diff --git a/drivers/bios_emulator/besys.c b/drivers/bios_emulator/besys.c
index 2a8e1a0..4c4bc8d 100644
--- a/drivers/bios_emulator/besys.c
+++ b/drivers/bios_emulator/besys.c
@@ -49,6 +49,7 @@
 
 #include "biosemui.h"
 
+#if defined(CONFIG_BIOSEMU)
 /*------------------------- Global Variables ------------------------------*/
 
 #ifndef __i386__
@@ -717,3 +718,4 @@
 #endif
 		LOG_outpd(port, val);
 }
+#endif
diff --git a/drivers/bios_emulator/bios.c b/drivers/bios_emulator/bios.c
index ed5437e..7aa1bfb2e 100644
--- a/drivers/bios_emulator/bios.c
+++ b/drivers/bios_emulator/bios.c
@@ -43,6 +43,7 @@
 
 #include "biosemui.h"
 
+#if defined(CONFIG_BIOSEMU)
 /*----------------------------- Implementation ----------------------------*/
 
 /****************************************************************************
@@ -319,3 +320,4 @@
 	bios_intr_tab[0x6D] = int10;
 	X86EMU_setupIntrFuncs(bios_intr_tab);
 }
+#endif
diff --git a/drivers/bios_emulator/biosemu.c b/drivers/bios_emulator/biosemu.c
index 06d4ad3..4c3aedf 100644
--- a/drivers/bios_emulator/biosemu.c
+++ b/drivers/bios_emulator/biosemu.c
@@ -48,6 +48,8 @@
 #include "biosemui.h"
 #include <malloc.h>
 
+#if defined(CONFIG_BIOSEMU)
+
 BE_sysEnv _BE_env = {{0}};
 static X86EMU_memFuncs _BE_mem __attribute__((section(".got2"))) = {
 	BE_rdb,
@@ -368,3 +370,4 @@
 	sregs->gs = M.x86.R_GS;
 	return out->x.ax;
 }
+#endif
diff --git a/drivers/bios_emulator/x86emu/debug.c b/drivers/bios_emulator/x86emu/debug.c
index 0f58a69..915739c 100644
--- a/drivers/bios_emulator/x86emu/debug.c
+++ b/drivers/bios_emulator/x86emu/debug.c
@@ -40,6 +40,8 @@
 #include "x86emu/x86emui.h"
 #include <stdarg.h>
 
+#if defined(CONFIG_BIOSEMU)
+
 /*----------------------------- Implementation ----------------------------*/
 
 #ifdef DEBUG
@@ -459,3 +461,5 @@
 		printk("NC ");
 	printk("\n");
 }
+
+#endif
diff --git a/drivers/bios_emulator/x86emu/decode.c b/drivers/bios_emulator/x86emu/decode.c
index 1e2dcfe..879f0a0 100644
--- a/drivers/bios_emulator/x86emu/decode.c
+++ b/drivers/bios_emulator/x86emu/decode.c
@@ -39,6 +39,8 @@
 
 #include "x86emu/x86emui.h"
 
+#if defined(CONFIG_BIOSEMU)
+
 /*----------------------------- Implementation ----------------------------*/
 
 /****************************************************************************
@@ -1142,3 +1144,5 @@
     return decode_rm01_address(rm);
   return decode_rm10_address(rm);
 }
+
+#endif
diff --git a/drivers/bios_emulator/x86emu/ops.c b/drivers/bios_emulator/x86emu/ops.c
index d1380ce..d334fb5 100644
--- a/drivers/bios_emulator/x86emu/ops.c
+++ b/drivers/bios_emulator/x86emu/ops.c
@@ -76,6 +76,9 @@
 ****************************************************************************/
 
 #include "x86emu/x86emui.h"
+
+#if defined(CONFIG_BIOSEMU)
+
 /*----------------------------- Implementation ----------------------------*/
 
 /* constant arrays to do several instructions in just one function */
@@ -5429,3 +5432,5 @@
 /*  0xfe */ x86emuOp_opcFE_byte_RM,
 /*  0xff */ x86emuOp_opcFF_word_RM,
 };
+
+#endif
diff --git a/drivers/bios_emulator/x86emu/ops2.c b/drivers/bios_emulator/x86emu/ops2.c
index 631a340..81c0d49 100644
--- a/drivers/bios_emulator/x86emu/ops2.c
+++ b/drivers/bios_emulator/x86emu/ops2.c
@@ -46,6 +46,8 @@
 
 #include "x86emu/x86emui.h"
 
+#if defined(CONFIG_BIOSEMU)
+
 /*----------------------------- Implementation ----------------------------*/
 
 /****************************************************************************
@@ -1768,3 +1770,5 @@
 /*  0xfe */ x86emuOp2_illegal_op,
 /*  0xff */ x86emuOp2_illegal_op,
 };
+
+#endif
diff --git a/drivers/bios_emulator/x86emu/prim_ops.c b/drivers/bios_emulator/x86emu/prim_ops.c
index e0827d7..c1152ea 100644
--- a/drivers/bios_emulator/x86emu/prim_ops.c
+++ b/drivers/bios_emulator/x86emu/prim_ops.c
@@ -100,6 +100,8 @@
 #define PRIM_OPS_NO_REDEFINE_ASM
 #include "x86emu/x86emui.h"
 
+#if defined(CONFIG_BIOSEMU)
+
 /*------------------------- Global Variables ------------------------------*/
 
 static u32 x86emu_parity_tab[8] =
@@ -2443,3 +2445,5 @@
     M.x86.R_SP += 4;
     return res;
 }
+
+#endif
diff --git a/drivers/bios_emulator/x86emu/sys.c b/drivers/bios_emulator/x86emu/sys.c
index bb7fcd9..566389f 100644
--- a/drivers/bios_emulator/x86emu/sys.c
+++ b/drivers/bios_emulator/x86emu/sys.c
@@ -41,6 +41,8 @@
 
 #include "x86emu/x86emui.h"
 
+#if defined(CONFIG_BIOSEMU)
+
 /*------------------------- Global Variables ------------------------------*/
 
 X86EMU_sysEnv _X86EMU_env;	/* Global emulator machine state */
@@ -320,3 +322,5 @@
 	M.x86.R_IP = mem_access_word(num * 4);
 	M.x86.intr = 0;
 }
+
+#endif