topic Re: How to force constants in a specific section (MPC5668G with CW10.5) in CodeWarrior Development Tools

How to force constants in a specific section (MPC5668G with CW10.5)

hbouch — Wed, 20 Apr 2016 16:05:37 GMT

Hi,

I'm trying to create a section at a specific address in which I want to put the software version of the application so it can be read back by the bootloader. Here is what I did in the linker script:

MEMORY

{

resetvector: org = 0x00000000, len = 0x00000008

system_cfg: org = 0x00003000, len = 0x00000010

internal_flash: org = 0x00003010, len = 0x000FCFF0

(...)

}

(...)

GROUP: {

.__software_version (CONST) : {}

} > system_cfg

In my code, I have declared the software version constant as follow:

#pragma push

#pragma section R ".__software_version" ".__software_version"

__declspec (section ".__software_version") const uint32_t ESM_ku32NESSoftwareVersion;

#pragma pop

In the linker setting, I put ROM Image Address and RAM Buffer Address of ROM Image at 0x00003010 but the code won't boot. It get stuck in __init_data function. I've also tried to put 0x00003000 but it doesn't even reach the __start function and I get warnings at compilation on ROM image address overlapping other sections.

What am I doing wrong? Can anyone help me please?

Hugo

Re: How to force constants in a specific section (MPC5668G with CW10.5)

TICS_Fiona — Thu, 21 Apr 2016 09:38:46 GMT

Hello Hugo

Could you please replace your code in link command file with this one? And leave the ‘Generate ROM Image’ options with their default settings.

GROUP : {

.__software_version (CONST) LOAD(ADDR(.__software_version)): {}

} > system_cfg

Best Regards

Fiona Kuang

TIC - Technical Information Center

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Re: How to force constants in a specific section (MPC5668G with CW10.5)

hbouch — Thu, 21 Apr 2016 12:13:51 GMT

Hello Fiona,

Thanks for your answer but it didn't solve my problem. However I'm sure of what you mean when you say "eave the ‘Generate ROM Image’ options with their default settings". I assumed 0x00003000. It compiles with the following linker warnings:

"Overlap of the ROM image address of .init section with executable address of .init section."

"Overlap of the ROM image address of .text section with executable address of .text section."

When I look at the .sx file, I see the block at address 0x00003000 but the content is not what I expected. I should see the software version (0x12345678):

S31900003000480000697C6000A6646302007C6001247FE802A6AA

If forgot the initialisation of the constant in my previous post. You should have read:

#pragma push

#pragma section R ".__software_version" ".__software_version"

__declspec (section ".__software_version") const uint32_t ESM_ku32NESSoftwareVersion = 0x12345678;

#pragma pop

Any other ideas?

Re: How to force constants in a specific section (MPC5668G with CW10.5)

hbouch — Mon, 25 Apr 2016 16:04:37 GMT

The ROM Image Address and RAM Buffer Address of ROM Image that should be used is 0x00003010.

Also, to make sure that my constant is in the output file, __declspec(force_export) has to be used in the declaration:

#pragma push

#pragma section R ".__software_version"

__declspec(section ".__software_version") __declspec(force_export) const uint32_t ESM_ku32NESSoftwareVersion = 0x12345678;

#pragma pop

Thanks for you help.

Hugo