OSDev.org

Hello.

I try to make my bootloader, but have trouble with data address offset after linking.
Here my wlink config:

If use it, as a result all data addresses in program calculated as offsets from 0000.
If use next:

It only use offset from 0x7c00 for code, but still use offset from 0000 for data.

If use next:

It generates valid program, puts data at offset 0x7d00 and use valid offset, but this version work only if my code < 0x100 byte and use hardcoded offset for data, so that is not good idea.

How I can set wlink to place DATA right after CODE and use global offset 0x7c00?

Far be it from me to discourage you from using your favourite compiler, but Open Watcom is not widely used for OS development, which means that it can be a little difficult - compared to the more popular toolsets - to obtain the relevant information. A starting point is http://wiki.osdev.org/Watcom , but you may need to do further research.

Can you help me find more suitable compiler and linker for this?
I use Watcom because it can without troubles link C with ASM, generate small code and support very old processors as 8086.

I'm afraid I can't make any suggestions as to a good toolkit for 8086 programming. I haven't written anything for it in decades.

Have you tried the Open Watcom forums? You are more likely to find someon who can help you there. (Although I believe that rdos - a user here - is a Watcom fan. Hopefully he will see your post and reply.)