Re: Glibc on ppc built on i386

[Geoff Keating <geoffk@ozemail.com.au>]

> Date: Thu, 26 Nov 1998 13:12:02 +0100
> From: Kenneth Johansson <erakeon@kieray1.p.y.ki.era.ericsson.se>
> 
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> Hi Iam trying to make my own glibc that uses softfloat and no inline
> assembler(FPU) for PPC. As I don't have an ppc machine I can use I
> must make the library on a intel machine.

The usual way to cope with those ppc chips that didn't come with an
FPU is to write an FPU emulator.  If done well, this is faster and
uses less memory than using softfloat, and lets you use precompiled
binaries.  It also has the advantage that I don't think egcs has been
tested with -msoft-float and -fpic together.

If you do want to use soft-float for some reason, you need to write
implementations for the routines that currently use FPU instructions
(setjmp and longjmp, the floating-point environment routines whose
names start with 'f', the math routines written in assembler called
sysdeps/powerpc/s_*.S); move the current versions of these routines
into sysdeps/powerpc/fpu and put your routines in sysdeps/powerpc.
Leave Versions alone, it's harmless if you don't define the routines.
Leave the math routines written in C alone unless you want to rewrite
them to be faster with the emulated library.  Of course, you will also
need a library that implements gcc's soft-float floating point
emulation.

> mmap(0x7ffff7f8, 0, PROT_NONE, 0x4 /* MAP_??? */|MAP_FIXED|MAP_ANONYMOUS|0x1860640, 25560692, 0x1860000) = 0x1800000
> mmap(0x7ffff7f8, 0, PROT_NONE, 0x4 /* MAP_??? */|MAP_FIXED|MAP_ANONYMOUS|0x1860640, 25560692, 0x1860000) = 0x1840000
> --- SIGSEGV (Segmentation fault) ---
> +++ killed by SIGSEGV +++
> bash# 

This could be absolutely anything.

-- 
Geoffrey Keating <geoffk@ozemail.com.au>