i.MX ProcessorsのトピックRe: How to link code to DDR (start address 0x80000000) on Cortex M4 side in IMX7D

How to link code to DDR (start address 0x80000000) on Cortex M4 side in IMX7D

chandiniindavar — Mon, 14 Aug 2017 09:17:01 GMT

I have modified "MCIMX7D_M4_ddr.ld " as follow

MEMORY
{
      m_interrupts (RX) : ORIGIN = 0x80000000, LENGTH = 0x00000240
      m_text (RX) : ORIGIN = 0x80000240, LENGTH = 0x0001FFFF
      m_data (RW) : ORIGIN = 0x20210000, LENGTH = 0x00010000
}

there is no error when I compile the code, but the process can not start up when I load the binary file to 0x80000000 on uboot. I load file as follow:

tftp 0x80000000 example.bin;

dcache flush;

bootaux 0x80000000

M4 core starts up and i can see my starting printf in M4 terminal

i did change imx7d-sdb.dts and imx7d-sdb-m4.dts

Changed from 0x80000000 to 0x80100000 in both files

in imx7d-sdb.dts

memory {
reg = <0x80100000 0x80000000>;
};

in imx7d-sdb-m4.dts:

memory {
linux,usable-memory = <0x80100000 0x1ff00000>,
<0xa0000000 0x1ff00000>;

But linux hangs here

** Unable to read file boot.scr **
reading zImage
6619128 bytes read in 326 ms (19.4 MiB/s)
Booting from mmc ...
reading imx7d-sdb-m4.dtb
46439 bytes read in 35 ms (1.3 MiB/s)
Kernel image @ 0x80800000 [ 0x000000 - 0x64fff8 ]
## Flattened Device Tree blob at 83000000
Booting using the fdt blob at 0x83000000
Using Device Tree in place at 83000000, end 8300e566

Starting kernel ...

Could anyone please what changes i have to do to USE starting of DDR for only M4 ? any disable linux access to that memory ?

Thank you in advance

Chandini

Re: How to link code to DDR (start address 0x80000000) on Cortex M4 side in IMX7D

Carlos_Musich — Wed, 23 Aug 2017 20:54:09 GMT

Hi Chandini,

IMX6SX provides also Cortex-M4 as IMX7D does. The following document will be useful:

http://www.nxp.com/docs/en/application-note/AN5127.pdf

For further details please provide information details about how are you developing M4 application. What compiler are you using, which IDE, is it based on an example application?

Regards,
Carlos

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Re: How to link code to DDR (start address 0x80000000) on Cortex M4 side in IMX7D

ryanschaefer — Thu, 24 Aug 2017 21:29:18 GMT

Hi Chandini,

Please refer to my similar question here:

https://community.nxp.com/message/921361

Re: How to link code to DDR (start address 0x80000000) on Cortex M4 side in IMX7D

chandiniindavar — Mon, 04 Sep 2017 14:59:57 GMT

Thanks Ryan and Carlos .