Hello,
I'm using u-boot 1.3.0 from the latest FreeScale Linux BSP MPC8313E-RDB.
If I set TEXT_BASE = 0x1000000, so I could use BDI debugger to load into RAM
and run it out of RAM.
I'm ABLE to ping to the host from u-boot
But, if I set TEXT_BASE=0xFE000000, and burn the image it into Flash,
recycle the power to run it out of Flash.
I'm NOT able to ping from u-boot with error message
"No link".
When I change TEXT_BASE from 0x1000000 to 0xFE000000, I have to do "make
clean" before "make", otherwise it have error message
" undefined reference to 'env_name_space'"
On the other direction, when I change TEXT_BASE from 0xFE000000 to
0x1000000, I have successful compilation without "make clean", but the
u-boot hangs at "DRAM". I have to do "make clean" for successful u-boot AND
network access.
I really appreciate your time and help.
Regards,
Duy-Ky
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Sent: Thursday, November 06, 2008 5:00 PM
Subject: Linuxppc-embedded Digest, Vol 51, Issue 9
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Today's Topics:
1. Using DMA ([EMAIL PROTECTED])
2. Re: Using DMA (Scott Wood)
3. Re: Using DMA (Bill Gatliff)
4. Re: Using DMA ([EMAIL PROTECTED])
5. Re: Using DMA (Bill Gatliff)
----------------------------------------------------------------------
Message: 1
Date: Wed, 5 Nov 2008 18:07:20 -0800
From: [EMAIL PROTECTED]
Subject: Using DMA
To: [email protected]
Message-ID:
<[EMAIL PROTECTED]>
Content-Type: text/plain; charset="US-ASCII"
This may be the wrong forum for this question. If so I apologize, and
could someone please tell me the appropriate place to ask?
Assuming this is the right place, I'm working with the 2.6.27 (stable)
kernel and an MPC8347E processor. I'm using a custom NAND controller and
a custom driver to talk with that controller. I'm now to the point where
I'm trying to optimize/improve performance and something I'd like to do is
set up the driver to use DMA transfers to the controller. (As an
additional bit of info, I modeled my driver on the Cafe driver.) However,
no one here has ever had to set up DMA from scratch before, it's always
been done by an existing driver or the kernel, so I'm in uncharted
teritory.
In the Cafe driver, Linux Device Drivers 3rd Edition, and DMA-mapping.txt
everyone talks about how to allocate buffers using
dma/pci_alloc_coherent(), but no one talks about how to actually use it.
I'm pretty sure (even in my ignorance) that just allocating a DMA coherent
buffer and then copying in and out of it does NOT actually engage the
underlying hardware and perform a DMA transfer.
With some digging I've found the Freescale Elo/Elo Plus DMA driver which
supports my processor. What I'm not clear on is how to actually make use
of it. How do I tie my NAND driver to the Freescale DMA driver and
actually get the hardware to work? Any pointers are greatly appreciated.
Thanks.
Bruce
------------------------------
Message: 2
Date: Thu, 06 Nov 2008 12:29:38 -0600
From: Scott Wood <[EMAIL PROTECTED]>
Subject: Re: Using DMA
To: [EMAIL PROTECTED]
Cc: [email protected]
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=UTF-8; format=flowed
[EMAIL PROTECTED] wrote:
In the Cafe driver, Linux Device Drivers 3rd Edition, and DMA-mapping.txt
everyone talks about how to allocate buffers using
dma/pci_alloc_coherent(), but no one talks about how to actually use it.
I'm pretty sure (even in my ignorance) that just allocating a DMA
coherent
buffer and then copying in and out of it does NOT actually engage the
underlying hardware and perform a DMA transfer.
Generally, you program the device itself to peform the transfer. I'm
assuming that your custom NAND controller can't do DMA by itself, though.
With some digging I've found the Freescale Elo/Elo Plus DMA driver which
supports my processor. What I'm not clear on is how to actually make use
of it. How do I tie my NAND driver to the Freescale DMA driver and
actually get the hardware to work? Any pointers are greatly appreciated.
Tell the DMA controller where to move data from, and where to move it to.
-Scott
------------------------------
Message: 3
Date: Thu, 06 Nov 2008 12:36:58 -0600
From: Bill Gatliff <[EMAIL PROTECTED]>
Subject: Re: Using DMA
To: Scott Wood <[EMAIL PROTECTED]>
Cc: [EMAIL PROTECTED], [email protected]
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=ISO-8859-1
Scott Wood wrote:
[EMAIL PROTECTED] wrote:
In the Cafe driver, Linux Device Drivers 3rd Edition, and
DMA-mapping.txt everyone talks about how to allocate buffers using
dma/pci_alloc_coherent(), but no one talks about how to actually use
it. I'm pretty sure (even in my ignorance) that just allocating a DMA
coherent buffer and then copying in and out of it does NOT actually
engage the underlying hardware and perform a DMA transfer.
Does the "adma" stuff address this any?
b.g.
--
Bill Gatliff
[EMAIL PROTECTED]
------------------------------
Message: 4
Date: Thu, 6 Nov 2008 12:58:53 -0800
From: [EMAIL PROTECTED]
Subject: Re: Using DMA
To: Bill Gatliff <[EMAIL PROTECTED]>
Cc: Scott Wood <[EMAIL PROTECTED]>, [email protected]
Message-ID:
<[EMAIL PROTECTED]>
Content-Type: text/plain; charset="US-ASCII"
Bill Gatliff <[EMAIL PROTECTED]> wrote on 11/06/2008 10:36:58 AM:
Scott Wood wrote:
> [EMAIL PROTECTED] wrote:
>> In the Cafe driver, Linux Device Drivers 3rd Edition, and
>> DMA-mapping.txt everyone talks about how to allocate buffers using
>> dma/pci_alloc_coherent(), but no one talks about how to actually use
>> it. I'm pretty sure (even in my ignorance) that just allocating a DMA
>> coherent buffer and then copying in and out of it does NOT actually
>> engage the underlying hardware and perform a DMA transfer.
Does the "adma" stuff address this any?
What is "adma"?
Bruce
------------------------------
Message: 5
Date: Thu, 06 Nov 2008 15:42:17 -0600
From: Bill Gatliff <[EMAIL PROTECTED]>
Subject: Re: Using DMA
To: [EMAIL PROTECTED]
Cc: Scott Wood <[EMAIL PROTECTED]>, [email protected]
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=ISO-8859-1
[EMAIL PROTECTED] wrote:
Bill Gatliff <[EMAIL PROTECTED]> wrote on 11/06/2008 10:36:58 AM:
Scott Wood wrote:
[EMAIL PROTECTED] wrote:
In the Cafe driver, Linux Device Drivers 3rd Edition, and
DMA-mapping.txt everyone talks about how to allocate buffers using
dma/pci_alloc_coherent(), but no one talks about how to actually use
it. I'm pretty sure (even in my ignorance) that just allocating a DMA
coherent buffer and then copying in and out of it does NOT actually
engage the underlying hardware and perform a DMA transfer.
Does the "adma" stuff address this any?
What is "adma"?
Bruce
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Asynchronous DMA. See this paper, for example:
http://www.power.org/devcon/07/Session_Downloads/PADC07_Aytac_Haluk_09_13_07_layout_FINAL.pdf
It looks like the structure of interest is async_tx_submit. Beyond
that, I can't offer much because I haven't used it.
b.g.
--
Bill Gatliff
[EMAIL PROTECTED]
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