OSDev.org

I'm making a small Pmode kernel, and I can't seem to be able to link a compiled C file with a compiled ASM file!

What I am trying to do is have my ASM file be the 'start' of the kernel. inside the asm file, it calls a function from the C file.

I can't get them to link right. Here is my ASM code:

EXTERN _test

call _test
jmp $ ;hang

There is my C file:

void test() {
//Code Here
}

I am compiling the c file like this : gcc -O3 -c kernel_c.c
I am compiling the ASM like this: NASM -f obj kernel.asm

I am linking them with jloc like this: JLOC kernel.ld kernel.bin

The linker control file (kernel.ld) looks like this:
ALL:

kernel.obj
kernel_c.o
START: 0,0FF800000
,,code,,kernel.obj
CODE: 0
,,code
DATA: 0,#10
,,data
BSS: 0,#10
,,bss

(BTW, this is a Protected Mode Kernel loaded from the bootf02 bootstrap)

What am I doing wrong here? When I try to link it, it tells me that there are 'overlapping chunks' and 'unable to assign section for: ALL, kernel.obj, _NASMDEFSEG'

How do I link a C and an ASM file together and have the ASM file be the beginning of the kernel?

Me to i'm searching for that and no body want to anser me !!!

you do this, and you won't need a asm file

// C module
asm( "jmp test" );

test()
{
// code

while ( 1 )
;
}

aouch! i dunno anything about JLOc, but you're trying to mix OBJ (16 bits format) with gcc output (32 bits format !!) thus nothing good can result of this %-?

i strongly recommend you select a 32 bits format like ELF, COFF with your asm file...

Try using the follwoing command line:

[pre]
>ld my_asm.o my_kernel_in_c.o -o kernel.bin -oformat binary -Ttext 0x100000[/pre]

Note that your start asm file should come first.

I want to say that obj can be 32 bit...

Ive been trying to use Borland C++ builder compiler and Watcom C++ as I realy dislike the DJGPP syntax and...

I like it to be ANSI. Ive tryed the 2 compilers with ELINK as I couldnt figgure out how to use JLOC. ELINK works fine for ONE obj... problem was that I never got to print a whole word on the screen.. it always printed 1 character(with proper colour and backcolour) when it didnt print 1 char it printed thi: "ooooooooo" and thats all

eventually I gave up cuz I had school... couldnt afford the time

now I got back to work but in a diff domain... Im working on a GUI... and Im writting it in boralnd C++(dos 16 bit) and I wrote a class to emulate a video driver using BGI(dont have time to write an actual video driver but I still need to keep the code modular so I can change the commpiler to 32 bit ansi and actual video driver)

Ill as well design a file system soon... on the lines of HPFS but with higher capacity... and wont be compatible with HPFS...

now I need some help I need to be able to compile my ANSI C++ code and link it and be able to load it..

Im asking for experience/help on a compiler like BC++B or Watcom C++ and how to use JLOC properly and efficiently

thanks.. let me know what you think