MPC565 assembly in macro #define???

TanKun · ‎04-12-2007

hello ,

i use codewarrior v 5.5.1.1 for a mpc565 and want to define some asm instructions in a macro in a C head file.

the asm instructions look like :

   stwu     AddressInMemory,-80(AddressInMemory)
    stw      r0,8(AddressInMemory)
    mfctr    r0
    stw      r0,12(AddressInMemory)
    mfxer   r0
    stw     r0,16(AddressInMemory)

....

which the parameter AddressInMemory is a pointer in the c program.it can be any addresse in the whole Memory.

i have tried to write the macro like this.

#define portRESTORE_CONTEXT()
{

extern volatile void * aPointer;
asm ("lwz r0,32(%0)":"=g"(aPointer));

...

...
}

it not works.can someone tell me what the right is.

OR,because the assembly instructions are too much, i want write them regularly in a asm file, and define it as a assembly function, which c can also call them in C-function.but the problem is how can i give the "aPointer" of C as parameter to the assembly function,and the parameter will be given as Constant(in other words, the parameter will not use any register,because my intention is all of the contents of registers will be saved in the place where the "aPointer" points.)

thanks for your help.

kun

Message Edited by J2MEJediMaster on 2007-04-12 10:03 AM

marc_paquette · ‎04-12-2007

Like any preprocessor macro, you need to terminate each line of a multi-line macro with a backslash. Try this:

#define portRESTORE_CONTEXT(aPointer) \
    stwu     AddressInMemory,-80(aPointer); \
    stw      r0,8(aPointer); \
    mfctr    r0; \
    stw      r0,12(aPointer); \
    mfxer   r0; \
    stw     r0,16(aPointer)

To invoke the macro, you have a couple of choices:

void f(void* p)
{
/* C statements. */

asm { portRESTORE_CONTEXT(p); }

/* C statements. */
}

or

asm void a(void* p)
{
portRESTORE_CONTEXT(p);
blr;
}

Marc.

MPC565 assembly in macro #define???

MPC565 assembly in macro #define???

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