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 How do i get my kernel to load binary programs? 
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Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: How do i get my kernel to load binary programs?
well I have to understand more about your kernel to fix it...

On the linker settings on Turbo C++ I removed using the standard library and now it gives me linker errors because it can't find some functions... where would I find the specs to make my own standard library?


Tue Oct 06, 2009 9:07 pm
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Post Re: How do i get my kernel to load binary programs?
pure experence
show me the linker errors
also try putting this at the top of your file
Code:
unsigned EXIT,_EXIT,_NFILE,_LKV=~0;


Tue Oct 06, 2009 9:10 pm

Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: How do i get my kernel to load binary programs?
I can't copy and paste cause I am interneting on a minilaptop and using an old pentium 75 for Turbo C

but I get undefined symbols in module c0.ASM
which are:
__stklen
__nfile
_exit
__exit

the source code is just an empty main
Code:
void main(void) {
   return;
}


Tue Oct 06, 2009 9:25 pm
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Post Re: How do i get my kernel to load binary programs?
put this at the top of your file
Code:
unsigned _stklen=32767,_nfile=1,exit=0,_exit=0,__exit=0;

that should fix them pesky linker errors (i always hated tlink)
i'v used turbo C++ for 2.5 years and GCC for 9 months
and here is the code that overwrites the kernel
Code:
char kernel_execute(char *file){
kernel_print("\r\nExecuting program : ");
kernel_print(file);
FILE *f;
   char*buff;
   char*prog;
   int len;
   int skew;
   char test[10];

   // for some reason TC won't let me allocate
   // much more then 60000
   buff = (char *) malloc(1023);
   if (buff == NULL) return FALSE;
   skew = 256 - FP_OFF(buff);
   prog = buff + skew;
   kernel_print("\r\nBuffer = ");
   kernel_print(itoa(FP_SEG(prog), buff, 16));
   kernel_print(":");
   kernel_print(itoa(FP_OFF(prog), buff, 16));
   f = fopen(file, "r");
   if(f == NULL){free(buff); return FALSE;}
   len = ____len(f);
   kernel_print("\r\nSizeof=");
   kernel_print(itoa(len, test, 10));
   kernel_print("\r\n");
   kernel_print("LBA=");
   kernel_print(itoa(f->sector, test, 10));
   kernel_print("\r\n");
   fread(prog, 1, len, f);
   fclose(f);
   for(int h = 0;h < len;h++){
   kernel_print(itoa(prog[h], test, 16));
   kernel_print(" ");
   }
   read_keyboard();
   asm { CALL prog; };
   return TRUE;
}


Tue Oct 06, 2009 9:31 pm

Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: How do i get my kernel to load binary programs?
it got rid of the linker errors, the resulting .EXE went down from 4k down to 2k but it doesn't execute well, it writes a bunch of letter 'A's on the screen... tracing it dirty, I can see that it still calls a bunch of DOS INTs, it first gets the DOS version number, then it gets the interrupt vectors for INTs 0, 4, 5, 6... sets up its own handler for INT 0... and a bunch of other stuff calling INT 21h

I am gonna pause for today...
but the question is how do I make it stop calling INT 21h????
for a program that does nothing why the obsession with INT 21h


Tue Oct 06, 2009 10:24 pm
Profile
Post Re: How do i get my kernel to load binary programs?
are you using tlink ?
if so compile with Turbo C but do not link
then link with tlink /n <input>, <output>


Tue Oct 06, 2009 10:54 pm

Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: How do i get my kernel to load binary programs?
:o WOW, fucking WOW, yea I got to curse because thats the only way to describe the emphasis of the WOWness, I don't care if there are young children reading this but this WOW needs a curse word to do it justice!

I could have used your insite a couple months back... you would have saved me many hours...

basically yes, it worked,... I was spoiled by the IDE I suppose,...

Code:
tcc -c test.c       <- compiled to obj
tlink /n test.obj   <- compiled to EXE with a no stack warning
exe2bin test.exe    <- turned it into a  .BIN file
td test.bin         <- traced it and the code reflects the source


I'll spend the rest of the week re-writing the Year1OS using this method... hopefully I'll have something done today that addresses your situation...

:?: Question :?:
is there a way to add a code stub? because test.bin assumed to be called by somebody else, I guess its cause main() is a function... I guess I could just paste an assembly stub to make it work but there should be a way in tc. If I do this
Code:
tlink /n /t test.obj
to link it as a .COM directly tlink complains about there not being an appropiate entry point.


Wed Oct 07, 2009 10:44 am
Profile
Post Re: How do i get my kernel to load binary programs?
you need a call program
Code:
.MODEL TINY
ORG 100h
.CODE
extrn main:far
GO:
jmp _main
END GO

tasm call.asm
tlink /n /t call+test, test.bin


Wed Oct 07, 2009 12:12 pm
Post Re: How do i get my kernel to load binary programs?
WAIT!
the above code is wrong and may not assemble or link
also compile with -mt and -c flags
Code:
.MODEL TINY
.CODE
org 100h
.DATA
.DATA?
DGROUP GROUP _DATA,_BSS
.CODE
extrn _main:far
GO:
mov ax,cs
mov ss,ax
mov ds,ax
assume ds:DGROUP
mov DGROUP@,ax
jmp _main
public DGROUP@
DGROUP@ dw 0
END GO


Wed Oct 07, 2009 12:19 pm

Joined: Sat Jul 25, 2009 9:15 am
Posts: 257
Post Re: How do i get my kernel to load binary programs?
you have a JMP _main instead of a CALL _main how does that work?
I'm gonna go play with it soon...


Wed Oct 07, 2009 1:15 pm
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