RE: RAM or "empty"?

well it is really unique. actually i could not
understand in this what is this reseved address space.


rest reply inline


--- Learner wrote:
> Hi ,
>
> Reply Inline .
>
> --- "Thekkedath, Gopakumar"
> wrote:
>
> >
> >
> >
> >
> > >Is there a way to find the PHYSICAL ADDRESSES of
> > all
> > >the devices used in a Computer ?
> >
> > does cat /proc/iomem serves the purpose ?
> >
>
> Well , if /proc/iomem gives the PHYSICAL address
> range of devices , then why is the System RAM
> split into 3 different address ranges as seen below
> (marked by arrows ) ? Is it bcoz the Motherboard is
> designed in this manner ?
>
> ~> cat /proc/iomem
> 00000000-0009fbff : System RAM <--- 1

basically this hex range represents 2^32

how much memory area can be accessed by this and what
about rest. 1 mopre ques. suppose i have 1Mb of RAM
for that how many address lines i need

> 0009fc00-0009ffff : reserved

whats this reserve says and why and for what it is
reserved?

> 000a0000-000bffff : Video RAM area
> 000c0000-000c7fff : Video ROM

why do we need to seprate all these areas?

> 000e0000-000effff : Extension ROM
> 000f0000-000fffff : System ROM
> 00100000-1fecffff : System RAM <---- 2
> 00100000-0028dadf : Kernel code
> 0028dae0-00324f63 : Kernel data
> 1fed0000-1feeffff : ACPI Non-volatile Storage
> 1fef0000-1fefffff : System RAM <---- 3
> 40000000-40000fff : Intel Corp. 82801BA/BAM/CA/CAM
> Ethernet Controller
> 40000000-40000fff : eepro100
> 40300000-4037ffff : Intel Corp. 82815 CGC [Chipset
> Graphics Controller]
> 44000000-47ffffff : Intel Corp. 82815 CGC [Chipset
> Graphics Controller]
> feea0000-ffffffff : reserved
>
> Are these memory address ranges dynamically
> determined ? Which kernel code file does this ?
>
> Also , does /proc/ioports represent IO-mapped
> PHYSICAL memory addresses ,
> similar to the the Memory-mapped PHYSICAL memory
> addresses in /proc/iomem ?
>
> ~> cat /proc/ioports
> 0000-001f : dma1
> 0020-003f : pic1
> 0040-005f : timer
> 0060-006f : keyboard
> 0070-007f : rtc
> 0080-008f : dma page reg
> 00a0-00bf : pic2
> 00c0-00df : dma2
> 00f0-00ff : fpu
> 0170-0177 : ide1
> 01f0-01f7 : ide0
> 02f8-02ff : serial(auto)
> 0376-0376 : ide1
> 03c0-03df : vga+
> 03f6-03f6 : ide0
> 03f8-03ff : serial(auto)
> 0cf8-0cff : PCI conf1
> 1000-103f : Intel Corp. 82801BA/BAM/CA/CAM Ethernet
> Controller
> 1000-103f : eepro100
> 2000-20ff : Intel Corp. 82801BA/BAM AC'97 Audio
> 2000-20ff : Intel 82801BA-ICH2 - AC'97
> 2400-243f : Intel Corp. 82801BA/BAM AC'97 Audio
> 2400-243f : Intel 82801BA-ICH2 - Controller
> 2440-245f : Intel Corp. 82801BA/BAM USB (Hub #2)
> 2440-245f : usb-uhci
> 2460-246f : Intel Corp. 82801BA IDE U100
> 2460-2467 : ide0
> 2468-246f : ide1
>
> > >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 ) .

does it really depend on motherboard? or does it
depend on the hardwares stuffs we have on system?

thanks

ankit

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RE: RAM or "empty"?

Hi,

Reply Inline

--- Ankit Jain wrote:

> well it is really unique. actually i could not
> understand in this what is this reseved address
> space.
>
>
> rest reply inline
>
>
> --- Learner wrote:
> > Hi ,
> >
> > Reply Inline .
> >
> > --- "Thekkedath, Gopakumar"
> > wrote:
> >
> > >
> > >
> > >
> > >
> > > >Is there a way to find the PHYSICAL ADDRESSES
> of
> > > all
> > > >the devices used in a Computer ?
> > >
> > > does cat /proc/iomem serves the purpose ?
> > >
> >
> > Well , if /proc/iomem gives the PHYSICAL address
> > range of devices , then why is the System RAM
> > split into 3 different address ranges as seen
> below
> > (marked by arrows ) ? Is it bcoz the Motherboard
> is
> > designed in this manner ?
> >
> > ~> cat /proc/iomem
> > 00000000-0009fbff : System RAM <--- 1
>
> basically this hex range represents 2^32
>
> how much memory area can be accessed by this and
> what
> about rest. 1 mopre ques. suppose i have 1Mb of RAM
> for that how many address lines i need

The Hex range is 2^32 since the output is taken
on a 32-bit processor based computer , where in
you can address 0 - 4 GB addresses ( i.e. 0 - 2^32 ) .

>
> > 0009fc00-0009ffff : reserved
>
> whats this reserve says and why and for what it is
> reserved?
>

Not sure about this , maybe Intel manual docs will
help you on this .

> > 000a0000-000bffff : Video RAM area
> > 000c0000-000c7fff : Video ROM
>
> why do we need to seprate all these areas?
>

Becoz Video RAM area is read + write capabable area,
but Video ROM is a read only area.


> > 000e0000-000effff : Extension ROM
> > 000f0000-000fffff : System ROM
> > 00100000-1fecffff : System RAM <---- 2
> > 00100000-0028dadf : Kernel code
> > 0028dae0-00324f63 : Kernel data
> > 1fed0000-1feeffff : ACPI Non-volatile Storage
> > 1fef0000-1fefffff : System RAM <---- 3
> > 40000000-40000fff : Intel Corp. 82801BA/BAM/CA/CAM
> > Ethernet Controller
> > 40000000-40000fff : eepro100
> > 40300000-4037ffff : Intel Corp. 82815 CGC [Chipset
> > Graphics Controller]
> > 44000000-47ffffff : Intel Corp. 82815 CGC [Chipset
> > Graphics Controller]
> > feea0000-ffffffff : reserved
> >
> > Are these memory address ranges dynamically
> > determined ? Which kernel code file does this ?
> >
> > Also , does /proc/ioports represent IO-mapped
> > PHYSICAL memory addresses ,
> > similar to the the Memory-mapped PHYSICAL memory
> > addresses in /proc/iomem ?
> >
> > ~> cat /proc/ioports
> > 0000-001f : dma1
> > 0020-003f : pic1
> > 0040-005f : timer
> > 0060-006f : keyboard
> > 0070-007f : rtc
> > 0080-008f : dma page reg
> > 00a0-00bf : pic2
> > 00c0-00df : dma2
> > 00f0-00ff : fpu
> > 0170-0177 : ide1
> > 01f0-01f7 : ide0
> > 02f8-02ff : serial(auto)
> > 0376-0376 : ide1
> > 03c0-03df : vga+
> > 03f6-03f6 : ide0
> > 03f8-03ff : serial(auto)
> > 0cf8-0cff : PCI conf1
> > 1000-103f : Intel Corp. 82801BA/BAM/CA/CAM
> Ethernet
> > Controller
> > 1000-103f : eepro100
> > 2000-20ff : Intel Corp. 82801BA/BAM AC'97 Audio
> > 2000-20ff : Intel 82801BA-ICH2 - AC'97
> > 2400-243f : Intel Corp. 82801BA/BAM AC'97 Audio
> > 2400-243f : Intel 82801BA-ICH2 - Controller
> > 2440-245f : Intel Corp. 82801BA/BAM USB (Hub #2)
> > 2440-245f : usb-uhci
> > 2460-246f : Intel Corp. 82801BA IDE U100
> > 2460-2467 : ide0
> > 2468-246f : ide1
> >
> > > >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 ) .
>
> does it really depend on motherboard? or does it
> depend on the hardwares stuffs we have on system?
>

I think motherboard , since the point to add
additional
H/W is fixed .

Cheers !

> thanks
>
> ankit
>
>
____________________________________________________________ ____________
> Yahoo! Messenger - Communicate instantly..."Ping"
> your friends today! Download Messenger Now
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>





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