diff -Naur a/com32/elflink/ldlinux/cli.c b/com32/elflink/ldlinux/cli.c
--- a/com32/elflink/ldlinux/cli.c	2014-10-06 18:27:44.000000000 +0200
+++ b/com32/elflink/ldlinux/cli.c	2026-03-15 16:06:17.717507427 +0100
@@ -125,7 +125,7 @@
 			 int (*pDraw_Menu) (int, int, int),
 			 void (*show_fkey) (int), bool *timedout)
 {
-    char cmdline[MAX_CMDLINE_LEN] = { };
+    static char cmdline[MAX_CMDLINE_LEN] = { };
     int key, len, prev_len, cursor;
     int redraw = 0;
     int x, y;
diff -Naur a/com32/lib/syslinux/debug.c b/com32/lib/syslinux/debug.c
--- a/com32/lib/syslinux/debug.c	2014-10-06 18:27:44.000000000 +0200
+++ b/com32/lib/syslinux/debug.c	2026-03-15 16:05:45.520181343 +0100
@@ -1,6 +1,7 @@
 #include <linux/list.h>
 #include <string.h>
 #include <stdbool.h>
+#include <stdio.h>
 
 #ifdef DYNAMIC_DEBUG
 
diff -Naur a/dos/string.h b/dos/string.h
--- a/dos/string.h	2014-10-06 18:27:44.000000000 +0200
+++ b/dos/string.h	2026-03-15 16:06:39.166724474 +0100
@@ -5,12 +5,21 @@
 #ifndef _STRING_H
 #define _STRING_H
 
+#include <stddef.h>
+
 /* Standard routines */
 #define memcpy(a,b,c)	__builtin_memcpy(a,b,c)
 #define memmove(a,b,c)	__builtin_memmove(a,b,c)
 #define memset(a,b,c)	__builtin_memset(a,b,c)
 #define strcpy(a,b)	__builtin_strcpy(a,b)
-#define strlen(a)	__builtin_strlen(a)
+
+static inline size_t strlen(const char *s)
+{
+    const char *ss = s;
+    while (*ss)
+	ss++;
+    return ss - s;
+}
 
 /* This only returns true or false */
 static inline int memcmp(const void *__m1, const void *__m2, unsigned int __n)
diff -Naur a/extlinux/main.c b/extlinux/main.c
--- a/extlinux/main.c	2014-10-06 18:27:44.000000000 +0200
+++ b/extlinux/main.c	2026-03-15 16:06:27.287604280 +0100
@@ -38,6 +38,7 @@
 #include <sysexits.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <sys/mount.h>
 #include <sys/vfs.h>
diff -Naur a/mk/efi.mk b/mk/efi.mk
--- a/mk/efi.mk	2014-10-06 18:27:44.000000000 +0200
+++ b/mk/efi.mk	2026-03-15 16:06:39.167724484 +0100
@@ -25,6 +25,7 @@
 
 CFLAGS = -I$(EFIINC) -I$(EFIINC)/$(EFI_SUBARCH) \
 		-DEFI_FUNCTION_WRAPPER -fPIC -fshort-wchar -ffreestanding \
+		-fcommon \
 		-Wall -I$(com32)/include -I$(com32)/include/sys \
 		-I$(core)/include -I$(core)/ $(ARCHOPT) \
 		-I$(com32)/lib/ -I$(com32)/libutil/include -std=gnu99 \
diff -Naur a/mk/elf.mk b/mk/elf.mk
--- a/mk/elf.mk	2014-10-06 18:27:44.000000000 +0200
+++ b/mk/elf.mk	2026-03-15 16:06:39.169724504 +0100
@@ -55,6 +55,7 @@
 endif
 
 CFLAGS     = $(GCCOPT) $(GCCWARN) -W -Wall \
+	     -fcommon \
 	     -fomit-frame-pointer -D__COM32__ -D__FIRMWARE_$(FIRMWARE)__ -DDYNAMIC_MODULE \
 	     -nostdinc -iwithprefix include \
 	     -I$(com32)/libutil/include -I$(com32)/include \
diff -Naur a/mk/embedded.mk b/mk/embedded.mk
--- a/mk/embedded.mk	2014-10-06 18:27:44.000000000 +0200
+++ b/mk/embedded.mk	2026-03-15 16:06:39.169724504 +0100
@@ -58,7 +58,7 @@
 LD        += -m elf_$(ARCH)
 
 # Note: use += for CFLAGS and SFLAGS in case something is set in MCONFIG.local
-CFLAGS    += $(GCCOPT) -g $(GCCWARN) -Wno-sign-compare $(OPTFLAGS) $(INCLUDES)
+CFLAGS    += $(GCCOPT) -g $(GCCWARN) -Wno-sign-compare -fcommon $(OPTFLAGS) $(INCLUDES)
 SFLAGS    += $(CFLAGS) -D__ASSEMBLY__
 
 .SUFFIXES: .c .o .S .s .i .elf .com .bin .asm .lst .c32 .lss
diff -Naur a/mk/lib.mk b/mk/lib.mk
--- a/mk/lib.mk	2014-10-06 18:27:44.000000000 +0200
+++ b/mk/lib.mk	2026-03-15 16:09:45.873608721 +0100
@@ -52,7 +52,7 @@
 	    -falign-labels=0 -ffast-math -fomit-frame-pointer
 WARNFLAGS = $(GCCWARN) -Wpointer-arith -Wwrite-strings -Wstrict-prototypes -Winline
 
-CFLAGS  = $(OPTFLAGS) $(REQFLAGS) $(WARNFLAGS) $(LIBFLAGS)
+CFLAGS  = $(OPTFLAGS) $(REQFLAGS) -fcommon $(WARNFLAGS) $(LIBFLAGS)
 
 ifndef EFI_BUILD
 CFLAGS += -mregparm=3 -DREGPARM=3