diff --git a/Makefile b/Makefile
index 4062d2c..5e7d2cc 100644
--- a/Makefile
+++ b/Makefile
@@ -1,17 +1,12 @@
 # Versioning information
 #
-VERSION := v3.0.3
+VERSION := v3.0.4
 WIMBOOT_VERSION := v2.8.0
 SBAT_GENERATION := 1
 
 # Abstract target-independent objects
 #
-OBJECTS := prefix.o startup.o callback.o main.o vsprintf.o string.o peloader.o
-OBJECTS += int13.o vdisk.o cpio.o stdio.o die.o efi.o efimain.o
-OBJECTS += efifile.o efiboot.o efiblock.o cmdline.o
-OBJECTS += cookie.o paging.o memmap.o
-OBJECTS += reg.o charset.o bcd.o fsuuid.o gpt.o msdos.o
-OBJECTS += biosdisk.o efidisk.o payload.o
+OBJECTS := prefix.o
 
 # Target-dependent objects
 #
@@ -20,6 +15,11 @@ OBJECTS_x86_64 := $(patsubst %.o,%.x86_64.o,$(OBJECTS))
 OBJECTS_i386_x86_64 := $(patsubst %.o,%.i386.x86_64.o,$(OBJECTS))
 OBJECTS_arm64 := $(patsubst %.o,%.arm64.o,$(OBJECTS))
 
+include posix/build.mk
+include libnt/build.mk
+include disk/build.mk
+include kern/build.mk
+
 # Header files
 #
 HEADERS := $(wildcard *.h)
@@ -311,6 +311,7 @@ regview : utils/regview.c
 # Cleanup
 
 clean :
+	$(RM) -f $(RM_FILES)
 	$(RM) -f *.s *.o *.a *.elf *.map
 	$(RM) -f elf2efi32 elf2efi64
 	$(RM) -f regview regview.exe
diff --git a/biosdisk.c b/disk/biosdisk.c
similarity index 100%
rename from biosdisk.c
rename to disk/biosdisk.c
diff --git a/disk/build.mk b/disk/build.mk
new file mode 100644
index 0000000..2286cbf
--- /dev/null
+++ b/disk/build.mk
@@ -0,0 +1,16 @@
+# Objects
+OBJ_DISK := disk/biosdisk.o
+OBJ_DISK += disk/efidisk.o
+OBJ_DISK += disk/fsuuid.o
+OBJ_DISK += disk/gpt.o
+OBJ_DISK += disk/msdos.o
+
+OBJECTS += $(OBJ_DISK)
+
+OBJECTS_i386 += $(patsubst %.o,%.i386.o,$(OBJ_DISK))
+OBJECTS_x86_64 += $(patsubst %.o,%.x86_64.o,$(OBJ_DISK))
+OBJECTS_i386_x86_64 += $(patsubst %.o,%.i386.x86_64.o,$(OBJ_DISK))
+OBJECTS_arm64 += $(patsubst %.o,%.arm64.o,$(OBJ_DISK))
+
+RM_FILES += disk/*.s disk/*.o
+
diff --git a/efidisk.c b/disk/efidisk.c
similarity index 100%
rename from efidisk.c
rename to disk/efidisk.c
diff --git a/fsuuid.c b/disk/fsuuid.c
similarity index 100%
rename from fsuuid.c
rename to disk/fsuuid.c
diff --git a/gpt.c b/disk/gpt.c
similarity index 100%
rename from gpt.c
rename to disk/gpt.c
diff --git a/msdos.c b/disk/msdos.c
similarity index 100%
rename from msdos.c
rename to disk/msdos.c
diff --git a/include/memmap.h b/include/e820.h
similarity index 96%
rename from include/memmap.h
rename to include/e820.h
index 72a3bd5..8cd9df0 100644
--- a/include/memmap.h
+++ b/include/e820.h
@@ -1,5 +1,5 @@
-#ifndef _MEMMAP_H
-#define _MEMMAP_H
+#ifndef _E820_H
+#define _E820_H
 
 /*
  * Copyright (C) 2021 Michael Brown <mbrown@fensystems.co.uk>.
@@ -56,4 +56,4 @@ struct e820_entry
 
 extern struct e820_entry *memmap_next (struct e820_entry *prev);
 
-#endif /* _MEMMAP_H */
+#endif /* _E820_H */
diff --git a/kern/build.mk b/kern/build.mk
new file mode 100644
index 0000000..8b93c4a
--- /dev/null
+++ b/kern/build.mk
@@ -0,0 +1,26 @@
+# Objects
+OBJ_KERN := kern/callback.o
+OBJ_KERN += kern/cmdline.o
+OBJ_KERN += kern/cookie.o
+OBJ_KERN += kern/die.o
+OBJ_KERN += kern/e820.o
+OBJ_KERN += kern/efi.o
+OBJ_KERN += kern/efiblock.o
+OBJ_KERN += kern/efiboot.o
+OBJ_KERN += kern/efifile.o
+OBJ_KERN += kern/efimain.o
+OBJ_KERN += kern/int13.o
+OBJ_KERN += kern/main.o
+OBJ_KERN += kern/paging.o
+OBJ_KERN += kern/payload.o
+OBJ_KERN += kern/startup.o
+
+OBJECTS += $(OBJ_KERN)
+
+OBJECTS_i386 += $(patsubst %.o,%.i386.o,$(OBJ_KERN))
+OBJECTS_x86_64 += $(patsubst %.o,%.x86_64.o,$(OBJ_KERN))
+OBJECTS_i386_x86_64 += $(patsubst %.o,%.i386.x86_64.o,$(OBJ_KERN))
+OBJECTS_arm64 += $(patsubst %.o,%.arm64.o,$(OBJ_KERN))
+
+RM_FILES += kern/*.s kern/*.o
+
diff --git a/callback.S b/kern/callback.S
similarity index 100%
rename from callback.S
rename to kern/callback.S
diff --git a/cmdline.c b/kern/cmdline.c
similarity index 100%
rename from cmdline.c
rename to kern/cmdline.c
diff --git a/cookie.c b/kern/cookie.c
similarity index 100%
rename from cookie.c
rename to kern/cookie.c
diff --git a/die.c b/kern/die.c
similarity index 100%
rename from die.c
rename to kern/die.c
diff --git a/memmap.c b/kern/e820.c
similarity index 99%
rename from memmap.c
rename to kern/e820.c
index d82c589..5a78599 100644
--- a/memmap.c
+++ b/kern/e820.c
@@ -28,7 +28,7 @@
 #include <stdio.h>
 #include <string.h>
 #include "ntloader.h"
-#include "memmap.h"
+#include "e820.h"
 
 /** Buffer for INT 15,e820 calls */
 static struct e820_entry e820_buf __attribute__ ((section (".bss16")));
diff --git a/efi.c b/kern/efi.c
similarity index 100%
rename from efi.c
rename to kern/efi.c
diff --git a/efiblock.c b/kern/efiblock.c
similarity index 100%
rename from efiblock.c
rename to kern/efiblock.c
diff --git a/efiboot.c b/kern/efiboot.c
similarity index 100%
rename from efiboot.c
rename to kern/efiboot.c
diff --git a/efifile.c b/kern/efifile.c
similarity index 100%
rename from efifile.c
rename to kern/efifile.c
diff --git a/efimain.c b/kern/efimain.c
similarity index 100%
rename from efimain.c
rename to kern/efimain.c
diff --git a/int13.c b/kern/int13.c
similarity index 100%
rename from int13.c
rename to kern/int13.c
diff --git a/main.c b/kern/main.c
similarity index 99%
rename from main.c
rename to kern/main.c
index aaa3538..9db3e40 100644
--- a/main.c
+++ b/kern/main.c
@@ -29,7 +29,7 @@
 #include "payload.h"
 #include "cmdline.h"
 #include "paging.h"
-#include "memmap.h"
+#include "e820.h"
 #include "biosdisk.h"
 
 /** Start of our image (defined by linker) */
diff --git a/paging.c b/kern/paging.c
similarity index 99%
rename from paging.c
rename to kern/paging.c
index 199c2a2..0bbaadf 100644
--- a/paging.c
+++ b/kern/paging.c
@@ -29,7 +29,7 @@
 #include <string.h>
 #include <assert.h>
 #include "ntloader.h"
-#include "memmap.h"
+#include "e820.h"
 #include "paging.h"
 
 #if defined(__i386__) || defined(__x86_64__)
diff --git a/payload.c b/kern/payload.c
similarity index 100%
rename from payload.c
rename to kern/payload.c
diff --git a/startup.S b/kern/startup.S
similarity index 100%
rename from startup.S
rename to kern/startup.S
diff --git a/bcd.c b/libnt/bcd.c
similarity index 100%
rename from bcd.c
rename to libnt/bcd.c
diff --git a/libnt/build.mk b/libnt/build.mk
new file mode 100644
index 0000000..f7373f0
--- /dev/null
+++ b/libnt/build.mk
@@ -0,0 +1,17 @@
+# Objects
+OBJ_LIBNT := libnt/bcd.o
+OBJ_LIBNT += libnt/charset.o
+OBJ_LIBNT += libnt/cpio.o
+OBJ_LIBNT += libnt/peloader.o
+OBJ_LIBNT += libnt/reg.o
+OBJ_LIBNT += libnt/vdisk.o
+
+OBJECTS += $(OBJ_LIBNT)
+
+OBJECTS_i386 += $(patsubst %.o,%.i386.o,$(OBJ_LIBNT))
+OBJECTS_x86_64 += $(patsubst %.o,%.x86_64.o,$(OBJ_LIBNT))
+OBJECTS_i386_x86_64 += $(patsubst %.o,%.i386.x86_64.o,$(OBJ_LIBNT))
+OBJECTS_arm64 += $(patsubst %.o,%.arm64.o,$(OBJ_LIBNT))
+
+RM_FILES += libnt/*.s libnt/*.o
+
diff --git a/charset.c b/libnt/charset.c
similarity index 100%
rename from charset.c
rename to libnt/charset.c
diff --git a/cpio.c b/libnt/cpio.c
similarity index 100%
rename from cpio.c
rename to libnt/cpio.c
diff --git a/peloader.c b/libnt/peloader.c
similarity index 100%
rename from peloader.c
rename to libnt/peloader.c
diff --git a/reg.c b/libnt/reg.c
similarity index 100%
rename from reg.c
rename to libnt/reg.c
diff --git a/vdisk.c b/libnt/vdisk.c
similarity index 100%
rename from vdisk.c
rename to libnt/vdisk.c
diff --git a/posix/build.mk b/posix/build.mk
new file mode 100644
index 0000000..610a4b8
--- /dev/null
+++ b/posix/build.mk
@@ -0,0 +1,13 @@
+# Objects
+OBJ_POSIX := posix/stdio.o
+OBJ_POSIX += posix/string.o
+OBJ_POSIX += posix/vsprintf.o
+
+OBJECTS += $(OBJ_POSIX)
+
+OBJECTS_i386 += $(patsubst %.o,%.i386.o,$(OBJ_POSIX))
+OBJECTS_x86_64 += $(patsubst %.o,%.x86_64.o,$(OBJ_POSIX))
+OBJECTS_i386_x86_64 += $(patsubst %.o,%.i386.x86_64.o,$(OBJ_POSIX))
+OBJECTS_arm64 += $(patsubst %.o,%.arm64.o,$(OBJ_POSIX))
+
+RM_FILES += posix/*.s posix/*.o
diff --git a/stdio.c b/posix/stdio.c
similarity index 100%
rename from stdio.c
rename to posix/stdio.c
diff --git a/string.c b/posix/string.c
similarity index 100%
rename from string.c
rename to posix/string.c
diff --git a/vsprintf.c b/posix/vsprintf.c
similarity index 100%
rename from vsprintf.c
rename to posix/vsprintf.c