Why does my build of hello_world does not run on M4?

[fbre]

Hi,

Situation:

1. I've downloaded SDK_2.5.0_EVK-MIMX8MM.tar.gz from https://mcuxpresso.nxp.com/en/select
2. extracted it on an Ubuntu PC
3. went to boards/evkmimx8mm/demo_apps/hello_world/armgcc and ran ./build_all.sh  (just for trying the given examples)
4. copied the following files from Ubuntu PC to SD card:
   1. armgcc/ddr_release/hello_world.bin   ==>  hello_world_ddrrelease.bin
   2. armgcc/release/hello_world.bin ==> hello_world_release.bin
5. Put the SD card into the i.MX8 Mini Eval Board and booted from SD card. Stopped UBoot booting by keypress and went to the UBoot shell this way
6. typed there in the UBoot shell:
   • fatload mmc 0:1 0x80000000 hello_world_ddrrelease.bin
   • bootaux 0x80000000
7. But I cannot see the "hello world." banner on the M4 console window!
8. If I switch off/on the eval board and try it again with the other compiled file called hello_world_release.bin, it works well and I can see the "hello world." banner on the M4 console window:
   1. fatload mmc 0:1 0x7e0000 hello_world_release.bin
   2. bootaux 0x7e0000

I thought 0x80000000 is the right thing for running the DDR RAM version, just following the ideas of page 19 and 20 of docs/Getting Started with MCUXpresso SDK for i.MX 8M Mini.pdf.

How do I run the DDR RAM version correctly?

Thanks in advance for your help.

[fbre]

aaah, you can delete this post, if you want. I found the solution on page 19.

For the DDR RAM build target, I need also to call dcache flush:

• fatload mmc 0:1 0x80000000 hello_world_ddrrelease.bin
• dcache flush
• bootaux 0x80000000

I wonder why, could you explain, please? And could you also explain what the build target flash_release is for!? Thanx in advance again.

[CarlosCasillas]

Hi,

For Flash targets of the SDK, you could refer to section 7 “Run a flash target demo” of the “Getting Started with MCUXpresso SDK for i.MX 8M Mini” document.

Hope this will be useful for you.

Best regards!

/Carlos