Installing gcc as a cross-compiler

A guide for an i686-pentium host and powerpc-linux target with altivec support

INDEX

1. Introduction.

2. Preparing the installation

Select a target

• powerpc-linux: PowerPC based systems running linux OS and using Glibc runtime library
  
• powerpc-elf: PowerPC big endian mode running System V.4
• powerpc-eabi: Embedded PowerPC in big endian mode using Newlib runtime library
  
• powerpc-eabisim: Embedded powerpc systems in big endian mode for use under PSIM/GDB simulator.
• powerpc-eabialtivec: Embedded PowerPC with big endian mode using Newlib and automatic setting of altivec gcc switches.
• powerpc-eabisimaltivec:
  
• powerpc-linux-gnualtivec: PowerPC running linux  and automatic setting of -maltivec and -mabi=altivec gcc switches.
  

Suggested directories

3. Required packages

4.  Building binutils

5. Building a bootstrap gcc

6. Building the Linux kernel

7. Building the runtime library.

7.1 For Glibc: systems running linux

7.2 Newlibs: embedded systems or cross-compiling for emulation in GDB

8. Building the final gcc cross-compiler

9. Build the debugger

10. Using gcc with altivec extensions

#include <stdio.h>
#include <altivec.h>
         
     vector signed long vec_2sComp (vector signed long x);
         
     void main ()
     {
        vector signed long v1 = {-2,0,2,8};
        vector signed long v2;
	
        v2 = vec_2sComp (v1);
	
        printf ("Numbers  %9.8vld\n", v1);
        printf ("2's Comp %9.8vld\n", v2);
     }
         
         
     vector signed long vec_2sComp (vector signed long x)
     {
        vector signed long one = {1,1,1,1};
        x = vec_nor (x, x);
        x = vec_add (x, one);
        return x;
     }

Compiling altivec programs

#include <altivec.h>

• Vector constants are done with braces {0,0,0,0} not with parentheses
  

• Vector initializers require no casts if the vector constant is of the same type as the variable it is initializing
  

• Vector initializers for constants require explicit declaration

  vector signed long one = (vector signed long) {1,1,1,1};

      vector signed long one = (vector signed long) {1}; generate an internal compiler error (gcc-3.3.1 bug) 

11. References

GCC

Altivec