linking question

Meshounah · Post by **Meshounah** » Thu Aug 09, 2007 3:46 pm

i'm currently keeping my source in ~/os and i have the following files loader.s, loader.o, kernel.c, kernel.o, and linker.LD but i don't really know how to actually link them together in cygwin. thank you

Alboin · Post by **Alboin** » Thu Aug 09, 2007 3:53 pm

You have to use ld.

It should be something like:

Code: Select all

ld -Tlinker.LD loader.o kernel.o -o kernel.bin

However, forgive me if my syntax is a little off for some reason or another.

Meshounah · Post by **Meshounah** » Thu Aug 09, 2007 3:58 pm

ok i did that but it doesnt work for me:

loader.o: in function 'loader' :
loader.s:<.text+0x14>: undefined reference to 'main'

and now i really don't know whats wrong

Alboin · Post by **Alboin** » Thu Aug 09, 2007 4:10 pm

Try removing the _ from main in kernel.c.

Meshounah · Post by **Meshounah** » Thu Aug 09, 2007 4:14 pm

it didn't work still same thing

AJ · Post by AJ » Fri Aug 10, 2007 2:16 am

Hi,

An objdump of kernel.o shows that your .c function _main is being compiled as __main. Your asm loader is trying to reference _main. Are you sure that removing the leading underscore in the c file only does not work?

Cheers,
Adam

Meshounah · Post by **Meshounah** » Fri Aug 10, 2007 11:23 am

yes it does not work i still get the same error

Meshounah · Post by **Meshounah** » Tue Aug 14, 2007 9:52 am

i tried everything i can think of still same thing

JamesM · Post by **JamesM** » Tue Aug 14, 2007 10:12 am

Do:

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nm main.o                #or whatever your object file is where 'main()' is defined.
nm start.o

And post the results.

JamesM

Meshounah · Post by **Meshounah** » Tue Aug 14, 2007 2:25 pm

Shot at 2007-08-14

Meshounah · Post by **Meshounah** » Tue Aug 14, 2007 2:28 pm

or could you post a barebone c kernel?

Candy · Post by **Candy** » Tue Aug 14, 2007 2:55 pm

Are you using a proper crosscompiler? You appear to call alloca() which you really shouldn't. Also, your compiler appears to prefix underscores which is just bad.

What this reads:

The first file defines _main and requires ___main and __alloca (both of which are nonsense, which is your compiler setup screwing up). The second file defines _loader and requires _main.

Your code is correct. Fix your compilers.

Meshounah · Post by **Meshounah** » Tue Aug 14, 2007 2:59 pm

ok i started with a new barebone kernel and i went nowhere before i had a problem

start.o file not recognized: file format not recognized

Meshounah · Post by **Meshounah** » Tue Aug 14, 2007 3:01 pm

Candy wrote:Are you using a proper crosscompiler? You appear to call alloca() which you really shouldn't. Also, your compiler appears to prefix underscores which is just bad.

What this reads:

The first file defines _main and requires ___main and __alloca (both of which are nonsense, which is your compiler setup screwing up). The second file defines _loader and requires _main.

Your code is correct. Fix your compilers.

how?

also i tried it under linux and cygwin still same thing

Candy · Post by **Candy** » Tue Aug 14, 2007 3:04 pm

http://www.osdev.org/wiki/GCC_Cross-Compiler of course.

Make a cross compiler and it will not pretend you're making a program for Windows.