diff -ru bdwgc.orig/include/private/gcconfig.h bdwgc/include/private/gcconfig.h
--- bdwgc.orig/include/private/gcconfig.h	2023-02-07 14:35:54.616933050 +0100
+++ bdwgc/include/private/gcconfig.h	2023-02-07 14:41:11.028698667 +0100
@@ -110,6 +110,20 @@
 #   define LINUX
 # endif
 
+# if defined(__midipix__)
+#   define MIDIPIX
+#   include <fcntl.h>
+#   include <sys/select.h>
+
+#   include <psxtypes/psxtypes.h>
+#   include <pemagine/pemagine.h>
+#   include <ntapi/nt_thread.h>
+
+int __gc_data_start_mark__[1];
+int __gc_data_end_mark__[1];
+#endif
+
+
 /* And one for NetBSD: */
 # if defined(__NetBSD__)
 #   define NETBSD
@@ -554,7 +554,7 @@
 #   define mach_type_known
 # elif (defined(__i386__) || defined(i386) || defined(__X86__)) \
        && (defined(ANY_BSD) || defined(DARWIN) || defined(EMBOX) \
-           || defined(LINUX) || defined(QNX))
+           || defined(LINUX) || defined(QNX) || defined(MIDIPIX))
 #   define I386
 #   define mach_type_known
 # elif (defined(__ia64) || defined(__ia64__)) && defined(LINUX)
@@ -607,7 +607,7 @@
 # elif (defined(__x86_64) || defined(__x86_64__) || defined(__amd64__) \
         || defined(__X86_64__)) \
        && (defined(ANY_BSD) || defined(DARWIN) || defined(LINUX) \
-           || defined(QNX))
+           || defined(QNX) || defined(MIDIPIX))
 #   define X86_64
 #   define mach_type_known
 # endif
@@ -1464,6 +1478,13 @@
 #         define SOFT_VDB
 #       endif
 #   endif
+#   ifdef MIDIPIX
+#      define OS_TYPE "MIDIPIX"
+#      define DATASTART   ((ptr_t)__gc_data_start_mark__)
+#      define DATAEND     ((ptr_t)__gc_data_end_mark__)
+#      define STACKBOTTOM (ptr_t)(((nt_tib *)pe_get_teb_address())->stack_base)
+#      define USE_MMAP_ANON
+#   endif
 #   ifdef CYGWIN32
 #       define WOW64_THREAD_CONTEXT_WORKAROUND
 #       define DATASTART ((ptr_t)GC_DATASTART)  /* From gc.h */
@@ -2259,6 +2280,13 @@
 #         define SOFT_VDB
 #       endif
 #   endif
+#   ifdef MIDIPIX
+#       define OS_TYPE "MIDIPIX"
+#       define DATASTART   ((ptr_t)__gc_data_start_mark__)
+#       define DATAEND     ((ptr_t)__gc_data_end_mark__)
+#       define STACKBOTTOM (ptr_t)(((nt_tib *)pe_get_teb_address())->stack_base)
+#       define USE_MMAP_ANON
+#   endif
 #   ifdef DARWIN
 #     define DARWIN_DONT_PARSE_STACK 1
 #     define STACKBOTTOM ((ptr_t)0x7fff5fc00000)
@@ -2676,7 +2676,7 @@
 #if defined(AIX) || defined(ANY_BSD) || defined(BSD) || defined(DARWIN) \
     || defined(DGUX) || defined(HAIKU) || defined(HPUX) || defined(HURD) \
     || defined(IRIX5) || defined(LINUX) || defined(OSF1) || defined(QNX) \
-    || defined(SVR4)
+    || defined(SVR4) || defined(MIDIPIX)
 # define UNIX_LIKE      /* Basic Unix-like system calls work.   */
 #endif