[Mingw-users] Linking 16-bit code is broken

[Brian P. <br...@sg...>]

Hi
 
(I don't know if this actually made it to the list, so I am sending it
again. If it did just ignore this message)
 
I am writing a boot manager named FreeLoader. Since it is a boot manager
I have to write some 16-bit code to init protected mode so Mingw32
compiled code can run. I link it to an executable .exe file and the run
"objcopy -O binary" to generate the flat binary file. This works great
under all versions of gcc that I have tested (DJGPP, Linux gcc) except
for Mingw32. The problem is that it seems to be fixing up the 16-bit
addresses incorrectly. For example, in the latest FreeLoader code from
cvs I have a 16-bit function called switch_to_prot(). In the map file it
lists this function (correctly) as 0x832f. In the resulting binary file
(after the objcopy) when I step through it with bochs it is actually
calling 0x832d, which is the wrong address. Can anyone tell me how to go
about fixing this in my code or can anyone here fix it in Mingw32?
 
One other problem I have is that when I write functions with large
amounts of local variables the compiler generates code to call a
function named _alloca(). Is there some sort of compiler flag to turn
this off?
 
Thanks
Brian