Reply by rtstofer May 5, 20112011-05-05
--- In l..., "Donald H" wrote:
>
> --- In l..., "rtstofer" wrote:
> >
> >
> >
> > --- In l..., renjith ks wrote:
> > >
> > > Can I use the SDCard or a USB Flash drive as a virtual RAM?
> > > At first I googled it and I think it is possible with PCs now.
> > > Waiting for the valid suggestions.
> > >
> >
> > Of course it will work. My Win 7 machine uses a Compact Flash as a cache.
>
> Wow, it would seem to me that this would be slow to program and have a limited life !
>
> Does this really work on a daily basis ?
> What Win 7 machine are you using ?
>
> Wouldn't real RAM be better for this type of thing ?
> A Win 7 64-bit machine with lots of GBs of RAM would be far faster/cheaper and more reliable, right ?
>
> don
>

The machine is a very fast quad core 8 thread super whiz-bang PC with SATA drives in a RAID 1 configuration and many GB of RAM.

However, Microsoft now has what they call ReadyBoost as yet another cache of the disk system:

http://en.wikipedia.org/wiki/ReadyBoost

I haven't studied the efficacy of the setup, I just plugged in a CF and Win 7 did the rest. In fact, Win 7 recommended the setup during setup.

Note in the Wikipedia article that Microsoft wants to expand the concept to use spare RAM on other networked machines.

It's not just that HDDs are slow (relatively) but they also have a constrained path and are essentially serial devices. The only way to get some speed is to add parallel drives like this ReadyBoost cache setup.

Richard

An Engineer's Guide to the LPC2100 Series

Reply by capiman26061973 May 5, 20112011-05-05
--- In l..., "Donald H" wrote:
>
> --- In l..., "rtstofer" wrote:
> >
> >
> >
> > --- In l..., renjith ks wrote:
> > >
> > > Can I use the SDCard or a USB Flash drive as a virtual RAM?
> > > At first I googled it and I think it is possible with PCs now.
> > > Waiting for the valid suggestions.
> > >
> >
> > Of course it will work. My Win 7 machine uses a Compact Flash as a cache.
>
> Wow, it would seem to me that this would be slow to program and have a limited life !
>
> Does this really work on a daily basis ?
> What Win 7 machine are you using ?

Have a look at this:

http://en.wikipedia.org/wiki/ReadyBoost

Best regards,

Martin

Reply by Triffid Hunter May 5, 20112011-05-05
On Thu, May 5, 2011 at 9:12 PM, renjith ks wrote:

> Can I use the SDCard or a USB Flash drive as a virtual RAM?
> At first I googled it and I think it is possible with PCs now.
> Waiting for the valid suggestions.
>

Any reason you can't set it up as disk swap?
Reply by Donald H May 5, 20112011-05-05
--- In l..., "rtstofer" wrote:
>
> --- In l..., renjith ks wrote:
> >
> > Can I use the SDCard or a USB Flash drive as a virtual RAM?
> > At first I googled it and I think it is possible with PCs now.
> > Waiting for the valid suggestions.
> > Of course it will work. My Win 7 machine uses a Compact Flash as a cache.

Wow, it would seem to me that this would be slow to program and have a limited life !

Does this really work on a daily basis ?
What Win 7 machine are you using ?

Wouldn't real RAM be better for this type of thing ?
A Win 7 64-bit machine with lots of GBs of RAM would be far faster/cheaper and more reliable, right ?

don

Reply by rtstofer May 5, 20112011-05-05
--- In l..., renjith ks wrote:
>
> Can I use the SDCard or a USB Flash drive as a virtual RAM?
> At first I googled it and I think it is possible with PCs now.
> Waiting for the valid suggestions.
>

Of course it will work. My Win 7 machine uses a Compact Flash as a cache.

It might be better to use an ARM9 with the MMU (Memory Management Unit) to implement virtual memory. There are a lot of Linux ports running on ARM9s. There are also uCLinux implementations which don't require the MMU running on ARM7s.

http://www.uclinux.org/pub/uClinux/ports/arm7tdmi/

Creating a virtual memory system from scratch might be a lot of work. Older computers such as the IBM 1130 implemented it at a trivial level by having features such as LOCAL (Load On Call) and SOCAL (System Load On Call) where a fixed chunk of memory was set aside for transient code and there was a modest scheduler that loaded the area with subroutines retrieved from disk as they were called, This all ran well in a machine with as little as 4k words. It was up to the user to specify which routines would be overlayed.

Richard

Reply by Jean-Jacques Dauchot May 5, 20112011-05-05
try

l...

regards

Jean-Jacques
--- In l..., renjith ks wrote:
>
> Can I use the SDCard or a USB Flash drive as a virtual RAM?
> At first I googled it and I think it is possible with PCs now.
> Waiting for the valid suggestions.
>

Reply by renjith ks May 5, 20112011-05-05
Can I use the SDCard or a USB Flash drive as a virtual RAM?
At first I googled it and I think it is possible with PCs now.
Waiting for the valid suggestions.
Reply by nxp_marketing_usa April 22, 20112011-04-22
--- In l..., jtd wrote:
>
> On Friday 22 April 2011 16:46:47 Wouter van Ooijen wrote:
>
> > On 22/4/2011 7:34 AM, renjith_rohin wrote:
> > > Dear all,
> > > I am new on porting linux to arm.i want to port the linux kernel
> > > to ARM platform ,but i don't know how to begin.I am having an
> > > embedded kit in which ARM7TDMI-S(philips LPC 2362) is the
> > > core.But I think i am having only 128 kB on-chip flash and 32KB
> > > SRAM on LPC2362.Is it enough
> >
> > 128k flash / 32k RAM won't do for Linux. Think more like 64M RAM.
>
> 4Mb flash and 2mb ram with xip uClinux.
>
> > Flash is less of an issue because you can use USB stick or SD card.
> > You won't find this amount of memory on a single-chip uC. Better
> > look at a board-level solution. I love my FriendlyARM SDK board:
> > http://www.friendlyarm.net/products/micro2440 I payed E 120 for a
> > Linux/Android/WinCE board with graphic+touchschreen. ~ E 60 for a
> > serial-line only board.
> --
> Rgds
> JTD
>

You should start at www.LPCLinux.com for Linux or uCLinux. You can also check out Rowebots for a small Linux port.
http://www.rowebots.com/embedded_processors_supported/arm_cortex_m3_nxp_1700

Gene

Reply by jtd April 22, 20112011-04-22
On Friday 22 April 2011 16:46:47 Wouter van Ooijen wrote:

> On 22/4/2011 7:34 AM, renjith_rohin wrote:
> > Dear all,
> > I am new on porting linux to arm.i want to port the linux kernel
> > to ARM platform ,but i don't know how to begin.I am having an
> > embedded kit in which ARM7TDMI-S(philips LPC 2362) is the
> > core.But I think i am having only 128 kB on-chip flash and 32KB
> > SRAM on LPC2362.Is it enough
>
> 128k flash / 32k RAM won't do for Linux. Think more like 64M RAM.

4Mb flash and 2mb ram with xip uClinux.

> Flash is less of an issue because you can use USB stick or SD card.
> You won't find this amount of memory on a single-chip uC. Better
> look at a board-level solution. I love my FriendlyARM SDK board:
> http://www.friendlyarm.net/products/micro2440 I payed E 120 for a
> Linux/Android/WinCE board with graphic+touchschreen. ~ E 60 for a
> serial-line only board.
--
Rgds
JTD
Reply by rtstofer April 22, 20112011-04-22
--- In l..., Wouter van Ooijen wrote:
>
> On 22/4/2011 7:34 AM, renjith_rohin wrote:
> > Dear all,
> > I am new on porting linux to arm.i want to port the linux kernel to ARM
> > platform ,but i don't know how to begin.I am having an embedded kit in
> > which ARM7TDMI-S(philips LPC 2362) is the core.But I think i am having
> > only 128 kB on-chip flash and 32KB SRAM on LPC2362.Is it enough
>

You will probably want to move to an ARM9 chip as the ARM7s don't have the memory management unit (MMU). If you don't want to go that far, you MIGHT be able to port uClinux (a derivative of Linux) as it doesn't require an MMU.

The Hammer is a pretty small platform that supports full Linux:
http://tincantools.com/

The gumstix is another:
http://gumstix.com/

Sparkfun has boards like:
http://www.sparkfun.com/products/9047

Here is an app note on porting uClinux to the LPC22xx series of ARM7 devices:
http://ics.nxp.com/support/documents/microcontrollers/pdf/an10389.pdf

The Blackfin BF537 Stamp is a very fast 16 bit uClinux board:
https://docs.blackfin.uclinux.org/doku.php?id=hw:boards:bf537-stamp

Google for 'ARM9 Linux' for more

Richard