CODEWITHSUNDEEP
carrays
mosmo
mosmo

Reputation: 459

Setting the starting memory address of a 2d array in C?

I have a 2 dimensional array of structures, like so:

struct foo {
    int bar;
    float baz;
};

I'm actually learning about OS development right now, and one thing I'm trying to do is created a 2d array of these structures with the dimensions 80x25:

struct foo foobar[80][25];

Though I need to set it to the address 0xb8000, since this is where the video memory starts. Is there any way I can specify the address in which my array starts?

So far I have tried doing this:

struct foo foobar[80][25];
*foobar = (struct foo) 0xb8000;

But this doesn't work. Edit: also, is doing something like this legal and/or possible to the c99 standard?

Upvotes: 0

Views: 128

Answers (1)

Cecilio Pardo
Cecilio Pardo

Reputation: 1717

You cannot declare array at a specific location, but you can use a pointer:

struct foo *x;
x = (struct foo*)0xb8000;

This should work, but probably the operating system will complain if you tried that from a normal program, unless it is DOS or something like that.

Upvotes: 1

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