README.Porting
author Sam Lantinga <slouken@libsdl.org>
Thu, 16 May 2013 00:43:22 -0700
changeset 7180 3733e68edbc3
parent 6987 7084af936d82
permissions -rw-r--r--
Fixed bug 1846 - _allmul implementation in SDL_stdlib.c doesn't clean up the stack

Colin Barrett

I see this manifest itself (VS2012 x86) as:

"Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention."

in the first call to SDL_GetTicks in my application. The disassembly at the problem line is:

hires_now.QuadPart *= 1000;
00AD0792 push 0
00AD0794 push 3E8h
00AD0799 mov eax,dword ptr [ebp-10h]
00AD079C push eax
00AD079D mov ecx,dword ptr [hires_now]
00AD07A0 push ecx
00AD07A1 call _allmul (0AE7D40h)
00AD07A6 mov dword ptr [hires_now],eax
00AD07A9 mov dword ptr [ebp-10h],edx

Apparently _allmul should be popping the stack but isn't (other similar functions in SDL_stdlib.c - _alldiv and whatnot - DO pop the stack).

A 'ret 10h' at the end of _allmul appears to do the trick
     1 
     2 * Porting To A New Platform
     3 
     4   The first thing you have to do when porting to a new platform, is look at
     5 include/SDL_platform.h and create an entry there for your operating system.
     6 The standard format is __PLATFORM__, where PLATFORM is the name of the OS.
     7 Ideally SDL_platform.h will be able to auto-detect the system it's building
     8 on based on C preprocessor symbols.
     9 
    10 There are two basic ways of building SDL at the moment:
    11 
    12 1. The "UNIX" way:  ./configure; make; make install
    13 
    14    If you have a GNUish system, then you might try this.  Edit configure.in,
    15    take a look at the large section labelled:
    16 	"Set up the configuration based on the target platform!"
    17    Add a section for your platform, and then re-run autogen.sh and build!
    18 
    19 2. Using an IDE:
    20 
    21    If you're using an IDE or other non-configure build system, you'll probably
    22    want to create a custom SDL_config.h for your platform.  Edit SDL_config.h,
    23    add a section for your platform, and create a custom SDL_config_{platform}.h,
    24    based on SDL_config.h.minimal and SDL_config.h.in
    25 
    26    Add the top level include directory to the header search path, and then add
    27    the following sources to the project:
    28 	src/*.c
    29 	src/atomic/*.c
    30 	src/audio/*.c
    31 	src/cpuinfo/*.c
    32 	src/events/*.c
    33 	src/file/*.c
    34 	src/haptic/*.c
    35 	src/joystick/*.c
    36 	src/power/*.c
    37 	src/render/*.c
    38 	src/stdlib/*.c
    39 	src/thread/*.c
    40 	src/timer/*.c
    41 	src/video/*.c
    42 	src/audio/disk/*.c
    43 	src/audio/dummy/*.c
    44 	src/video/dummy/*.c
    45 	src/haptic/dummy/*.c
    46 	src/joystick/dummy/*.c
    47 	src/main/dummy/*.c
    48 	src/thread/generic/*.c
    49 	src/timer/dummy/*.c
    50 	src/loadso/dummy/*.c
    51 
    52 
    53 Once you have a working library without any drivers, you can go back to each
    54 of the major subsystems and start implementing drivers for your platform.
    55 
    56 If you have any questions, don't hesitate to ask on the SDL mailing list:
    57 	http://www.libsdl.org/mailing-list.php
    58 
    59 Enjoy!
    60 	Sam Lantinga				(slouken@libsdl.org)
    61