On Tue, Feb 24, 2015 at 11:53 AM, Vishwas Srivastava <vishu.kernel@xxxxxxxxx> wrote: > > Hi Sannu, > 1G/3G address split is for virtual address. I am not talking about physical address translation stuff here. > When a kernel code is compiled for a 32 bit architecture, my assumption is, compiler will generate the code for the full 4G address range. So there must be somebody who is relocating/translating the kernel code address between 0-4G to 3G--4G address space. > Who is that guy? and is my understanding correct?? > > > On Tue, Feb 24, 2015 at 10:54 PM, Sannu K <sannumail4foss@xxxxxxxxx> wrote: >> >> Address generated by the linker is virtual address, it is not same as physical address. Kernel / MMU will do the virtual to physical address mapping. >> >> Hope this helps, >> PrasannaKumar > > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > I believe it is done as part of kernel image linker script, please have a look at linux/arch/x86/kernel/vmlinux.lds.S. The very first logical address inside script is derived from LOAD_OFFSET (for x86_32) or __PAGE_OFFSET which is 3G mark. Hope I am pointing you in right way. -Rajat _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
