insmod: unresolved symbol XIo_In32/XIo_Out32

Juliana Su js084 at
Sat Jul 12 05:11:06 EST 2008


Thanks for your reply! I am new to creating loadable kernel modules, so 
I hope you do not mind some more questions... How can I get the XIo_* 
helper routines to compile into the kernel or export them with 
EXPORT_SYMBOL( )? In my c file (my driver file from which I create the 
object file), I made sure to include xio.h, which is where XIo_In32 and 
XIo_Out32 are defined (see below section from xio.h).

/************************** Function Prototypes 

/* The following functions allow the software to be transportable across
 * processors which may use memory mapped I/O or I/O which is mapped into a
 * seperate address space such as X86.  The functions are better suited for
 * debugging and are therefore the default implementation. Macros can 
 * be used if USE_IO_MACROS is defined.

/* Functions */
u8 XIo_In8(XIo_Address InAddress);
u16 XIo_In16(XIo_Address InAddress);
u32 XIo_In32(XIo_Address InAddress);

void XIo_Out8(XIo_Address OutAddress, u8 Value);
void XIo_Out16(XIo_Address OutAddress, u16 Value);
void XIo_Out32(XIo_Address OutAddress, u32 Value);


/* The following macros allow optimized I/O operations for memory mapped I/O
 * Note that the SYNCHRONIZE_IO may be moved by the compiler during
 * optimization.

#define XIo_In8(InputPtr)  (*(volatile u8  *)(InputPtr)); SYNCHRONIZE_IO;
#define XIo_In16(InputPtr) (*(volatile u16 *)(InputPtr)); SYNCHRONIZE_IO;
#define XIo_In32(InputPtr) (*(volatile u32 *)(InputPtr)); SYNCHRONIZE_IO;

#define XIo_Out8(OutputPtr, Value)  \
    { (*(volatile u8  *)(OutputPtr) = Value); SYNCHRONIZE_IO; }
#define XIo_Out16(OutputPtr, Value) \
    { (*(volatile u16 *)(OutputPtr) = Value); SYNCHRONIZE_IO; }
#define XIo_Out32(OutputPtr, Value) \
    { (*(volatile u32 *)(OutputPtr) = Value); SYNCHRONIZE_IO; }


I thought that, by including xio.h, XIo_In32 and XIo_Out32 would be 
taken care of, but that is probably a novice assumption of mine...


Grant Likely wrote:
> On Fri, Jul 11, 2008 at 10:26:27AM -0400, Juliana Su wrote:
>> Hi,
>> Is anybody familiar with the following error?
>> insmod: unresolved symbol XIo_In32
>> insmod: unresolved symbol XIo_Out32
>> I am trying to write a device driver for a Custom IP and get it to run  
>> on a Xilinx ML310's Linux OS. I am using Xilinx EDK 10.1 and MontaVista  
>> Linux version 2.4.20_mvl31-ml300. I ran into this error when trying to  
>> load my module into the kernel. When I try to load the module using  
>> insmod on the ".o" file, the module refuses to load and gives me the  
>> unresolved symbol error message. I actually stumbled upon an older  
>> posting from June 2006 on this mailing list that described a similar  
>> problem, but those suggestions did not help me. Maybe two years later,  
>> there are more ideas/suggestions/solutions to this problem?
> I can't help much with the 2.4 montavista kernel, but I can say that the
> error means that the XIo_* helper routines are either not compiled into
> the kernel or are not exported with EXPORT_SYMBOL().  The XIo_* routines
> are hooks used by Xilinx cross platform device drivers to make the
> actual accesses to hardware.  If they are not implemented, then you need
> to create them yourself.
> g.

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