The source now "works" on both OSX and Linux.

runtime/Makefile

@@ -1,7 +1,7 @@
 
 CFLAGS = -I/opt/local/include -Wall -DNDEBUG -O3
 #CFLAGS = -Wall -g
-LDFLAGS = -L/opt/local/lib -g -ldl -lgmp -dynamic
+LDFLAGS = -L/opt/local/lib -g -ldl -lgmp -rdynamic
 CC = gcc
 all: ikarus
 
@@ -49,4 +49,4 @@ ikarus.h: ikarus-data.h
 	touch ikarus.h
 
 clean:
-	rm -f *.o ikarus
+	rm -f *.o 

runtime/ikarus-enter.s

@@ -1,10 +1,14 @@
 
 .text
+.globl ik_asm_enter
 .globl _ik_asm_enter
 .globl ik_underflow_handler
+.globl ik_foreign_call
 .globl _ik_foreign_call
+.globl ik_asm_reenter
 .globl _ik_asm_reenter
 .align 8
+ik_asm_enter:
 _ik_asm_enter:
   # ignored value is the third arg 12(%esp)
   # code is the second arg  8(%esp)
@@ -50,6 +54,7 @@ L_multivalue_underflow:
   jmp L_do_underflow
 
 .align 8
+ik_asm_reenter:
 _ik_asm_reenter:
   # argc is at 12(%esp)
   # scheme stack is third arg   8(%esp)
@@ -74,6 +79,7 @@ L_multi_reentry:
 
 
 .align 8
+ik_foreign_call:
 _ik_foreign_call:
   movl %esp, 8(%esi)     # (movl fpr (pcb-ref 'frame-pointer))
   movl %ebp, 0(%esi)     # (movl apr (pcb-ref 'allocation-pointer))

runtime/ikarus-fasl.c

@@ -13,6 +13,9 @@
 #include <sys/mman.h>
 #include <dlfcn.h>
 
+#ifndef RTLD_DEFAULT
+#define RTLD_DEFAULT 0
+#endif
 
 typedef struct {
   char* membase;