In article <200412292151.iBTLpGUq011152@ector.cs.purdue.edu> you write:
>I found this comment in /usr/src/sys/compat/ibcs2/ibcs2_exec_elf32.c:
>
> * The SCO compiler adds the string "SCO" to the .notes section of all
> * binaries I've seen so far.
>
>It seems to be there:
>
>$ readelf -x 14 wc       
>
>Hex dump of section '.note':
>  0x00000000 004f4353 00000001 0000000c 00000004 ............SCO.
>  0x00000010          00010000 00000003 00010001 ............

Hmm.  I note that ibcs2_exec_elf32.c contains:

#define SCO_SIGNATURE	"\004\0\0\0\014\0\0\0\001\0\0\0SCO\0"

which I don't think matches yours.  I think the signature-matching code
needs to be made a little more relaxed, so that it only matches the name and
perhaps the type, but ignores the desc (including its length).  It should
also really be looking for PT_NOTE in the program headers rather than
SHT_NOTE in the section headers, but this is less important.

Here's an utterly untested and rather grotty patch that might help:

--- ibcs2_exec_elf32.c.~1.8.~	Wed Nov  5 19:43:34 2003
+++ ibcs2_exec_elf32.c	Wed Dec 29 22:40:38 2004
@@ -97,16 +97,20 @@
 
 	for (i = 0; i < eh->e_shnum; i++) {
 		Elf32_Shdr *s = &sh[i];
+		Elf32_Nhdr *np;
+
 		if (s->sh_type != SHT_NOTE ||
 		    s->sh_flags != 0 ||
-		    s->sh_size < sizeof(signature) - 1)
+		    s->sh_size < sizeof(Elf32_Nhdr) + 4)
 			continue;
 
 		if ((error = exec_read_from(p, epp->ep_vp, s->sh_offset,
buf,
-		    sizeof(signature) - 1)) != 0)
+		    sizeof(Elf32_Nhdr) + 4)) != 0)
 			goto out;
 
-		if (memcmp(buf, signature, sizeof(signature) - 1) == 0)
+		np = buf;
+		if (np->n_namesz == 4 && np->n_type == 1 &&
+		    memcmp((caddr_t)(np + 1), "SCO", 4) == 0)
 			goto out;
 		else
 			break;	/* only one .note section so quit */

>Maybe there's a bug in the ibcs2 elf recognition?  Hmm - is there any way
>to exec a file and force a specified emulation to be used, just to see if
>it works right that way?

There's an ELF note documented to do this at
<http://www.netbsd.org/Documentation/kernel/elf-notes.html>, but I can't
find any code to support this in the kernel.

-- 
Ben Harris                                                   <bjh21@NetBSD.org>
Portmaster, NetBSD/acorn26           <URL:http://www.NetBSD.org/Ports/acorn26/>