* William Case <billlinux [ at ] rogers [ dot ] com> [071003 11:55]: > > http://www.osdata.com/system/physical/memmap.htm > > Thanks. Shows layouts for DOS and MAC. I assume that re: Bios Linux OS > would be the same as DOS, because the code is stored before any OS > begins ?? Linux only calls 3 BIOS services (if you don't use APM) and then forgets BIOS ever existed. > > ... but since the early nighties (when the above was everything you > > needed to know) it's gotten worse. Now USB, ACPI, ATA, VIDEO, and other > > parts of the BIOS reserve various regions. > > > > INT 0x15, service 0xE820, was added for OS software to get the layout of > > usable memory on the system. This will list about 5 regions reserved to > > different parts of the BIOS. It also lists the physical memory regions > > that the OS can use for whatever it wants. > > > > Write a small C program to get access to this table/layout -- I > assume ?? You cannot access it once Linux is running. But you could write a small program under DOS to access it. You could even run this DOS in emulation (qemu, bochs, dosemu, etc) under Linux. > > > first and last address of my memory, > > > BIOS that has been written to memory, > > > Kernel space, > > > User space, > > > shell, > > > processes (running and sleeping), > > > > The above is not how you want to look at things. User space runs in > > virtual memory, which is seldom contiguous in physical memory. > > Understood. But nonetheless I had hoped there was some organized > fashion by which it could be invisioned. Pages used by the application are scattered throughout physical memory. The only thing I have seen that comes close to visualizing application memory usage is Matt Mackall's Pagemap tool. http://selenic.com/Screenshot-pagemap.png I don't know how polished any of those tools are. -Bart -- WebSig: http://www.jukie.net/~bart/sig/
