ARM Linux: Where the SDRAM address and size defined
Hi, In Samsung s3c24xx arch code, I cannot find where the SDRAM address and size information was defined. Can someone give me a lead? Thanks. -woody -- Life is the only flaw in an otherwise perfect nonexistence -- Schopenhauer woody public key at http://subkeys.pgp.net:11371 (narkewoody@gmail.com)
Hello Woody,
On Mon, Mar 7, 2016 at 10:55 AM, Woody Wu <narkewoody@gmail.com> wrote:
Hi,
In Samsung s3c24xx arch code, I cannot find where the SDRAM address and size information was defined. Can someone give me a lead? Thanks.
I will try to answer this.
Its usual practice to have the size of RAM in bootargs in Linux kernel. And I am not sure about the SDRAM address(It may be part of DTSI file).
-woody
-- Life is the only flaw in an otherwise perfect nonexistence -- Schopenhauer
woody public key at http://subkeys.pgp.net:11371 (narkewoody@gmail.com)
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On Mon, Mar 07, 2016 at 01:25:25PM +0800, Woody Wu wrote:
Hi,
Hello,
In Samsung s3c24xx arch code, I cannot find where the SDRAM address and size information was defined. Can someone give me a lead? Thanks.
ARM boards, are now defined using Device Tree (DTS for source, DTB for binary, the compiled form). I couldn't find out for s3c24xx but, the block memory is defined as follow: memory { reg = <0x20000000 0x20000000>; }; (source: arch/arm/boot/dts/sama5dxcm.dtsi)
-woody
-- François
Sent from my iPad
On Mar 7, 2016, at 6:04 PM, fser@code-libre.org wrote:
On Mon, Mar 07, 2016 at 01:25:25PM +0800, Woody Wu wrote: Hi,
Hello,
In Samsung s3c24xx arch code, I cannot find where the SDRAM address and size information was defined. Can someone give me a lead? Thanks.
ARM boards, are now defined using Device Tree (DTS for source, DTB for binary, the compiled form). I couldn't find out for s3c24xx but, the block memory is defined as follow:
memory { reg = <0x20000000 0x20000000>; };
What about boards that is not using DTD? For the DTD based boards like above I also wondering that how to define a board with two SDRAM bands, one is at 0x30000000 - 0x34000000 and another is at 0x38000000 - 0x3C000000, should I put two reg entries in the memory section of the above dtd?
(source: arch/arm/boot/dts/sama5dxcm.dtsi)
-woody
-- François
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On Mon, Mar 7, 2016 at 11:04 AM, <fser@code-libre.org> wrote:
On Mon, Mar 07, 2016 at 01:25:25PM +0800, Woody Wu wrote:
Hi,
Hello,
In Samsung s3c24xx arch code, I cannot find where the SDRAM address and size information was defined. Can someone give me a lead? Thanks.
ARM boards, are now defined using Device Tree (DTS for source, DTB for binary, the compiled form). I couldn't find out for s3c24xx but, the block memory is defined as follow:
memory { reg = <0x20000000 0x20000000>; };
For the record. The memory node in the DTS is most of the time useless / there for documentation since the node is overwritten by the bootloader who is in charge to initialized the DRAM. -- Carlo Caione
participants (4)
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Carlo Caione -
fser＠code-libre.org -
priyaranjan -
Woody Wu