Build binary file with MinGw32

[gedeon]

I try build binary file with MinGw32 but i have 2 problems

- ld seems doesn't work with the -e xxx option
- and the binary file produced is finaly not a binary file , it's a win 32 file

i use this 2 commande lines :
gcc -c -o ./gdos/kernel/kernel.o ./gdos/kernel/kernel.c
   ld -o ./gdos/bin/kernel.bin -e main --format=binary ./gdos/kernel/kernel.o

i have this result :
ld: warning: cannot find the entry symbol main; defaulting to 00030000

Is someone have a solution ?

[Tim]

- ld seems doesn't work with the -e xxx option

Try -e _main.

- and the binary file produced is finaly not a binary file , it's a win 32 file

Try the -b or --format option. Alternatively, link to PE format, then use objcopy to convert to binary.

[gedeon]

i already tried _main it was the same

and with other format pe-i386 or elf32-386 i have undefined reference to _alloca and __main

i'm tired of this tools that never work

Maybe i could try cygwin but i'm afraid that was the same problem

[Tim]

The _alloca/__main problem is easy.

Calls to _alloca are inserted by gcc on Windows for functions whose local variables are bigger than 4096 bytes; it should generally be possible to avoid this. gcc also inserts a call to __main at the beginning of main; it's OK to write your own version of __main which doesn't do anything.

If you decide you do want _alloca, link against libgcc.a, which should have been provided with gcc.

[gedeon]

thanks

step by step ....

Now i have a new problem (another one)

i want to use libgcc.a with this command line :

ld -e _main -Ttext 0x030000 -b pe-i386 ./gdos/kernel/kernel.o -L ./gdos/lib -l libgcc.a

and the result is ......

l: cannot find -llibgcc.a

so the path is the good one and the file libgcc.a is present in the directory

so what the matter ?

i also tried with -l ./gdos/lib/gcclib.a but the error message is the same

[Tim]

I had to use a command line like this:
[tt]-lgcc -L/lib/gcc-lib/i686-pc-cygwin/3.2[/tt]

I use gcc 3.2 on Cygwin, so this is the right path for me.

[gedeon]

To be sure i have reintalled Cygwin on cdrive, it was on e drive

i have no command like lgcc

but when i try tris command in my makefile

ld -e _main -Ttext 0x030000 -b pe-i386 ./gdos/kernel/kernel.o -L\lib\gcc-lib\i686-pc-cygwin\3.3.1

its the same result and i don't understand
the only differnece is the gcc version

[Tim]

OK, maybe I haven't been 100% clear.

Here is the actual command I use to link things.
[tt]ld -o ../../../distrib/tetris.exe \
objects/tetris.o \
../../../lib/crt0.o ../../../lib/framebuf_user.lib ../../../lib/libc.lib ../../../lib/libsys.lib \
-lgcc -L/lib/gcc-lib/i686-pc-cygwin/3.2[/tt]

Modify this as appropriate for your build system.

[gedeon]

thanks for your help and for your patience, it works !

PS : there is few documentation on -lgcc ( or lc )