[gentoo-embedded] new ARM920T based computer design (EP9315)

[gentoo-embedded] new ARM920T based computer design (EP9315)

[Heath Holcomb]

I'm a hardware engineer (BS in Electronics Engineering, Texas A&M) and I did 
the x86 how-to for embedded gentoo.  I've got a new project at my work, to 
design a ARM based SBC (single board computer) for our main product.  I'll 
actually be doing the schematic entry and PCB layout.

The specific part is Cirrus Logic EP9315, it's an ARM920T based chip.  It has 
the SDRAM interface, flash interface (NOR), MAC (not PHY), and an MMU.

Any advice on this chip or any ARM would be nice.  I plan on use embedded 
Gentoo as the base of our OS.  The development board comes with CE 5.0 and 
Linux (Debian based).  There is a lot of unknowns (how does Linux fit onto 
the NOR flash, what about the file system, etc...), so any help would be 
appreciated if anyone has done this before.

I'll also be adding a section to the how-to that deals with ARM based devices.

-- 
heath holcomb
liquidcable at bulah.com
www.bulah.com
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Re: [gentoo-embedded] new ARM920T based computer design (EP9315)

[wireless]

Heath Holcomb wrote:
> I'm a hardware engineer (BS in Electronics Engineering, Texas A&M) and I did 
> the x86 how-to for embedded gentoo.  I've got a new project at my work, to 
> design a ARM based SBC (single board computer) for our main product.  I'll 
> actually be doing the schematic entry and PCB layout.
> 
> The specific part is Cirrus Logic EP9315, it's an ARM920T based chip.  It has 
> the SDRAM interface, flash interface (NOR), MAC (not PHY), and an MMU.
> 
> Any advice on this chip or any ARM would be nice.  I plan on use embedded 
> Gentoo as the base of our OS.  The development board comes with CE 5.0 and 
> Linux (Debian based).  There is a lot of unknowns (how does Linux fit onto 
> the NOR flash, what about the file system, etc...), so any help would be 
> appreciated if anyone has done this before.
> 
> I'll also be adding a section to the how-to that deals with ARM based devices.


JTAG is always nice. SD/SmartMedia/CompactFlash  is cool.
What's the specific purpose of the board? What kind of product,
or just an embedded board to sell to others?


James



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Re: [gentoo-embedded] new ARM920T based computer design (EP9315)

[KIMURA Masaru / hiyuh]

On 20:42 Fri 27 Jan     , Heath Holcomb wrote:
> The specific part is Cirrus Logic EP9315, it's an ARM920T based chip.  It has 
> the SDRAM interface, flash interface (NOR), MAC (not PHY), and an MMU.
(SNIP)
> Any advice on this chip or any ARM would be nice.  I plan on use embedded 
> Gentoo as the base of our OS.  The development board comes with CE 5.0 and 
> Linux (Debian based).  There is a lot of unknowns (how does Linux fit onto 
> the NOR flash, what about the file system, etc...), so any help would be 
> appreciated if anyone has done this before.
Yeah, it's nice.
I'm playing with other EP9315 SBC, too. (a.k.a Armadillo-9)
http://armadillo.atmark-techno.com/armadillo-9
Unfortunately, it has only Japanese web pages.
But, this corporation published by some English PDF specification or so.
http://download.atmark-techno.com/armadillo-9/doc/armadillo9_hardware_manual_en-1.0.2.pdf
http://download.atmark-techno.com/armadillo-9/doc/armadillo9_software_manual_en-1.0.2.pdf

BTW, GAO Engineering provides like that SBC.
It's in "Enbedded Linux Boards" category in http://www.gaoengineering.com

And then, as you know,
"Unofficial Linux 2.6.x support for Cirrus EP93xx processors homepage" is.
http://members.inode.at/m.burian/ep93xx/

> I'll also be adding a section to the how-to that deals with ARM based devices.
It would be nice.
I had my EP9315 SBC runs with Gentoo.
But now, it has GNU glibc based userland.
I'll play to uClibc based Gentoo on it.
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Re: [gentoo-embedded] new ARM920T based computer design (EP9315)

[Heath Holcomb]

On Monday 30 January 2006 03:22, KIMURA Masaru / hiyuh wrote:
> On 20:42 Fri 27 Jan     , Heath Holcomb wrote:
> > The specific part is Cirrus Logic EP9315, it's an ARM920T based chip.  It
> > has the SDRAM interface, flash interface (NOR), MAC (not PHY), and an
> > MMU.
>
> (SNIP)
>
> > Any advice on this chip or any ARM would be nice.  I plan on use embedded
> > Gentoo as the base of our OS.  The development board comes with CE 5.0
> > and Linux (Debian based).  There is a lot of unknowns (how does Linux fit
> > onto the NOR flash, what about the file system, etc...), so any help
> > would be appreciated if anyone has done this before.
>
> Yeah, it's nice.
> I'm playing with other EP9315 SBC, too. (a.k.a Armadillo-9)
> http://armadillo.atmark-techno.com/armadillo-9
> Unfortunately, it has only Japanese web pages.
> But, this corporation published by some English PDF specification or so.
> http://download.atmark-techno.com/armadillo-9/doc/armadillo9_hardware_manua
>l_en-1.0.2.pdf
> http://download.atmark-techno.com/armadillo-9/doc/armadillo9_software_manua
>l_en-1.0.2.pdf
>
> BTW, GAO Engineering provides like that SBC.
> It's in "Enbedded Linux Boards" category in http://www.gaoengineering.com
>
> And then, as you know,
> "Unofficial Linux 2.6.x support for Cirrus EP93xx processors homepage" is.
> http://members.inode.at/m.burian/ep93xx/
>
> > I'll also be adding a section to the how-to that deals with ARM based
> > devices.
>
> It would be nice.
> I had my EP9315 SBC runs with Gentoo.
> But now, it has GNU glibc based userland.
> I'll play to uClibc based Gentoo on it.

Thanks for the links!  It looks like the stock 2.6.x kernel does not work 
fully with the EP93xx chips, right?

Do you know anything about running the kernel out of NOR flash?  I ask because 
NOR flash can execute out of inself, instead of having to copy the kernel to 
RAM and run from RAM.  This makes boot times faster, but NOR flash does not 
support filing systems the way NAND flash does (think compact flash, 
usbsticks, etc..).


-- 
heath holcomb
liquidcable at bulah.com
www.bulah.com
-- 
gentoo-embedded@gentoo.org mailing list

Re: [gentoo-embedded] new ARM920T based computer design (EP9315)

[KIMURA Masaru / hiyuh]

On 08:31 Mon 30 Jan     , Heath Holcomb wrote:
(SNIP)
> Thanks for the links!  It looks like the stock 2.6.x kernel does not work 
> fully with the EP93xx chips, right?
IIRC, it is NOT official 2.6.x kernel as its name is.
Official linux-2.6.15 tarball shows that, it has NO arch/arm/march-ep93xx or so.
So, it means you needs EP93xx patches or so, maybe.

About Armadillo-9, it has 2.6.x and 2.4.x kernel sources.
http://download.atmark-techno.com/armadillo-9/source/
And almost it seems work fine for the SBC's specification said.

And then, some EP93xx chips has Maverick Crunch FPU.
I want to this FPU to compute some mathematical operations.
But now, it's PITA for me.
Because, for support this FPU, it needs official GNU gcc version 4.0.2 or so.
Otherwise, some hacks are required.
http://yann.poupet.free.fr/ep93xx/

> Do you know anything about running the kernel out of NOR flash?  I ask because 
> NOR flash can execute out of inself, instead of having to copy the kernel to 
> RAM and run from RAM.  This makes boot times faster, but NOR flash does not 
> support filing systems the way NAND flash does (think compact flash, 
> usbsticks, etc..). 
I'm not familir with the features of difference of between NOR and NAND flash.
And then, Armadillo-9 can select which it boots from CF or its flash.
Mine boots from MicroDrive via CF interface at the moment.
After it boot, it can use USB. But it can not boots from USB stick, I heard.

IMHO, to make boot time faster depends on boot loader and/or init script
rather than kernel.
Armadillo-9 has hermit-at as bootloader which is branched from hermit
and shoehorn as kernel parameters setting app.
sys-apps/baselayout-lite in portage tree would be nice for tweaking init
script, maybe.
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