer to fixed data. This implies the use of assembler code only. The ARM CPU starts at lable \ in one of the corresponding start-*.S files. After some basic hardware setup it can call a function \ if not disabled. This call is intended to give all developers a chance to use a standard reset vector file, but also do some special things required only on their specific CPU. After handling some MMU related things \ can be called (if not disabled). This is a board specific function for SDRAM setup for example. As its board specific, your can do whatever you need to bring your board up. When \ returns it will be assumed there is now a working RAM that can be used for all further steps. Next step is relocation of U-Boot itself. It gets copied to RAM and the last assembler instruction is a jump into \. This target address is the first C instruction in U-Boot. At this point of time:\n "runtime address == link address". */