> The definition of "struct ecoff_symhdr" seems to be missing.  There's
> a definition in /sys/arch/alpha/include/ecoff_machdep.h but I have no
> idea if that definition is appropriate for netbsd-pmax.

I've seen this one as well.  I first just copied the structure
definitions from alpha to make it compile at all, but looking
at the Ultrix equivalents indicates that the structs should be
a bit different.  Here's the diff I'm using now, but beware that
this is a bit of guesswork; I haven't tested it at all:

--- src/sys/arch/mips/include/ecoff_machdep.h.orig	Sat May 24 13:19:56 1997
+++ src/sys/arch/mips/include/ecoff_machdep.h	Sun May 25 15:58:22 1997
@@ -47,3 +47,40 @@
 
 extern void	cpu_exec_ecoff_setregs __P((
     struct proc *, struct exec_package *, u_long, register_t *));
+
+struct ecoff_symhdr {
+	int16_t		magic;
+	int16_t		vstamp;
+	int32_t		lineMax;
+	int32_t		linesize;
+	int32_t		cbLineOffset;
+	int32_t		densenumMax;
+	int32_t		cbDnOffset;
+	int32_t		procMax;
+	int32_t		cbPdOffset;
+	int32_t		lsymMax;
+	int32_t		cbSymOffset;
+	int32_t		optsymMax;
+	int32_t		cbOptOffset;
+	int32_t		auxsymMax;
+	int32_t		cbAuxOffset;
+	int32_t		lstrMax;
+	int32_t		cbSsOffset;
+	int32_t		estrMax;
+	int32_t		cbSsExtOffset;
+	int32_t		fdMax;
+	int32_t		cbFdOffset;
+	int32_t		rfdMax;
+	int32_t		cbRfdOffset;
+	int32_t		esymMax;
+	int32_t		cbExtOffset;
+};
+
+struct ecoff_extsym {
+	int32_t		es_strindex;
+	int32_t		es_value;
+	unsigned	es_type:6;
+	unsigned	es_class:5;
+	unsigned	:1;
+	unsigned	es_symauxindex:20;
+};