Ankit Jain wrote:
thanks a lot for helping all the way
see inline
--- Jim Nelson <[EMAIL PROTECTED]> wrote:
Ankit Jain wrote:
LThi
http://www.xml.com/ldd/chapter/book/ch02.html
00000000-0009fbff : System RAM
0009fc00-0009ffff : reserved
000a0000-000bffff : Video RAM area
000c0000-000c7fff : Video ROM
000f0000-000fffff : System ROM
00100000-03feffff : System RAM
00100000-0022c557 : Kernel code
0022c558-0024455f : Kernel data
20000000-2fffffff : Intel Corporation 440BX/ZX -
82443BX/ZX Host bridge
68000000-68000fff : Texas Instruments PCI1225
68001000-68001fff : Texas Instruments PCI1225 (#2)
e0000000-e3ffffff : PCI Bus #01
e4000000-e7ffffff : PCI Bus #01
e4000000-e4ffffff : ATI Technologies Inc 3D Rage
Pro AGP-133
e6000000-e6000fff : ATI Technologies Inc 3D Rage
LT
<>Pro AGP-133 fffc0000-ffffffff : reserved what is it reserved for?
if somebody can explin me this:
"Once again, the values shown are hexadecimal ranges, and the string after the colon is the name of the "owner" of the I/O region."
What you are seeing is the remapped I/O space for
various components in your computer. During bootup, the kernel scans the
various buses and identifies various devices. Each driver remaps the
I/O space for PCI devices - "they are physical addresses in that those
memory addresses do map to real devices, but they are not real memory
addresses."
what do u mean by this? they are physical address but not the real memory address? what do u mean by physical address then?
Most modern computer components have an I/O range built in - like a graphics card, for example, will have the pixel maps, etc. for the display, an IDE controller will have a configuration area, status information, etc. Using PCI for an example, each adapter card has a certain amount of memory and register space. The virtual addresses allow you to use standard memory-oriented commands to access the devices. The x86 system has a different set of machine instruations for I/O (at least for the legacy components - serial & parallel ports, keyboard, mouse, system speaker, etc.) but most other architectures don't have that same kind of split - you just segment off an area of the address space and call it an adapter. It's not the easiest thing in the world to grok - I just barely understand it myself.
IIRC, the "reserved" area is the remapped kernel
address space - they set it up to remap to the top of the 32-bit memory
address range in order to allow hard-coded function calls - it is
faster to hard-code the function calls than to maintain symbol tables.
what is hard coded funtion calls? is it something like stting the pointer to starting location?
More like not having to go to a call table or calculate relative offsets. It saves time, to keep addresses of various parts of the kernel in predictable places. Any large program (Windows programs come to mind) will load various parts of itself at different times. Keeping track of where in memory all those functions are located takes processor time - for each subroutine called.
If you don't allow things to move around in memory, you can just jump to the address of the target subroutine. No fuss, no bother. That's how DOS interrupts were handled, by the way - you had to load your interrupt handler at a specific location in memory. It makes for a smaller, faster executable at the cost of some fragility when you try and muck with it.
Sorry if that's a little confused, but I'm just starting to get my chops on w/ programming anything beyond silly toys.
I see this computer is a laptop - now I understand
why you are reluctant to upgrade the RAM.
what tells that this is a laptop?
68000000-68000fff : Texas Instruments PCI1225 68001000-68001fff : Texas Instruments PCI1225 (#2)
Texas Instruments CardBus slots. Educated guess - there are CardBus-to-PCI adapters available, but are pretty rare - not the kind of things that you'd see in a novice's computer. I'm looking at getting one myself, but that's because I have a project for my day job that involves some PCMCIA hacking, and my old laptop isn't feeling up to the job, I think.
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