>> > 2) The Memory Map information under GRUB2 seems to be "zeroed" which >> > leads me to believe that there must be something different in the way >> > Legacy GRUB and GRUB2 handle Data and BSS segments (ie: initializing >> > data by zeroing out). >> The most common reason is the OS zeroing it out. Legacy put the memory >> map in lowmem. GRUB2 puts it just after the kernel image. Some kernels >> may overwrite it during an initialisation phase. > > That will explain it. If GRUB2 puts the memory map just after the > kernel image then it means that the OS cannot assume that the memory > range immediately after the kernel image is free. In fact, the > multiboot OS "must" use the provided memory map to decide what ranges of > memory are available for "dynamic memory" and which of it is free. I > mistakenly thought that the memory map will always be in low memory and > only assume that the first 1 MB of physical memory should be left alone > at boot time to preserve the information. > > BTW, why the difference? Was putting multiboot information (eg: memory > map) in low memory clobbering BIOS information or the VGA/EGA/CGA memory > mapped areas? Just curious. Multiboot specification never promised anything about where mbi is stored. Read it here: http://www.gnu.org/software/grub/manual/multiboot/. Don't assume anythin not explicitly stated in this document > > Thanks for clearing that up! > > Peace, > Frank > >> > >> > I am using GRUB2 version 1.96 from the Fedora RPM repository; hence, I >> > wanted to know if a later SVN version has a fix or is there a change in >> > the specifications. >> Specifications are the same but we fixed a lot of bugs. >> > >> > Peace, >> > Frank > > > > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > http://lists.gnu.org/mailman/listinfo/grub-devel >
-- Regards Vladimir 'phcoder' Serbinenko Personal git repository: http://repo.or.cz/w/grub2/phcoder.git _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
