long outport help [FIXED]

GLneo · **Joined:** Wed Dec 20, 2006 7:56 pm **Posts:** 237

hi all,

In the OSWIKI thing , says:

Quote:

the functions sysOutLong and sysInLong are assembly language functions that make use of the OUTL and INPL Pentium assembly language instructions.

but i can't figure out how to write them, i've tried:

Code:

inline unsigned int inportl(unsigned int port)
{
    unsigned int result;
    asm volatile("inl %1, %0" : "=a" (result) : "dN" (port));
    return result;
}

inline void outportl(unsigned int port, unsigned int data)
{
    asm volatile("outl %1, %0" : : "dN" (port), "a" (data));
}

but it says:

Quote:

Error: suffix of operand invaled for "out"

thx!

Brynet-Inc · **Posted:** Wed Feb 07, 2007 6:22 pm

Code:

inline unsigned long inportl(unsigned short port)
{
   unsigned long result;
   __asm__ __volatile__("inl %%dx, %%eax" : "=a" (result) : "dN" (port));
   return result;
}

inline void outportl(unsigned short port, unsigned long data)
{
   __asm__ __volatile__("outl %%eax, %%dx" : : "d" (port), "a" (data));
}

This should be adequate..

GLneo · **Joined:** Wed Dec 20, 2006 7:56 pm **Posts:** 237

that worked!, thx!, but what was i doing wrong?

Brynet-Inc · **Posted:** Wed Feb 07, 2007 6:48 pm

GLneo wrote:

that worked!, thx!, but what was i doing wrong?

I attached a unified patch... It should outline the changes I made

Combuster · **Posted:** Thu Feb 08, 2007 1:54 am

As if a diff would explain the difference between correct and broken code...

What you did was suggesting gcc to fill in the most optimizer-effective registers it could spare (using %1, %0). However, inports and outports work only with one pair of registers: DX and AL/AX/EAX. Since you didnt tell it, it'd try to fill in some random register which would obviously fail the assembly stage.

OSDev.org

long outport help [FIXED]

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