Hi all, When I ran full system mode of gem5 with --mem-size=4GB and --disk-image=/dist/m5/system/disks/linux-x86.img, it gave me a warn message that
> warn: Physical memory size specified is 4GB which is greater than 3GB. Twice the number of memory controllers would be created. And the slave terminal said > Memory: 4043292k/5242880k available (3742k kernel code, 150376k reserved, 1874k data, 232k init) It seems gem5 simulated 5GB for me while I requested for 4GB. I searched it and found a [changeset](http://repo.gem5.org/gem5?cmd=changeset;node=fae4550d2103) which said > On the PC platform, the memory region 0xC0000000-0xFFFFFFFF is reserved for various devices. Hence, if the physical memory size is greater than 3GB, we need to split it into two parts. I still have no idea why gem5 do that even I saw the comments aforementioned. I know linux kernel will reserve 0xC0000000-0XFFFFFFFF virtual address for kernel. But I'm not sure if it is related. I conclude my questions again - Why does gem5 create twice the number of memory controllers while physical memory size is greater than 3GB - Why does gem5 simulate 1GB memory more while specified memory size is greater than 3GB --- Sincerely, Sandnon _______________________________________________ gem5-users mailing list [email protected] http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
