diff -wpruN '--exclude=*.orig' a~/gdb/features/Makefile a/gdb/features/Makefile
--- a~/gdb/features/Makefile	1970-01-01 00:00:00
+++ a/gdb/features/Makefile	1970-01-01 00:00:00
@@ -99,6 +99,11 @@ OUTPUTS = $(patsubst %,$(outdir)/%.dat,$
 # --enable-targets=all GDB.  You can override this by passing XMLTOC
 # to make on the command line.
 XMLTOC = \
+	i386/amd64-avx-illumos.xml \
+	i386/amd64-illumos.xml \
+	i386/i386-avx-illumos.xml \
+	i386/i386-illumos.xml \
+	i386/i386-mmx-illumos.xml \
 	microblaze-with-stack-protect.xml \
 	microblaze.xml \
 	mips-dsp-linux.xml \
@@ -227,6 +232,8 @@ FEATURE_XMLFILES = aarch64-core.xml \
 	i386/64bit-pkeys.xml \
 	i386/64bit-sse.xml \
 	i386/x32-core.xml \
+	i386/32bit-illumos.xml \
+	i386/64bit-illumos.xml \
 	loongarch/base32.xml \
 	loongarch/base64.xml \
 	riscv/rv32e-xregs.xml \
diff -wpruN '--exclude=*.orig' a~/gdb/features/i386/32bit-illumos.xml a/gdb/features/i386/32bit-illumos.xml
--- a~/gdb/features/i386/32bit-illumos.xml	1970-01-01 00:00:00
+++ a/gdb/features/i386/32bit-illumos.xml	1970-01-01 00:00:00
@@ -0,0 +1,11 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2010-2013 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!DOCTYPE feature SYSTEM "gdb-target.dtd">
+<feature name="org.gnu.gdb.i386.illumos">
+  <reg name="orig_eax" bitsize="32" type="int" regnum="41"/>
+</feature>
diff -wpruN '--exclude=*.orig' a~/gdb/features/i386/64bit-illumos.xml a/gdb/features/i386/64bit-illumos.xml
--- a~/gdb/features/i386/64bit-illumos.xml	1970-01-01 00:00:00
+++ a/gdb/features/i386/64bit-illumos.xml	1970-01-01 00:00:00
@@ -0,0 +1,11 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2010-2013 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!DOCTYPE feature SYSTEM "gdb-target.dtd">
+<feature name="org.gnu.gdb.i386.illumos">
+  <reg name="orig_rax" bitsize="64" type="int" regnum="57"/>
+</feature>
diff -wpruN '--exclude=*.orig' a~/gdb/features/i386/amd64-avx-illumos.xml a/gdb/features/i386/amd64-avx-illumos.xml
--- a~/gdb/features/i386/amd64-avx-illumos.xml	1970-01-01 00:00:00
+++ a/gdb/features/i386/amd64-avx-illumos.xml	1970-01-01 00:00:00
@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2010-2013 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!-- AMD64 with AVX - illumos.  -->
+
+<!DOCTYPE target SYSTEM "gdb-target.dtd">
+<target>
+  <architecture>i386:x86-64</architecture>
+  <osabi>illumos</osabi>
+  <xi:include href="64bit-core.xml"/>
+  <xi:include href="64bit-sse.xml"/>
+  <xi:include href="64bit-illumos.xml"/>
+  <xi:include href="64bit-avx.xml"/>
+</target>
diff -wpruN '--exclude=*.orig' a~/gdb/features/i386/amd64-illumos.xml a/gdb/features/i386/amd64-illumos.xml
--- a~/gdb/features/i386/amd64-illumos.xml	1970-01-01 00:00:00
+++ a/gdb/features/i386/amd64-illumos.xml	1970-01-01 00:00:00
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2010-2013 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!-- AMD64 - illumos.  -->
+
+<!DOCTYPE target SYSTEM "gdb-target.dtd">
+<target>
+  <architecture>i386:x86-64</architecture>
+  <osabi>illumos</osabi>
+  <xi:include href="64bit-core.xml"/>
+  <xi:include href="64bit-sse.xml"/>
+  <xi:include href="64bit-illumos.xml"/>
+</target>
diff -wpruN '--exclude=*.orig' a~/gdb/features/i386/i386-avx-illumos.xml a/gdb/features/i386/i386-avx-illumos.xml
--- a~/gdb/features/i386/i386-avx-illumos.xml	1970-01-01 00:00:00
+++ a/gdb/features/i386/i386-avx-illumos.xml	1970-01-01 00:00:00
@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2010-2013 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!-- I386 with AVX - illumos.  -->
+
+<!DOCTYPE target SYSTEM "gdb-target.dtd">
+<target>
+  <architecture>i386</architecture>
+  <osabi>illumos</osabi>
+  <xi:include href="32bit-core.xml"/>
+  <xi:include href="32bit-sse.xml"/>
+  <xi:include href="32bit-illumos.xml"/>
+  <xi:include href="32bit-avx.xml"/>
+</target>
diff -wpruN '--exclude=*.orig' a~/gdb/features/i386/i386-illumos.xml a/gdb/features/i386/i386-illumos.xml
--- a~/gdb/features/i386/i386-illumos.xml	1970-01-01 00:00:00
+++ a/gdb/features/i386/i386-illumos.xml	1970-01-01 00:00:00
@@ -0,0 +1,17 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2010-2013 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!-- I386 with SSE - illumos.  -->
+
+<!DOCTYPE target SYSTEM "gdb-target.dtd">
+<target>
+  <architecture>i386</architecture>
+  <osabi>illumos</osabi>
+  <xi:include href="32bit-core.xml"/>
+  <xi:include href="32bit-illumos.xml"/>
+  <xi:include href="32bit-sse.xml"/>
+</target>
diff -wpruN '--exclude=*.orig' a~/gdb/features/i386/i386-mmx-illumos.xml a/gdb/features/i386/i386-mmx-illumos.xml
--- a~/gdb/features/i386/i386-mmx-illumos.xml	1970-01-01 00:00:00
+++ a/gdb/features/i386/i386-mmx-illumos.xml	1970-01-01 00:00:00
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2010-2013 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!-- I386 with MMX - illumos.  -->
+
+<!DOCTYPE target SYSTEM "gdb-target.dtd">
+<target>
+  <architecture>i386</architecture>
+  <osabi>illumos</osabi>
+  <xi:include href="32bit-core.xml"/>
+  <xi:include href="32bit-illumos.xml"/>
+</target>