On Saturday 25 November 2006 05:08, Hollis Blanchard wrote: > OK, I don't have a problem with this. We should clarify the spec. > It will limit e.g. module sizes and addresses to less than 4GB, but > practically speaking I don't think that is too big a deal.
I agree, although I don't know what will happen in the future. ;) > However, there are 32-bit architectures that support 36-bit addressing > (PowerPC is one of them). In some cases, physical IO is above 4GB, so > some other data structure would be required to identify those devices. > So we must remember that multiboot will not be adequate to describe an > entire system like the Open Firmware device tree does. I am afraid that you misunderstand the meaning of the addressing size in the Multiboot Spec. It only means how a boot loader should inspect memory-related values. For instance, the addresses in a Multiboot header. You can still pass arbitrary size of values in Multiboot information, regardless of 32-bit or 64-bit. > Do we really need x86_64-pc's "bit 17", which specifies that 64-bit > addresses are required? I don't know, for x86_64. The idea is to pass something "natural". My assumption was that, if an image is ELF64, the user wants to use 64-bit pointers, even if real addresses never be over 4GB. Someone who has experience should tell us. Okuji _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
