Re: [patch] Re: Linux 2.4.5-ac6

[Maciej W. Rozycki]

On Wed, 6 Jun 2001, Ivan Kokshaysky wrote:

> > No need to patch arch_get_unmapped_area(), but OSF/1 compatibility code
> > might need fixing.  I suppose an OSF/1 binary must have an appropriate
> > flag set in its header after building with the -taso option so that the
> > system knows the binary wants 32-bit addressing.
> 
> I'm not sure if COFF headers have such flag at all. I'll check this.

 Then how does OSF/1, especially the dynamic linker, know if a binary
needs 32-bit addressing?  I suppose we could use the same way of
selection.

 Hmm...:

$ uname -mprsv
OSF1 V4.0 1091 alpha alpha
$ file /usr/bin/X11/real-netscape
/usr/bin/X11/real-netscape:     COFF format alpha dynamically linked,
demand paged executable or object module stripped - version 3.11-8
$ odump -D /usr/bin/X11/real-netscape | grep FLAGS
                       FLAGS: 0x40000001
$ odump -D /usr/bin/X11/xterm | grep FLAGS
                       FLAGS: 0x00000001

A wild guess: the 32-bit flag is bit 30.

 A second attempt (after a bit of searching in /usr/include):

$ grep ADDRESSES /usr/include/elf_mips.h
#define RHF_USE_31BIT_ADDRESSES     0x40000000

Ah, here it is.  Remember OSF/1 was running on MIPS (DECstation) first and
they never used ELF but apparently reused a few of its properties.

 So what is needed is already in place and ready to use.

  Maciej

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: [e-mail], PGP key available        +