Hi , Reply Inline . > An empty region of memory is where there exist no > physical ram / io memory. > I can quote a real life example. > I had a pci bridge and some devices on the secondary > side of the bridge. > I configured 1 MB > starting from 0x8000_0000 for the bridge. i.e, any > access to this > address will fetch data from the pci devices > then I do a request_mem_region (0x80000000, > 0x00100000, "pci_non_trans"); Just to clarify 0x8000_0000 or 2GB address is the PHYSICAL address where the PCI bridge exists and reserves 1MB address from here onwards , right ? Is there a way to find the PHYSICAL ADDRESSES of all the devices used in a Computer ? For example, I would like to know what is the PHYSICAL ADDRESS of RAM in my computer or the PHYSICAL ADDRESS of my Hard disk ? Is there any proc entry that can be used to find the PHYSICAL Addresses or any tool to probe this ? Also , does the VM in linux translate the memory address of programs into actual Physical addresses of RAM , or is it that Hardware does the actual translation to Physical addresses ( since the RAM addresses would differ across different Computers depending on the amount of RAM & also the Motherboard design ) . Any additional pointers would be helpful . TIA . Cheers ! > An ioremap () on the returned address will give a > virtual address which > can be used for accessing it. > now assume that the same code is run without the > bridge present, the > above code will succeed, but > the read / write into the memory obtained will not > make any effect. > Because it is empty. No physical > memory corresponds to it. > > HTH. > om. > > -- > Kernelnewbies: Help each other learn about the Linux > kernel. > Archive: > http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > > _______________________________ Do you Yahoo!? Declare Yourself - Register online to vote today! http://vote.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
