storing factory data when programing the mcu

Thanks.

It did the job of storing the _MachineFactoryData[2048] = {5} ; at the correct place and with the correct values (5 at the first element and the rest with zeros).

For the second array, it kept it with 0xffffffff, and did not initiate the array to zeros, but that is only for the test of placing data in the flash memory and it is even better that way.

I hope there will be no difference when I will change the array to a structure of the factory data.

About not defining the location for the factory data, I understand that probably I will never erase it but I figured that I want to keep the 1KB alignment anyway.

I have looked at the map produced by link the arrays are at the correct place in the memory and they have the correct size as well.

Thanks again,

Asi.

Hi Robert,

I have another question that maybe you encouter and know how to deal with, The reason that I need the const array in the flash is to store the "factory" data. My intention was to create a struct that contain all the information (this sturct can contain other structs as well) and to program it to the flash memory. But when I try to do it I get this error message:

#28 expression must have a constant value

when I try to enter a struct to the factory data structure.

And it doesn't matter what I try, I cant manage to set the data to the flash.

Do you have any insights about it?

Thanks again,

Asi.

Is there a way to store

Asi Lazar said:

#28 expression must have a constant value

when I try to enter a struct to the factory data structure.

And it doesn't matter what I try, I cant manage to set the data to the flash.

The error message is fairly self contained.  The expression must be a compile time constant, it cannot contain variables or function calls.  The compiler must be able to determine the value while compiling.

If that still doesn't make sense, reduce the initialization to the smallest piece that shows the problem and let us take a look at it.

Robert

Hi,

Here is an example of my problem:

where I define a basic structure and than when I try to enter it to another structure I get the error.

// the basic structure

typedef struct
{
    int32_t A;
    int32_t B;
}
BasicStruct;

// the structure with a structure in it:

typedef struct
{
	BasicStruct s;
}
SturctOfStruct;

const BasicStruct bs = { 5,10};

const SturctOfStruct st =
{
		bs,
};

when I try to do it I get the " error #28: expression must have a constant value ".

I actually found a way to overcome it if I will write it this way:

const SturctOfStruct st =
{
		{ 5,10},
};

I found it only after adding the post here, and I still hope there is a more elegant way to do it.
Thanks again,

Asi.

Asi Lazar said:

where I define a basic structure and than when I try to enter it to another structure I get the error.

Asi Lazar said:

const BasicStruct bs = { 5,10}; const SturctOfStruct st = { bs, };

You get the error since bs is a variable not a constant.  A const variable is not a constant (at least in C).

You could use a pointer to a structure rather than a structure but I think that will make things too complex in your case since updating now requires walking the structure tree.

typedef struct
{
	BasicStruct *s;
}
SturctOfStruct;
const BasicStruct bs = { 5,10};

const SturctOfStruct st =
{
		&bs,
};

Robert

It will be too complex...

I guess I will stick to the "ugly" way of just writing the values I want in the sturct...

Thanks for all the help.

Asi.

Glad I could help.  This is one of the areas of the language that is more usually noticed by embedded programmers.

Another thing to consider is making an application specific code generator for the factory default structure init.  You can set up the data in a more friendly form (such as a csv file with labels) and generate the initialization data with that.  Languages like AWK and PERL (or even, uggh,  vbscript) allow you to put something together pretty quickly.

Robert