Please refer to following links, I hope this will help in understanding of linker generated address and virtual process address space: http://www.linuxjournal.com/article/6463?page=0,0 http://www.tenouk.com/ModuleW.html Regards. Piyush On Fri, Sep 30, 2016 at 10:39 PM, <roman@xxxxxxxxxx> wrote: > Hi, > > I compile main.s and it generates main.o. With objdump I can see: > > 0000000000000000 <_start>: > 0: b8 01 00 00 00 mov $0x1,%eax > 5: bb 00 00 00 00 mov $0x0,%ebx > a: cd 80 int $0x80 > > After link main.o it generates main. With objdump I now can see: > > 0000000000400078 <_start>: > 400078: b8 01 00 00 00 mov $0x1,%eax > 40007d: bb 00 00 00 00 mov $0x0,%ebx > 400082: cd 80 int $0x80 > > So, linker generates virtual address, doesn't it? But why it starts at > 400078 and not in other any location? Is there any logic here? A virtual > address can start at 0? > > Regards. > > El 29.09.2016 09:25, arshad hussain escribió: > > > On 28-Sep-2016, at 10:36 am, Madhu K <madhu.sk89@xxxxxxxxx> wrote: > > Hi All, > > > The support comes right through from the architecture. > > Linear address: Also virtual address. This is Address CPU can address. This > is 0 - 4GB under 32bit architecture. > Physical address: This are actual memory installed in your system. Linear > address have to be converted to > physical address eventually. MMU translate linear address with the help of > paging to physical address. > > > > This is to understand the Virtual address space.Basically who generates the > virtual addresses CPU or GNU compiler? > > > A program image generated by compiler & linker uses Virtual Address . During > execution of the program CPU + MMU > translates or maps each virtual address to physical address. > > Net-net this is architecture dependent and would highly recommend reading > Intel's Architecture Manual for your reference. > > > Thanks > Madhu > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
