Where does gcc look for include files?

stf92 · 06-02-2013, 01:16 AM

I have this source:

Code:

semoi@server:~/z80_p4/juan$ head -n30 p1.c
   /* Compile con 'gcc -O2 [-ggdb] -o setuid setuid.c'.
    
    * PROG APPL: transmit a .z80 file to the z80. File length supposed to
    * be < 65536 bytes.    
    * Se transmite primero la longitud del archivo (2 bytes), que
    * el programa obtiene por su cuenta. Luego el archivo y, 
    * finalmente, dos bytes de checksum que incluyen los dos bytes
    * de la longitud. Al transmitir el archivo, se descartan los
    * 10 primeros bytes, que son el header del z80.
    *
    * NOTA: en una nueva version de monitor, el programa en ROM que
    * contiene el modulo que carga el archivo transmitido en RAM,
    * podria leer el noveno y decimo byte, que contiene la direccion
    * de carga y no habria necesidad de cargarla a mano. 
    */         
    
   

   #define _XOPEN_SOURCE 500   // for usleep
   
   #include <stdlib.h>	      // for EXIT_SUCCESS constant
   #include <stdio.h>
   #include <sys/types.h>
   #include <sys/stat.h>
   #include <unistd.h>        // includes usleep as well
   #include <asm/io.h>        // for outb

   unsigned char msk_data= 0x02;
   unsigned char msk_clock= 0x01;
   unsigned char image;

But I get

Code:

semoi@server:~/z80_p4/juan$ gcc -O2 -o p1 p1.c
p1.c:26:42: fatal error: asm/io.h: No such file or directory
compilation terminated.

This is slackware 14.0 x86_64. Where should asm/io.h be?

dwhitney67 · 06-02-2013, 05:08 AM

If you have not done so already, you will need to install the Kernel Header Files for your particular kernel. I'm not familiar with Slackware, so I cannot advise you on how to go about doing this.

Typically the asm directory, containing io.h, is located in the following area (again, this may not apply to Slackware):

Code:

/lib/modules/`uname -r`/build/include

P.S. You may also have a link to io.h in /usr/include/sys

stf92 · 06-02-2013, 06:04 AM

Thank you very much. What much disconcerts me is that, in slackware 12.0, locate does not find a single 'asm/io.h' instance. However, the program compiles well there.