On Mon, 2008-08-18 at 13:35 +0200, Sébastien Chrétien wrote: > Can somebody explain me the aim of the function "setup_arch" in the > machine_call structure ?
This is where most of your arch code gets a chance to initialize before most of the core is. The generic core linux code calls the architecture setup_arch() very early during boot, before most other initializations. The powerpc architecture code performs various early initialisations there, on 32-bit that includes unflattening the device-tree, looking for legacy serial ports, etc... and initializing bootmem. It then calls ppc_md.setup_arch to give the platform a chance to perform other platform specific early initializations before the rest of the kernel starts initializing. This is very early, ie, for memory allocation you can only use bootmem for example. Interrupts haven't been initialized or switched on yet, etc... This is typically the place where your arch code will setup it's SMP ops if any, will discover the fixed PCI host bridges, and initialize low level HW components that need early initialization. Ben. > 2008/8/18, Sébastien Chrétien <[EMAIL PROTECTED]>: > Ok I am going to copy some examples. > > 2008/8/18, Benjamin Herrenschmidt <[EMAIL PROTECTED]>: > On Mon, 2008-08-18 at 10:45 +0200, Sébastien Chrétien > wrote: > > Hello, > > > > I am developping a Linux for my PPC Board. I must > write a > > define_machine structure (marchdep_calls). Where can > I find some > > Information about functions of this structure ? > > > It isn't well documented unfortunately. Best is to > look at what others > do... and then find your way through. > > I agree somebody should write dome doco one day ... in > the meantime, > feel free to ask questions here. > > Cheers, > Ben. > > > > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
