Merge with git+ssh://master.kernel.org/pub/scm/boot/syslinux/syslinux.git#syslinux-3.3xsyslinux-3.40-pre5

40 files changed, 865 insertions, 290 deletions

diff --git a/Makefile b/Makefile
index 7673cf5c..5a27526c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 ## -----------------------------------------------------------------------
 ##
-##   Copyright 1998-2006 H. Peter Anvin - All Rights Reserved
+##   Copyright 1998-2007 H. Peter Anvin - All Rights Reserved
 ##
 ##   This program is free software; you can redistribute it and/or modify
 ##   it under the terms of the GNU General Public License as published by
@@ -17,12 +17,18 @@
 # No builtin rules
 MAKEFLAGS = -r
 
+gcc_ok   = $(shell if gcc $(1) dummy.c -o /dev/null 2>/dev/null; \
+	           then echo '$(1)'; else echo '$(2)'; fi)
+
+comma   := ,
+LDHASH  := $(call gcc_ok,-Wl$(comma)--hash-style=both,)
+
 OSTYPE   = $(shell uname -msr)
 CC	 = gcc
 INCLUDE  =
 CFLAGS   = -W -Wall -Os -fomit-frame-pointer -D_FILE_OFFSET_BITS=64
 PIC      = -fPIC
-LDFLAGS  = -O2 -s
+LDFLAGS  = -O2 -s $(LDHASH)
 AR	 = ar
 RANLIB   = ranlib
 
@@ -63,12 +69,16 @@ BINFILES = bootsect_bin.c ldlinux_bin.c mbr_bin.c \
 # mingw suite installed
 BTARGET  = kwdhash.gen version.gen version.h \
 	   ldlinux.bss ldlinux.sys ldlinux.bin \
-	   pxelinux.0 mbr.bin isolinux.bin isolinux-debug.bin \
+	   pxelinux.0 isolinux.bin isolinux-debug.bin \
 	   extlinux.bin extlinux.bss extlinux.sys
-BOBJECTS = $(BTARGET) dos/syslinux.com win32/syslinux.exe memdisk/memdisk
+BOBJECTS = $(BTARGET) mbr/mbr.bin dos/syslinux.com win32/syslinux.exe memdisk/memdisk
+# BESUBDIRS and IESUBDIRS are "early", i.e. before the root; BSUBDIRS
+# and ISUBDIRS are "late", after the root.
+BESUBDIRS = mbr
 BSUBDIRS = memdisk dos win32
 ITARGET  = copybs.com gethostip mkdiskimage
 IOBJECTS = $(ITARGET) mtools/syslinux unix/syslinux extlinux/extlinux
+IESUBDIRS =
 ISUBDIRS = mtools unix extlinux sample com32
 DOCS     = COPYING NEWS README TODO BUGS *.doc sample menu com32
 OTHER    = Makefile bin2c.pl now.pl genhash.pl keywords findpatch.pl \
@@ -82,7 +92,7 @@ INSTALL_BIN   =	mtools/syslinux gethostip ppmtolss16 lss16toppm
 INSTALL_SBIN  = extlinux/extlinux
 # Things to install in /usr/lib/syslinux
 INSTALL_AUX   =	pxelinux.0 isolinux.bin isolinux-debug.bin \
-		dos/syslinux.com copybs.com memdisk/memdisk mbr.bin
+		dos/syslinux.com copybs.com memdisk/memdisk mbr/mbr.bin
 INSTALL_AUX_OPT = win32/syslinux.exe
 
 # The DATE is set on the make command line when building binaries for
@@ -102,9 +112,10 @@ MAKE    += DATE=$(DATE) HEXDATE=$(HEXDATE)
 # error every time you try to build.
 #
 
-all:	all-local
-	set -e ; for i in $(BSUBDIRS) $(ISUBDIRS) ; do $(MAKE) -C $$i $@ ; done
+all:
+	set -e ; for i in $(BESUBDIRS) $(IESUBDIRS) ; do $(MAKE) -C $$i $@ ; done
 	$(MAKE) all-local
+	set -e ; for i in $(BSUBDIRS) $(ISUBDIRS) ; do $(MAKE) -C $$i $@ ; done
 	-ls -l $(BOBJECTS) $(IOBJECTS)
 
 all-local: $(BTARGET) $(ITARGET) $(BINFILES)
@@ -167,10 +178,7 @@ extlinux.bss: extlinux.bin
 extlinux.sys: extlinux.bin
 	dd if=$< of=$@ bs=512 skip=1
 
-mbr.bin: mbr.asm
-	$(NASM) -f bin -l mbr.lst -o mbr.bin mbr.asm
-
-mbr_bin.c: mbr.bin bin2c.pl
+mbr_bin.c: mbr/mbr.bin bin2c.pl
 	$(PERL) bin2c.pl syslinux_mbr < $< > $@
 
 copybs.com: copybs.asm
@@ -199,8 +207,8 @@ $(LIB_SO): bootsect_bin.o ldlinux_bin.o syslxmod.o
 gethostip: gethostip.o
 	$(CC) $(LDFLAGS) -o $@ $^
 
-mkdiskimage: mkdiskimage.in mbr.bin bin2hex.pl
-	$(PERL) bin2hex.pl < mbr.bin | cat mkdiskimage.in - > $@
+mkdiskimage: mkdiskimage.in mbr/mbr.bin bin2hex.pl
+	$(PERL) bin2hex.pl < mbr/mbr.bin | cat mkdiskimage.in - > $@
 	chmod a+x $@
 
 install: installer
diff --git a/Makefile.private b/Makefile.private
index 63a3bbdf..8573aa44 100644
--- a/Makefile.private
+++ b/Makefile.private
@@ -35,8 +35,8 @@ burn: isolinux.iso
 	cdrecord -v blank=fast isolinux.iso
 
 official:
-	$(MAKE) spotless CC='$(CC) -m32' 
-	$(MAKE) depend CC='$(CC) -m32' 
+	$(MAKE) spotless CC='$(CC) -m32'
+	$(MAKE) depend CC='$(CC) -m32'
 	$(MAKE) all CC='$(CC) -m32'
 	$(MAKE) dist CC='$(CC) -m32'
 
diff --git a/NEWS b/NEWS
index 646b5c2f..2b450a0f 100644
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,17 @@ Changes in 3.40:
 	* It is now supported to load a different configuration file
 	  with the CONFIG keyword.
 
+Changes in 3.36:
+	* MEMDISK: Disable EDD by default on floppy disks.  EDD can be
+	  enabled with the "edd" option and disabled with "noedd".
+	  This (hopefully) should make Ghost work again.
+	* SYSLINUX: "unix" installer now uses Linux ioctls instead of
+	  using libfat.
+	* New MBR which can boot from logical partitions.
+	* SYSLINUX: Fix bug in detecting special extensions which was
+	  introduced in 3.35 :(
+	* PXELINUX: Unbreak chainbooting FreeBSD (and possibly others.)
+
 Changes in 3.35:
 	* MEMDISK: New "safeint" mode.
 	* MEMDISK: Be more compliant with the PnP BIOS spec.
diff --git a/README.menu b/README.menu
index 6f0fd83c..fe4f9091 100644
--- a/README.menu
+++ b/README.menu
@@ -186,13 +186,13 @@ MENU COLOR element ansi foreground background shadow
 	represents fully transparent, and #ffffffff represents opaque
 	white.
 
-	
+
 	"shadow" controls the handling of the graphical console text
 	shadow.  Permitted values are "none" (no shadowing), "std" or
 	"standard" (standard shadowing - foreground pixels are
 	raised), "all" (both background and foreground raised), and
 	"rev" or "reverse" (background pixels are raised.)
-	
+
 
 	If any field is set to "*" or omitted (at the end of the line)
 	then that field is left unchanged.
diff --git a/TODO b/TODO
index e2aacca6..93f3194d 100644
--- a/TODO
+++ b/TODO
@@ -31,4 +31,3 @@
 - COM32-based CLI.
 
 - Rewrite the filesystems to run in protected mode C code.
-
diff --git a/abort.inc b/abort.inc
index e6bf0d52..fd136529 100644
--- a/abort.inc
+++ b/abort.inc
@@ -62,4 +62,4 @@ error_or_command:
 		mov cx,[OnerrorLen]
 		and cx,cx
 		jnz on_error
-		jmp enter_command
\ No newline at end of file
+		jmp enter_command
diff --git a/bootsect.inc b/bootsect.inc
index 16c5f5e9..7c288daf 100644
--- a/bootsect.inc
+++ b/bootsect.inc
@@ -136,6 +136,11 @@ replace_bootstrap:
 		mov [es:di+12],esi	; New ESI
 		mov [es:di+6],bx	; New DS
 
+%if IS_PXELINUX == 0
+		; DON'T DO THIS FOR PXELINUX...
+		; For PXE, ES:BX -> PXENV+, and this would corrupt
+		; that use.
+
 		; Hunt for $PnP header if one exists
 		mov ax,0F000h
 		mov fs,ax
@@ -163,6 +168,7 @@ replace_bootstrap:
 		; Found a valid $PnP header, point ES:DI to it
 		mov [es:di+8], bx	; New DI
 		mov [es:di+4], fs	; New ES
+%endif
 
 .donepnp:
 		pop ax			; Copy list count
diff --git a/cache.inc b/cache.inc
index e2595a21..47d815f6 100644
--- a/cache.inc
+++ b/cache.inc
@@ -1,6 +1,6 @@
 ; -*- fundamental -*- ---------------------------------------------------
 ;
-;   Copyright 2004 H. Peter Anvin - All Rights Reserved
+;   Copyright 2004-2007 H. Peter Anvin - All Rights Reserved
 ;
 ;   This program is free software; you can redistribute it and/or modify
 ;   it under the terms of the GNU General Public License as published by
@@ -11,17 +11,33 @@
 ; -----------------------------------------------------------------------
 
 		section .text
+
+		struc cptr
+.sector:	resd 1				; Sector number
+.prev:		resw 1				; LRU pointer to previous (less recent)
+.next:		resw 1				; LRU pointer to next (more recent)
+		endstruc
+cptr_size_lg2	equ 3
+
+NCacheEntries	equ 65536/SECTOR_SIZE
+
 ;
 ; initcache: Initialize the cache data structures
 ;
 initcache:
 		xor eax,eax			; We don't care about sector 0
 		mov di,CachePtrs
-		mov cx,65536/SECTOR_SIZE
-		rep stosd
+		mov cx,NCacheEntries+1
+		mov bx,CachePtrs+NCacheEntries*cptr_size	; "prev" pointer
+.loop:
+		mov [di+cptr.sector],eax	; Zero sector number
+		mov [di+cptr.prev],bx		; Previous pointer
+		mov [bx+cptr.next],di		; Previous entry's next pointer
+		mov bx,di
+		add di,cptr_size
+		loop .loop
 		ret
 
-
 ;
 ; getcachesector: Check for a particular sector (EAX) in the sector cache,
 ;		  and if it is already there, return a pointer in GS:SI
@@ -31,32 +47,29 @@ initcache:
 ;
 getcachesector:
 		push cx
+		push bx
+		push di
 		mov si,cache_seg
 		mov gs,si
-		mov si,CachePtrs	; Sector cache pointers
-		mov cx,65536/SECTOR_SIZE
+		mov si,CachePtrs+cptr_size	; Real sector cache pointers
+		mov cx,NCacheEntries
 .search:
 		cmp eax,[si]
 		jz .hit
-		add si,4
+		add si,cptr_size
 		loop .search
 
 .miss:
 		TRACER 'M'
-		; Need to load it.  Highly inefficient cache replacement
-		; algorithm: Least Recently Written (LRW)
-		push bx
+		; Need to load it.
 		push es
 		push gs
 		pop es
-		mov bx,[NextCacheSlot]
-		inc bx
-		and bx,(1 << (16-SECTOR_SHIFT))-1
-		mov [NextCacheSlot],bx
-		shl bx,2
-		mov [CachePtrs+bx],eax
-		shl bx,SECTOR_SHIFT-2
+		mov bx,[CachePtrs+cptr.next]	; "Next most recent than head node"
+		mov [bx+cptr.sector],eax
 		mov si,bx
+		sub bx,CachePtrs+cptr_size
+		shl bx,SECTOR_SHIFT-cptr_size_lg2	; Buffer address
 		pushad
 %if IS_EXTLINUX
 		call getonesec_ext
@@ -65,18 +78,38 @@ getcachesector:
 %endif
 		popad
 		pop es
-		pop bx
-		pop cx
-		ret
-
-.hit:		; We have it; get the pointer
+.hit:
+		; Update LRU, then compute buffer address
 		TRACER 'H'
-		sub si,CachePtrs
-		shl si,SECTOR_SHIFT-2
+
+		; Remove from current position in the list
+		mov bx,[si+cptr.prev]
+		mov di,[si+cptr.next]
+		mov [bx+cptr.next],di
+		mov [di+cptr.prev],bx
+
+		; Add to just before head node
+		mov bx,[CachePtrs+cptr.prev]
+		mov [si+cptr.prev],bx
+		mov [bx+cptr.next],si
+		mov [CachePtrs+cptr.prev],si
+		mov word [si+cptr.next],CachePtrs
+
+		sub si,CachePtrs+cptr_size
+		shl si,SECTOR_SHIFT-cptr_size_lg2	; Buffer address
+
+		pop di
+		pop bx
 		pop cx
 		ret
 
 		section .latebss
+
+		; Each CachePtr contains:
+		; - Block pointer
+		; - LRU previous pointer
+		; - LRU next pointer
+		; The first entry is the head node of the list
 		alignb 4
-CachePtrs	resd 65536/SECTOR_SIZE	; Cached sector pointers
-NextCacheSlot	resw 1			; Next cache slot to occupy
+CachePtrs	resb (NCacheEntries+1)*cptr_size
+
diff --git a/com32/lib/MCONFIG b/com32/lib/MCONFIG
index 39b62db1..461ada44 100644
--- a/com32/lib/MCONFIG
+++ b/com32/lib/MCONFIG
@@ -1,5 +1,10 @@
 # -*- makefile -*-
 
+gcc_ok  = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
+	  then echo $(1); else echo $(2); fi)
+
+GCCOPT := $(call gcc_ok,-m32,) $(call gcc_ok,-fno-stack-protector,)
+
 CC	= gcc
 LD	= ld
 INCLUDE	= -I.
@@ -21,7 +26,7 @@ LIBFLAGS = -DDYNAMIC_CRC_TABLE -DPNG_NO_CONSOLE_IO \
 # fallback anyway, just use that on old machines...
 # LIBFLAGS += -DPNG_NO_FLOATING_POINT_SUPPORTED
 
-REQFLAGS  = -g -m32 -mregparm=3 -DREGPARM=3 -D__COM32__ -I. -I./sys -I../include
+REQFLAGS  = $(GCCOPT) -g -mregparm=3 -DREGPARM=3 -D__COM32__ -I. -I./sys -I../include
 OPTFLAGS  = -Os -march=i386 -falign-functions=0 -falign-jumps=0 \
 	    -falign-labels=0 -ffast-math -fomit-frame-pointer
 WARNFLAGS = -W -Wall -Wpointer-arith -Wwrite-strings -Wstrict-prototypes -Winline
diff --git a/com32/lib/sys/fileread.c b/com32/lib/sys/fileread.c
index e184fc35..8fdd9167 100644
--- a/com32/lib/sys/fileread.c
+++ b/com32/lib/sys/fileread.c
@@ -46,7 +46,7 @@ ssize_t __file_read(struct file_info *fp, void *buf, size_t count)
 
   memset(&ireg, 0, sizeof ireg);
   ireg.eax.w[0] = 0x0007;	/* Read file */
-  ireg.esi.w[0] = OFFS(__com32.cs_bounce);
+  ireg.ebx.w[0] = OFFS(__com32.cs_bounce);
   ireg.es = SEG(__com32.cs_bounce);
 
   while ( count ) {
@@ -64,7 +64,7 @@ ssize_t __file_read(struct file_info *fp, void *buf, size_t count)
 	return -1;
       }
 
-      fp->i.filedes = ireg.esi.w[0];
+      fp->i.filedes = oreg.esi.w[0];
       fp->i.nbytes = min(fp->i.length-fp->i.offset, (unsigned)MAXBLOCK);
       fp->i.datap = fp->i.buf;
       memcpy(fp->i.buf, __com32.cs_bounce, fp->i.nbytes);
diff --git a/com32/libutil/Makefile b/com32/libutil/Makefile
index 9adeec66..3656fb3f 100644
--- a/com32/libutil/Makefile
+++ b/com32/libutil/Makefile
@@ -32,7 +32,7 @@
 gcc_ok   = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
 	           then echo $(1); else echo $(2); fi)
 
-M32     := $(call gcc_ok,-m32,)
+M32     := $(call gcc_ok,-m32,) $(call gcc_ok,-fno-stack-protector,)
 
 CC         = gcc
 LD         = ld -m elf_i386
diff --git a/com32/modules/Makefile b/com32/modules/Makefile
index 3c272f26..877ce399 100644
--- a/com32/modules/Makefile
+++ b/com32/modules/Makefile
@@ -17,7 +17,7 @@
 gcc_ok   = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
 	           then echo $(1); else echo $(2); fi)
 
-M32     := $(call gcc_ok,-m32,)
+M32     := $(call gcc_ok,-m32,) $(call gcc_ok,-fno-stack-protector,)
 
 CC         = gcc
 LD         = ld -m elf_i386
diff --git a/com32/samples/Makefile b/com32/samples/Makefile
index 213ae1a3..291413a6 100644
--- a/com32/samples/Makefile
+++ b/com32/samples/Makefile
@@ -17,7 +17,7 @@
 gcc_ok   = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
 	           then echo $(1); else echo $(2); fi)
 
-M32     := $(call gcc_ok,-m32,)
+M32     := $(call gcc_ok,-m32,) $(call gcc_ok,-fno-stack-protector,)
 
 CC         = gcc
 LD         = ld -m elf_i386
diff --git a/comboot.doc b/comboot.doc
index 00743835..0d7af174 100644
--- a/comboot.doc
+++ b/comboot.doc
@@ -699,7 +699,7 @@ AX=0017h [3.30] Report video mode change
 	which are undefined in the current version of SYSLINUX.
 
 	The following bits in BX are currently defined:
-	
+
 	Bit 0: graphics mode
 
 		Indicates that the mode is a graphics mode, as opposed
diff --git a/comboot.inc b/comboot.inc
index fac5753e..304accaa 100644
--- a/comboot.inc
+++ b/comboot.inc
@@ -776,7 +776,7 @@ comapi_userfont:
 .done:		; CF=0 here
 		mov P_AL,al
 		ret
-		
+
 ;
 ; INT 22h AX=0019h  Read disk
 ;
diff --git a/dos/Makefile b/dos/Makefile
index 61423cec..5fd52d1b 100644
--- a/dos/Makefile
+++ b/dos/Makefile
@@ -1,9 +1,14 @@
+gcc_ok   = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
+	           then echo $(1); else echo $(2); fi)
+
+M32       := $(call gcc_ok,-m32,) $(call gcc_ok,-ffreestanding,) $(call gcc_ok,-fno-stack-protector,)
+
 CC	 = gcc
 LD       = ld -m elf_i386
 OBJCOPY  = objcopy
 OPTFLAGS = -g -Os -march=i386 -falign-functions=0 -falign-jumps=0 -falign-loops=0 -fomit-frame-pointer
 INCLUDES = -include code16.h -I. -I.. -I../libfat
-CFLAGS	 = -m32 -mregparm=3 -DREGPARM=3 -W -Wall -ffreestanding -msoft-float $(OPTFLAGS) $(INCLUDES)
+CFLAGS	 = $(M32) -mregparm=3 -DREGPARM=3 -W -Wall -msoft-float $(OPTFLAGS) $(INCLUDES)
 LDFLAGS	 = -T com16.ld
 AR       = ar
 RANLIB   = ranlib
diff --git a/dummy.c b/dummy.c
new file mode 100644
index 00000000..81f2586c
--- /dev/null
+++ b/dummy.c
@@ -0,0 +1,8 @@
+/*
+ * Trivial C program to test the compiler
+ */
+
+int main(int argc, char *argv[])
+{
+  return 0;
+}
diff --git a/extlinux.asm b/extlinux.asm
index ddc0cc6b..e4628478 100644
--- a/extlinux.asm
+++ b/extlinux.asm
@@ -5,7 +5,7 @@
 ;
 ;  A program to boot Linux kernels off an ext2/ext3 filesystem.
 ;
-;   Copyright (C) 1994-2006  H. Peter Anvin
+;   Copyright (C) 1994-2007  H. Peter Anvin
 ;
 ;  This program is free software; you can redistribute it and/or modify
 ;  it under the terms of the GNU General Public License as published by
@@ -112,7 +112,7 @@ trackbuf	resb trackbufsize	; Track buffer goes here
 getcbuf		resb trackbufsize
 		; ends at 4800h
 
-		section .latebss
+		section .bss
 SuperBlock	resb 1024		; ext2 superblock
 SuperInfo	resq 16			; DOS superblock expanded
 ClustSize	resd 1			; Bytes/cluster ("block")
@@ -1024,7 +1024,7 @@ open_inode:
 		pop di
 		ret
 
-		section .latebss
+		section .bss
 		alignb 4
 ThisInode	resb EXT2_GOOD_OLD_INODE_SIZE	; The most recently opened inode
 
diff --git a/extlinux/Makefile b/extlinux/Makefile
index a450a3dc..8d347a98 100644
--- a/extlinux/Makefile
+++ b/extlinux/Makefile
@@ -1,8 +1,14 @@
+gcc_ok   = $(shell if gcc $(1) ../dummy.c -o /dev/null 2>/dev/null; \
+	           then echo '$(1)'; else echo '$(2)'; fi)
+
+comma   := ,
+LDHASH  := $(call gcc_ok,-Wl$(comma)--hash-style=both,)
+
 CC	 = gcc
 OPTFLAGS = -g -Os
 INCLUDES = -I. -I.. -I../libfat
 CFLAGS	 = -W -Wall -Wno-sign-compare -D_FILE_OFFSET_BITS=64 $(OPTFLAGS) $(INCLUDES)
-LDFLAGS	 = -s
+LDFLAGS	 = $(LDHASH) -s
 
 SRCS     = extlinux.c ../extlinux_bss_bin.c ../extlinux_sys_bin.c
 OBJS	 = $(patsubst %.c,%.o,$(notdir $(SRCS)))
diff --git a/font.inc b/font.inc
index c2d1350e..4eeee1d5 100644
--- a/font.inc
+++ b/font.inc
@@ -75,7 +75,7 @@ use_font:
 
 		test byte [UsingVGA], 01h	; Are we in graphics mode?
 		jz .text
-		
+
 .graphics:
 		xor cx,cx
 		mov cl,bh			; CX = bytes/character
diff --git a/head.inc b/head.inc
index e0682b2f..17562079 100644
--- a/head.inc
+++ b/head.inc
@@ -1,6 +1,6 @@
 ; -*- fundamental -*- (asm-mode sucks)
 ; -----------------------------------------------------------------------
-;   
+;
 ;   Copyright 2006 H. Peter Anvin - All Rights Reserved
 ;
 ;   This program is free software; you can redistribute it and/or modify
diff --git a/layout.inc b/layout.inc
index d3b9f05b..7b122d74 100644
--- a/layout.inc
+++ b/layout.inc
@@ -1,6 +1,6 @@
 ; -----------------------------------------------------------------------
 ;
-;   Copyright 1994-2004 H. Peter Anvin - All Rights Reserved
+;   Copyright 1994-2007 H. Peter Anvin - All Rights Reserved
 ;
 ;   This program is free software; you can redistribute it and/or modify
 ;   it under the terms of the GNU General Public License as published by
@@ -26,7 +26,7 @@ TEXT_START	equ 7C00h
 ; The secondary BSS section, above the text; we really wish we could
 ; just make it follow .bcopy32 or hang off the end,
 ; but it doesn't seem to work that way.
-LATEBSS_START	equ 0B400h
+LATEBSS_START	equ 0B200h
 
 ; Reserve memory for the stack.  This causes checkov to abort the
 ; compile if we violate this space.
diff --git a/ldlinux.asm b/ldlinux.asm
index d1c0c65a..69259247 100644
--- a/ldlinux.asm
+++ b/ldlinux.asm
@@ -123,7 +123,6 @@ RootDir		resd 1			; Location of root directory proper
 DataArea	resd 1			; Location of data area
 RootDirSize	resd 1			; Root dir size in sectors
 TotalSectors	resd 1			; Total number of sectors
-EndSector	resd 1			; Location of filesystem end
 ClustSize	resd 1			; Bytes/cluster
 ClustMask	resd 1			; Sectors/cluster - 1
 CopySuper	resb 1			; Distinguish .bs versus .bss
@@ -795,9 +794,6 @@ genfatinfo:
 .have_secs:
 		mov [TotalSectors],edx
 
-		add edx,eax
-		mov [EndSector],edx
-
 		mov eax,[bxResSectors]
 		mov [FAT],eax			; Beginning of FAT
 		mov edx,[bxFATsecs]
@@ -835,7 +831,7 @@ genfatinfo:
 ; FAT12, FAT16 or FAT28^H^H32?  This computation is fscking ridiculous.
 ;
 getfattype:
-		mov eax,[EndSector]
+		mov eax,[TotalSectors]
 		sub eax,[DataArea]
 		shr eax,cl			; cl == ClustShift
 		mov cl,nextcluster_fat12-(nextcluster+2)
@@ -1605,11 +1601,11 @@ initrd_cmd_len	equ 7
 ;
 ; Extensions to search for (in *forward* order).
 ;
-exten_table:	db 'CBT',0		; COMBOOT (specific)
-		db 'BSS',0		; Boot Sector (add superblock)
-		db 'BS ',0		; Boot Sector
-		db 'COM',0		; COMBOOT (same as DOS)
-		db 'C32',0		; COM32
+exten_table:	db '.cbt'		; COMBOOT (specific)
+		db '.bss'		; Boot Sector (add superblock)
+		db '.bs', 0		; Boot Sector
+		db '.com'		; COMBOOT (same as DOS)
+		db '.c32'		; COM32
 exten_table_end:
 		dd 0, 0			; Need 8 null bytes here
 
diff --git a/loadhigh.inc b/loadhigh.inc
index 7d9f57a4..283778f6 100644
--- a/loadhigh.inc
+++ b/loadhigh.inc
@@ -88,7 +88,7 @@ load_high:
 		sub eax,ecx
 		pop bx				; <AA> Pausebird function
 		jnz .read_loop			; More to read...
-		
+
 
 .eof:
 		pop es				; <AAA> ES
diff --git a/mbr/Makefile b/mbr/Makefile
new file mode 100644
index 00000000..d61f7f1c
--- /dev/null
+++ b/mbr/Makefile
@@ -0,0 +1,47 @@
+## -----------------------------------------------------------------------
+##   
+##   Copyright 2007 H. Peter Anvin - All Rights Reserved
+##
+##   This program is free software; you can redistribute it and/or modify
+##   it under the terms of the GNU General Public License as published by
+##   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
+##   Boston MA 02111-1307, USA; either version 2 of the License, or
+##   (at your option) any later version; incorporated herein by reference.
+##
+## -----------------------------------------------------------------------
+
+#
+# Makefile for MBR
+#
+
+gcc_ok   = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
+	           then echo $(1); else echo $(2); fi)
+
+M32       := $(call gcc_ok,-m32,) $(call gcc_ok,-ffreestanding,) $(call gcc_ok,-fno-stack-protector)
+
+CC         = gcc
+LD         = ld -m elf_i386
+SFLAGS	   = $(M32) -march=i386
+OBJCOPY	   = objcopy
+PERL	   = perl
+
+.SUFFIXES: .S .s .o .elf
+
+all:	mbr.bin
+
+.PRECIOUS: %.o
+%.o: %.S
+	$(CC) $(SFLAGS) -Wa,-a=$*.lst -c -o $@ $<
+
+mbr.elf: mbr.o mbr.ld
+	$(LD) -T mbr.ld -e _start -o $@ $<
+
+mbr.bin: mbr.elf checksize.pl
+	$(OBJCOPY) -O binary $< $@
+	$(PERL) checksize.pl mbr.bin 440
+
+tidy:
+	rm -f *.o *.elf *.lst
+
+clean: tidy
+	rm -f *.bin
diff --git a/mbr/checksize.pl b/mbr/checksize.pl
new file mode 100755
index 00000000..b7d560a0
--- /dev/null
+++ b/mbr/checksize.pl
@@ -0,0 +1,31 @@
+## -----------------------------------------------------------------------
+##   
+##   Copyright 2007 H. Peter Anvin - All Rights Reserved
+##
+##   This program is free software; you can redistribute it and/or modify
+##   it under the terms of the GNU General Public License as published by
+##   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
+##   Boston MA 02111-1307, USA; either version 2 of the License, or
+##   (at your option) any later version; incorporated herein by reference.
+##
+## -----------------------------------------------------------------------
+
+##
+## checksize.pl
+##
+## Check the size of a binary file
+##
+
+($file, $maxsize) = @ARGV;
+
+@st = stat($file);
+if (!defined($size = $st[7])) {
+    die "$0: $file: $!\n";
+}
+if ($size > $maxsize) {
+    print STDERR "$file: too big ($size > $maxsize)\n";
+    exit 1;
+} else {
+    exit 0;
+}
+
diff --git a/mbr/mbr.S b/mbr/mbr.S
new file mode 100644
index 00000000..81e5dd00
--- /dev/null
+++ b/mbr/mbr.S
@@ -0,0 +1,299 @@
+/* -----------------------------------------------------------------------
+ *   
+ *   Copyright 2007 H. Peter Anvin - All Rights Reserved
+ *
+ *   Permission is hereby granted, free of charge, to any person
+ *   obtaining a copy of this software and associated documentation
+ *   files (the "Software"), to deal in the Software without
+ *   restriction, including without limitation the rights to use,
+ *   copy, modify, merge, publish, distribute, sublicense, and/or
+ *   sell copies of the Software, and to permit persons to whom
+ *   the Software is furnished to do so, subject to the following
+ *   conditions:
+ *   
+ *   The above copyright notice and this permission notice shall
+ *   be included in all copies or substantial portions of the Software.
+ *   
+ *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *   OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * ----------------------------------------------------------------------- */
+
+	.code16
+	.text
+
+	.globl	bootsec
+stack   = 0x7c00
+driveno	= (stack-6)
+heads	= (stack-8)
+sectors	= (stack-10)
+
+BIOS_page = 0x462
+
+	/* gas/ld has issues with doing this as absolute addresses... */
+	.section ".bootsec", "a", @nobits
+	.globl	bootsec
+bootsec:
+	.space	512
+
+	.text	
+	.globl	_start
+_start:
+	cli
+	xorw	%ax, %ax
+	movw	%ax, %ds
+	movw	%ax, %ss
+	movw	$stack, %sp
+	movw	%sp, %si
+	pushw	%es		/* es:di -> $PnP header */
+	pushw	%di
+	pushw	%dx		/* dl -> drive number */
+	movw	%ax, %es
+	sti
+	cld
+
+	/* Copy down to 0:0x600 */
+	movw	$_start, %di
+	movw	$(512/2), %cx
+	rep; movsw
+
+	ljmpw	$0, $next
+
+next:
+	/* Check to see if we have EBIOS */
+	pushw	%dx		/* drive number */
+	movw	$0x4100, %ax
+	movw	$0x55aa, %bx
+	xorw	%cx, %cx
+	xorb	%dh, %dh
+	stc
+	int	$0x13
+	jc	1f
+	cmpw	$0xaa55, %bx
+	jne	1f
+	testb	$0x01, %cl
+	jz	1f
+
+	/* We have EBIOS; patch in a jump to read_sector_ebios */
+	movw	$0xeb+((read_sector_ebios-read_sector_cbios-2)<< 8), (read_sector_cbios)
+
+1:
+	popw	%dx
+
+	/* Get (C)HS geometry */
+	movb	$0x08, %ah
+	int	$0x13
+	xorw	%ax, %ax
+	movb	%dh, %al	/* dh = number of heads */
+	incw	%ax		/* From 0-based to count */
+	pushw	%ax		/* Save heads on the stack */
+	andw	$0x3f, %cx	/* Sector count */
+	pushw	%cx		/* Save sectors on the stack */
+
+	xorl	%eax, %eax
+	pushl	%eax		/* Base */
+	pushl	%eax		/* Root */
+	call	scan_partition_table
+	
+	/* If we get here, we have no OS */
+	jmp	missing_os
+
+/*
+ * read_sector: read a single sector pointed to by %eax to 0x7c00.
+ * CF is set on error.  All registers clobbered.
+ */
+read_sector:
+read_sector_cbios:
+	movl	%eax, %edx
+	shrl	$16, %edx
+	divw	(sectors)
+	incw	%dx
+	movw	%dx, %cx
+	xorw	%dx, %dx
+	divw	(heads)
+	/* dx = head, ax = cylinder */
+	movb	%al, %ch
+	shrw	$2, %ax
+	shrw	%ax
+	andb	$0xc0, %al
+	orb	%al, %cl
+	movb	%dl, %dh
+	movw	$bootsec, %bx
+	movw	$0x0201, %ax
+	jmp	read_common
+read_sector_ebios:
+	movw	$dapa, %si
+	movl	%eax, 8(%si)
+	movb	$0x42, %ah
+read_common:
+	movb	(driveno), %dl
+	int	$0x13
+	ret
+
+/*
+ * read_partition_table:
+ *	Read a partition table (pointed to by %eax), and copy
+ *	the partition table into the ptab buffer.
+ *	Preserve registers.
+ */
+ptab	= _start+446
+
+read_partition_table:
+	pushal
+	call	read_sector
+	jc	20f
+	movw	$bootsec+446, %si
+	movw	$ptab, %di
+	movw	$(16*4/2), %cx
+	rep ; movsw
+20:
+	popal
+	ret
+			
+/*
+ * scan_partition_table:
+ *	Scan a partition table currently loaded in the partition table
+ *	area.  Preserve 16-bit registers.
+ *
+ *	On stack:
+ *	  18(%bp) - root (offset from MBR, or 0 for MBR)
+ *	  22(%bp) - base (location of this partition table)
+ */
+	
+scan_partition_table:
+	pusha
+	movw	%sp, %bp
+
+	/* Search for active partitions */	
+	movw	$ptab, %di
+	movw	$4, %cx
+	xorw	%ax, %ax
+5:
+	testb	$0x80, (%di)
+	jz 6f
+	incw	%ax
+	movw	%di, %si
+6:
+	addw	$16, %di
+	loopw	5b
+
+	cmpw	$1, %ax		/* Number of active partitions found */
+	je	boot
+	ja	too_many_active
+
+	/* No active partitions found, look for extended partitions */
+	movw	$ptab, %di
+	movb	$4, %cl		/* cx == 0 here */
+7:
+	movb	4(%di), %al
+	cmpb	$0x05, %al	/* MS-DOS extended */
+	je	8f
+	cmpb	$0x0f, %al	/* Win9x extended */
+	je	8f
+	cmpb	$0x85, %al	/* Linux extended */
+	jne	9f
+	
+	/* It is an extended partition.  Read the extended partition and
+	   try to scan it.  If the scan returns, re-load the current
+	   partition table and resume scan. */
+8:
+	movl	8(%di), %eax		/* Partition table offset */
+	movl	18(%bp), %edx		/* "Root" */
+	addl	%edx, %eax		/* Compute location of new ptab */
+	andl	%edx, %edx		/* Is this the MBR? */
+	jnz	10f
+	movl	%eax, %edx		/* Offset -> root if this was MBR */
+10:
+	pushl	%eax			/* Push new base */
+	pushl	%edx			/* Push new root */
+	call	read_partition_table
+	jc 11f
+	call	scan_partition_table
+11:
+	addw	$8, %sp
+	/* This returned, so we need to reload the current partition table */
+	movl	22(%bp), %eax
+	call	read_partition_table
+
+	/* fall through */		
+9:
+	/* Not an extended partition */
+	addw	$16, %di
+	loopw	7b
+
+	/* Nothing found, return */
+	popa
+	ret
+
+/*
+ * boot: invoke the actual bootstrap. (%si) points to the partition
+ *	 table entry, and 22(%bp) has the partition table base.
+ */
+boot:
+	movl	8(%si), %eax
+	addl	22(%bp), %eax
+	movl	%eax, 8(%si)
+	pushw	%si
+	call	read_sector
+	popw	%si
+	jc	disk_error
+	cmpw	$0xaa55, (bootsec+510)
+	jne	missing_os		/* Not a valid boot sector */
+	movw	$driveno, %sp
+	popw	%dx		/* dl -> drive number */
+	popw	%di		/* es:di -> $PnP vector */
+	popw	%es
+	cli
+	jmp	bootsec
+
+/*
+ * error messages
+ */
+missing_os:
+	movw	$missing_os_msg, %si
+	jmp	error
+disk_error:
+	movw	$disk_error_msg, %si
+	jmp	error
+too_many_active:
+	movw	$too_many_active_msg, %si
+	/* jmp error */
+	
+error:
+2:
+	lodsb
+	andb	%al, %al
+	jz	3f
+	movb	$0x0e, %ah
+	movb	(BIOS_page), %bh
+	movb	$0x07, %bl
+	int	$0x10
+	jmp	2b
+3:
+	int	$0x18		/* Boot failure */
+	jmp	.		/* Die */
+
+missing_os_msg:
+	.ascii	"Missing operating system."
+	.byte	0
+disk_error_msg:
+	.ascii	"Operating system load error."
+	.byte	0
+too_many_active_msg:
+	.ascii	"Multiple active partitions."
+	.byte	0
+
+	.balign	4
+dapa:
+	.short	16		/* Size of packet */
+	.short	1		/* Sector count */
+	.short	0x7c00		/* Buffer offset */
+	.short	0		/* Buffer segment */
+	.long	0		/* LSW of LBA */
+	.long	0		/* MSW of LBA */
diff --git a/mbr/mbr.ld b/mbr/mbr.ld
new file mode 100644
index 00000000..d14ba802
--- /dev/null
+++ b/mbr/mbr.ld
@@ -0,0 +1,73 @@
+/*
+ * Linker script for MBR
+ */
+
+/* Script for -z combreloc: combine and sort reloc sections */
+OUTPUT_FORMAT("elf32-i386", "elf32-i386",
+	      "elf32-i386")
+OUTPUT_ARCH(i386)
+EXTERN(_start)
+ENTRY(_start)
+SECTIONS
+{
+  /* Read-only sections, merged into text segment: */
+  . = 0x600;
+  .text           :
+  {
+    *(.text*)
+    *(.rodata*)
+  } =0x90909090
+
+  . = ALIGN(4);
+  .data		  :
+  {
+    *(.data*)
+  }
+
+  . = ALIGN(128);
+  .bss		  :
+  {
+    *(.bss*)
+  }
+
+  . = 0x7c00;
+  .bootsec	  :
+  {
+    *(.bootsec)
+  }
+
+  /* Stabs debugging sections.  */
+  .stab          0 : { *(.stab) }
+  .stabstr       0 : { *(.stabstr) }
+  .stab.excl     0 : { *(.stab.excl) }
+  .stab.exclstr  0 : { *(.stab.exclstr) }
+  .stab.index    0 : { *(.stab.index) }
+  .stab.indexstr 0 : { *(.stab.indexstr) }
+  .comment       0 : { *(.comment) }
+  /* DWARF debug sections.
+     Symbols in the DWARF debugging sections are relative to the beginning
+     of the section so we begin them at 0.  */
+  /* DWARF 1 */
+  .debug          0 : { *(.debug) }
+  .line           0 : { *(.line) }
+  /* GNU DWARF 1 extensions */
+  .debug_srcinfo  0 : { *(.debug_srcinfo) }
+  .debug_sfnames  0 : { *(.debug_sfnames) }
+  /* DWARF 1.1 and DWARF 2 */
+  .debug_aranges  0 : { *(.debug_aranges) }
+  .debug_pubnames 0 : { *(.debug_pubnames) }
+  /* DWARF 2 */
+  .debug_info     0 : { *(.debug_info .gnu.linkonce.wi.*) }
+  .debug_abbrev   0 : { *(.debug_abbrev) }
+  .debug_line     0 : { *(.debug_line) }
+  .debug_frame    0 : { *(.debug_frame) }
+  .debug_str      0 : { *(.debug_str) }
+  .debug_loc      0 : { *(.debug_loc) }
+  .debug_macinfo  0 : { *(.debug_macinfo) }
+  /* SGI/MIPS DWARF 2 extensions */
+  .debug_weaknames 0 : { *(.debug_weaknames) }
+  .debug_funcnames 0 : { *(.debug_funcnames) }
+  .debug_typenames 0 : { *(.debug_typenames) }
+  .debug_varnames  0 : { *(.debug_varnames) }
+  /DISCARD/ : { *(.note.GNU-stack) }
+}
diff --git a/mbr.asm b/mbr/oldmbr.asm
index 31bf1fdf..31bf1fdf 100644
--- a/mbr.asm
+++ b/mbr/oldmbr.asm
diff --git a/memdisk/Makefile b/memdisk/Makefile
index 1eebe637..72234cab 100644
--- a/memdisk/Makefile
+++ b/memdisk/Makefile
@@ -17,7 +17,7 @@ gcc_ok   = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
 
 M32     := $(call gcc_ok,-m32,)
 ALIGN   := $(call gcc_ok,-falign-functions=0 -falign-jumps=0 -falign-loops=0,-malign-functions=0 -malign-jumps=0 -malign-loops=0)
-FREE    := $(call gcc_ok,-ffreestanding,)
+FREE    := $(call gcc_ok,-ffreestanding,) $(call gcc_ok,-fno-stack-protector,)
 
 CC       = gcc
 CFLAGS   =  $(M32) $(FREE) -g -W -Wall -Wno-sign-compare \
diff --git a/memdisk/memdisk.asm b/memdisk/memdisk.asm
index 09055d8f..1d3d39de 100644
--- a/memdisk/memdisk.asm
+++ b/memdisk/memdisk.asm
@@ -6,7 +6,7 @@
 ;  A program to emulate an INT 13h disk BIOS from a "disk" in extended
 ;  memory.
 ;
-;   Copyright (C) 2001-2006  H. Peter Anvin
+;   Copyright (C) 2001-2007  H. Peter Anvin
 ;
 ;  This program is free software; you can redistribute it and/or modify
 ;  it under the terms of the GNU General Public License as published by
@@ -152,8 +152,8 @@ Int13Start:
 		mov bp,sp		; Point BP to the entry stack frame
 		TRACER 'F'
 		; Note: AH == P_AH here
-		cmp ah,Int13FuncsMax
-		jae Invalid_jump
+		cmp ah,[Int13MaxFunc]
+		ja Invalid_jump
 		xor al,al		; AL = 0 is standard entry condition
 		mov di,ax
 		shr di,7		; Convert AH to an offset in DI
@@ -870,7 +870,7 @@ Int13Funcs	dw Reset		; 00h - RESET
 %endif
 
 Int13FuncsEnd	equ $
-Int13FuncsMax	equ (Int13FuncsEnd-Int13Funcs) >> 1
+Int13FuncsCnt	equ (Int13FuncsEnd-Int13Funcs) >> 1
 
 %if EDD
 EDD_DPT:
@@ -933,8 +933,9 @@ OldInt15	dd 0			; INT 15h in chain
 OldDosMem	dw 0			; Old position of DOS mem end
 BootLoaderID	db 0			; Boot loader ID from header
 ; ---- MDI structure ends here ---
-		db 0, 0, 0		; pad
+Int13MaxFunc	db Int13FuncsCnt-1	; Max INT 13h function (to disable EDD)
 
+		db 0, 0			; pad
 MemInt1588	dw 0			; 1MB-65MB memory amount (1K)
 
 Cylinders	dw 0			; Cylinder count
diff --git a/memdisk/memdisk.doc b/memdisk/memdisk.doc
index fdcc259e..759a7b27 100644
--- a/memdisk/memdisk.doc
+++ b/memdisk/memdisk.doc
@@ -89,6 +89,12 @@ d) MEMDISK normally uses the BIOS "INT 15h mover" API to access high
    safeint	Use INT 15h access to protected memory, but invoke
 		INT 15h the way it was *before* MEMDISK was loaded.
 
+e) MEMDISK by default supports EDD/EBIOS on hard disks, but not on
+   floppy disks.  This can be controlled with the options:
+
+   edd		Enable EDD/EBIOS
+   noedd	Disable EDD/EBIOS
+
 
 Some interesting things to note:
 
@@ -136,7 +142,7 @@ http://www.ctyme.com/rbrown.htm, for a detailed description.
 
 The MEMDISK info structure currently contains:
 
-	[ES:DI]		word	Total size of structure (currently 27 bytes)
+	[ES:DI]		word	Total size of structure (currently 28 bytes)
 	[ES:DI+2]	byte	MEMDISK minor version
 	[ES:DI+3]	byte	MEMDISK major version
 	[ES:DI+4]	dword	Pointer to MEMDISK data in high memory
diff --git a/memdisk/setup.c b/memdisk/setup.c
index 8c83f039..d1eabc58 100644
--- a/memdisk/setup.c
+++ b/memdisk/setup.c
@@ -70,8 +70,10 @@ struct patch_area {
 
   uint16_t olddosmem;
   uint8_t  bootloaderid;
+  uint8_t  maxint13func;
+#define MAXINT13_NOEDD	0x16
 
-  uint8_t  _pad[3];
+  uint8_t  _pad[2];
   uint16_t memint1588;
 
   uint16_t cylinders;
@@ -552,6 +554,7 @@ void setup(syscall_t cs_syscall, void *cs_bounce)
   com32sys_t regs;
   uint32_t ramdisk_image, ramdisk_size;
   int bios_drives;
+  int do_edd = -1;		/* -1 = default, 0 = no, 1 = yes */
 
   /* Set up global variables */
   syscall = cs_syscall;
@@ -579,11 +582,22 @@ void setup(syscall_t cs_syscall, void *cs_bounce)
 
   geometry = get_disk_image_geometry(ramdisk_image, ramdisk_size);
 
-  printf("Disk is %s %d, %u K, C/H/S = %u/%u/%u\n",
+  if (getcmditem("edd") != CMD_NOTFOUND ||
+      getcmditem("ebios") != CMD_NOTFOUND)
+    do_edd = 1;
+  else if (getcmditem("noedd") != CMD_NOTFOUND ||
+	   getcmditem("noebios") != CMD_NOTFOUND ||
+	   getcmditem("cbios") != CMD_NOTFOUND)
+    do_edd = 0;
+  else
+    do_edd = (geometry->driveno & 0x80) ? 1 : 0;
+
+  printf("Disk is %s %d, %u K, C/H/S = %u/%u/%u, EDD %s\n",
 	 (geometry->driveno & 0x80) ? "hard disk" : "floppy",
 	 geometry->driveno & 0x7f,
 	 geometry->sectors >> 1,
-	 geometry->c, geometry->h, geometry->s);
+	 geometry->c, geometry->h, geometry->s,
+	 do_edd ? "on" : "off");
 
   /* Reserve the ramdisk memory */
   insertrange(ramdisk_image, ramdisk_size, 2);
@@ -633,6 +647,10 @@ void setup(syscall_t cs_syscall, void *cs_bounce)
     pptr->configflags |= CONFIG_BIGRAW|CONFIG_RAW;
   }
 
+  /* pptr->maxint13func defaults to EDD enabled, if compiled in */
+  if (!do_edd)
+    pptr->maxint13func = MAXINT13_NOEDD;
+
   /* Set up a drive parameter table */
   if ( geometry->driveno & 0x80 ) {
     /* Hard disk */
diff --git a/menu/Makefile b/menu/Makefile
index 91a8697e..cee1c3af 100644
--- a/menu/Makefile
+++ b/menu/Makefile
@@ -17,7 +17,7 @@
 gcc_ok   = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
 	           then echo $(1); else echo $(2); fi)
 
-M32     := $(call gcc_ok,-m32,)
+M32     := $(call gcc_ok,-m32,) $(call gcc_ok,-fno-stack-protector,)
 
 CC         = gcc
 LD         = ld -m elf_i386
diff --git a/mtools/Makefile b/mtools/Makefile
index 26909a30..546e3d14 100644
--- a/mtools/Makefile
+++ b/mtools/Makefile
@@ -1,8 +1,14 @@
+gcc_ok   = $(shell if gcc $(1) ../dummy.c -o /dev/null 2>/dev/null; \
+	           then echo '$(1)'; else echo '$(2)'; fi)
+
+comma   := ,
+LDHASH  := $(call gcc_ok,-Wl$(comma)--hash-style=both,)
+
 CC	 = gcc
 OPTFLAGS = -g -Os
 INCLUDES = -I. -I.. -I../libfat
 CFLAGS	 = -W -Wall -D_FILE_OFFSET_BITS=64 $(OPTFLAGS) $(INCLUDES)
-LDFLAGS	 = -s
+LDFLAGS	 = $(LDHASH) -s
 
 SRCS     = syslinux.c ../syslxmod.c ../bootsect_bin.c ../ldlinux_bin.c $(wildcard ../libfat/*.c)
 OBJS	 = $(patsubst %.c,%.o,$(notdir $(SRCS)))
diff --git a/mtools/syslinux.c b/mtools/syslinux.c
index 29259dff..e65b081f 100644
--- a/mtools/syslinux.c
+++ b/mtools/syslinux.c
@@ -210,7 +210,7 @@ int main(int argc, char *argv[])
     exit(1);
   }
   fprintf(mtc,
-	  "MTOOLS_NO_VFAT=1\n"
+	  /* "MTOOLS_NO_VFAT=1\n" */
 	  "MTOOLS_SKIP_CHECK=1\n" /* Needed for some flash memories */
 	  "drive s:\n"
 	  "  file=\"/proc/%lu/fd/%d\"\n"
diff --git a/sample/Makefile b/sample/Makefile
index e24ab5be..bacc57ca 100644
--- a/sample/Makefile
+++ b/sample/Makefile
@@ -17,7 +17,7 @@
 gcc_ok   = $(shell if gcc $(1) -c -x c /dev/null -o /dev/null 2>/dev/null; \
 	           then echo $(1); else echo $(2); fi)
 
-M32       := $(call gcc_ok,-m32,) $(call gcc_ok,-ffreestanding,)
+M32       := $(call gcc_ok,-m32,) $(call gcc_ok,-ffreestanding,) $(call gcc_ok,-fno-stack-protector,)
 
 CC         = gcc
 LD         = ld -m elf_i386
diff --git a/ui.inc b/ui.inc
index 5c1e7302..b5eed64a 100644
--- a/ui.inc
+++ b/ui.inc
@@ -324,10 +324,6 @@ vk_check:
 ; Find the kernel on disk
 ;
 get_kernel:     mov byte [KernelName+FILENAME_MAX],0	; Zero-terminate filename/extension
-%if IS_SYSLINUX || IS_MDSLINUX			; SYSLINUX has to deal with DOS mangled names...
-		mov eax,[KernelName+8]		; Save initial extension
-		mov [exten_table_end],eax	; Last case == initial ext.
-%else
 		mov di,KernelName+4*IS_PXELINUX
 		xor al,al
 		mov cx,FILENAME_MAX-5		; Need 4 chars + null
@@ -335,7 +331,6 @@ get_kernel:     mov byte [KernelName+FILENAME_MAX],0	; Zero-terminate filename/e
 		jne .no_skip
 		dec di				; Point to final null
 .no_skip:	mov [KernelExtPtr],di
-%endif
 		mov bx,exten_table
 .search_loop:	push bx
                 mov di,KernelName	      	; Search on disk
@@ -343,13 +338,9 @@ get_kernel:     mov byte [KernelName+FILENAME_MAX],0	; Zero-terminate filename/e
 		pop bx
                 jnz kernel_good
 		mov eax,[bx]			; Try a different extension
-%if IS_SYSLINUX || IS_MDSLINUX
-		mov [KernelName+8],eax
-%else
 		mov si,[KernelExtPtr]
 		mov [si],eax
 		mov byte [si+4],0
-%endif
 		add bx,byte 4
 		cmp bx,exten_table_end
 		jna .search_loop		; allow == case (final case)
@@ -493,10 +484,6 @@ kernel_good:
 		mov [KernelCNameLen],di
 		popa
 
-%if IS_SYSLINUX || IS_MDSLINUX
-		mov ecx,[KernelName+7]
-		mov cl,'.'
-%else
 		push di
 		push ax
 		mov di,KernelName+4*IS_PXELINUX
@@ -508,7 +495,6 @@ kernel_good:
 .one_step:	mov ecx,[di-4]			; 4 bytes before end
 		pop ax
 		pop di
-%endif
 
 ;
 ; At this point, DX:AX contains the size of the kernel, SI contains
@@ -535,19 +521,13 @@ is_unknown_filetype:
 		je is_bss_sector
 		cmp ecx,'.bin'
 		je is_bootsector
-%if IS_SYSLINUX || IS_MDSLINUX
-		cmp ecx,'.bs '
-		je is_bootsector
-		cmp ecx,'.0  '
-		je is_bootsector
-%else
 		shr ecx,8
 		cmp ecx,'.bs'
 		je is_bootsector
 		shr ecx,8
 		cmp cx,'.0'
 		je is_bootsector
-%endif
+
 		; Otherwise Linux kernel
 		jmp is_linux_kernel
 
diff --git a/unix/Makefile b/unix/Makefile
index 5dfc0513..f0ab279a 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -1,10 +1,16 @@
+gcc_ok   = $(shell if gcc $(1) ../dummy.c -o /dev/null 2>/dev/null; \
+	           then echo '$(1)'; else echo '$(2)'; fi)
+
+comma   := ,
+LDHASH  := $(call gcc_ok,-Wl$(comma)--hash-style=both,)
+
 CC	 = gcc
 OPTFLAGS = -g -Os
-INCLUDES = -I. -I.. -I../libfat
+INCLUDES = -I. -I..
 CFLAGS	 = -W -Wall -D_FILE_OFFSET_BITS=64 $(OPTFLAGS) $(INCLUDES)
-LDFLAGS	 = -s
+LDFLAGS	 = $(LDHASH) -s
 
-SRCS     = syslinux.c ../syslxmod.c ../bootsect_bin.c ../ldlinux_bin.c $(wildcard ../libfat/*.c)
+SRCS     = syslinux.c ../syslxmod.c ../bootsect_bin.c ../ldlinux_bin.c
 OBJS	 = $(patsubst %.c,%.o,$(notdir $(SRCS)))
 
 .SUFFIXES: .c .o .i .s .S
diff --git a/unix/syslinux.c b/unix/syslinux.c
index 36826a1b..4270d728 100644
--- a/unix/syslinux.c
+++ b/unix/syslinux.c
@@ -13,7 +13,7 @@
 /*
  * syslinux.c - Linux installer program for SYSLINUX
  *
- * This program ought to be portable.  I hope so, at least.
+ * This is Linux-specific by now.
  *
  * This is an alternate version of the installer which doesn't require
  * mtools, but requires root privilege.
@@ -46,23 +46,28 @@
 #include <sys/wait.h>
 #include <sys/mount.h>
 
+#include <sys/ioctl.h>
+#include <linux/fs.h>		/* FIGETBSZ, FIBMAP */
+#include <linux/msdos_fs.h>	/* FAT_IOCTL_SET_ATTRIBUTES, SECTOR_* */
+#ifndef FAT_IOCTL_SET_ATTRIBUTES
+# define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, uint32_t)
+#endif
+
+#include <paths.h>
+#ifndef _PATH_MOUNT
+# define _PATH_MOUNT "/bin/mount"
+#endif
+#ifndef _PATH_UMOUNT
+# define _PATH_UMOUNT "/bin/umount"
+#endif
+#ifndef _PATH_TMP
+# define _PATH_TMP "/tmp/"
+#endif
+
 #include "syslinux.h"
-#include "libfat.h"
 
 #if DO_DIRECT_MOUNT
-
 # include <linux/loop.h>
-
-#else
-
-# include <paths.h>
-# ifndef _PATH_MOUNT
-#  define _PATH_MOUNT "/bin/mount"
-# endif
-# ifndef _PATH_UMOUNT
-#  define _PATH_UMOUNT "/bin/umount"
-# endif
-
 #endif
 
 const char *program;		/* Name of program */
@@ -156,35 +161,175 @@ ssize_t xpwrite(int fd, const void *buf, size_t count, off_t offset)
 }
 
 /*
- * Version of the read function suitable for libfat
+ * Create a block map for ldlinux.sys
+ */
+int make_block_map(uint32_t *sectors, int len, int dev_fd, int fd)
+{
+  int nsectors = 0;
+  int blocksize, nblock, block;
+  int i;
+
+  (void)dev_fd;
+
+  if (ioctl(fd, FIGETBSZ, &blocksize) < 0)
+    die("ioctl FIGETBSZ failed");
+
+  blocksize >>= SECTOR_BITS;	/* sectors/block */
+
+  nblock = 0;
+  while (len > 0) {
+    block = nblock++;
+    if (ioctl(fd, FIBMAP, &block) < 0)
+      die("ioctl FIBMAP failed");
+    
+    for (i = 0; i < blocksize; i++) {
+      if (len <= 0)
+	break;
+
+      *sectors++ = (block*blocksize)+i;
+      nsectors++;
+      len -= (1 << SECTOR_BITS);
+    }
+  }
+
+  return nsectors;
+}
+
+/*
+ * Mount routine
+ */
+int do_mount(int dev_fd, int *cookie, const char *mntpath, const char *fstype)
+{
+  struct stat st;
+
+  (void)cookie;
+
+  if (fstat(dev_fd, &st) < 0)
+    return errno;
+
+#if DO_DIRECT_MOUNT
+  {
+    if ( !S_ISBLK(st.st_mode) ) {
+      /* It's file, need to mount it loopback */
+      unsigned int n = 0;
+      struct loop_info64 loopinfo;
+      int loop_fd;
+      
+      for ( n = 0 ; loop_fd < 0 ; n++ ) {
+	snprintf(devfdname, sizeof devfdname, "/dev/loop%u", n);
+	loop_fd = open(devfdname, O_RDWR);
+	if ( loop_fd < 0 && errno == ENOENT ) {
+	  die("no available loopback device!");
+	}
+	if ( ioctl(loop_fd, LOOP_SET_FD, (void *)dev_fd) ) {
+	  close(loop_fd); loop_fd = -1;
+	  if ( errno != EBUSY )
+	    die("cannot set up loopback device");
+	  else
+	    continue;
+	}
+	
+	if ( ioctl(loop_fd, LOOP_GET_STATUS64, &loopinfo) ||
+	     (loopinfo.lo_offset = filesystem_offset,
+	      ioctl(loop_fd, LOOP_SET_STATUS64, &loopinfo)) )
+	  die("cannot set up loopback device");
+      }
+      
+      *cookie = loop_fd;
+    } else {
+      snprintf(devfdname, sizeof devfdname, "/proc/%lu/fd/%d",
+	       (unsigned long)mypid, dev_fd);
+      *cookie = -1;
+    }   
+    
+    return mount(devfdname, mntpath, fstype,
+		 MS_NOEXEC|MS_NOSUID, "umask=077,quiet");
+  }
+#else
+  {
+    char devfdname[128], mnt_opts[128];
+    pid_t f, w;
+    int status;
+
+    snprintf(devfdname, sizeof devfdname, "/proc/%lu/fd/%d",
+	     (unsigned long)mypid, dev_fd);
+    
+    f = fork();
+    if ( f < 0 ) {
+      return -1;
+    } else if ( f == 0 ) {
+      if ( !S_ISBLK(st.st_mode) ) {
+	snprintf(mnt_opts, sizeof mnt_opts,
+		 "rw,nodev,noexec,loop,offset=%llu,umask=077,quiet",
+		 (unsigned long long)filesystem_offset);
+      } else {
+	snprintf(mnt_opts, sizeof mnt_opts, "rw,nodev,noexec,umask=077,quiet");
+      }
+      execl(_PATH_MOUNT, _PATH_MOUNT, "-t", fstype, "-o", mnt_opts,	\
+	    devfdname, mntpath, NULL);
+      _exit(255);		/* execl failed */
+    }
+    
+    w = waitpid(f, &status, 0);
+    return ( w != f || status ) ? -1 : 0;
+  }
+#endif
+}
+
+/*
+ * umount routine
  */
-int libfat_xpread(intptr_t pp, void *buf, size_t secsize, libfat_sector_t sector)
+void do_umount(const char *mntpath, int cookie)
 {
-  off_t offset = (off_t)sector * secsize + filesystem_offset;
-  return xpread(pp, buf, secsize, offset);
+#if DO_DIRECT_MOUNT
+  int loop_fd = cookie;
+  
+  if ( umount2(mntpath, 0) )
+    die("could not umount path");
+  
+  if ( loop_fd != -1 ) {
+    ioctl(loop_fd, LOOP_CLR_FD, 0); /* Free loop device */
+    close(loop_fd);
+    loop_fd = -1;
+  }
+  
+#else
+  pid_t f = fork();
+  pid_t w;
+  int status;
+  (void)cookie;
+
+  if ( f < 0 ) {
+    perror("fork");
+    exit(1);
+  } else if ( f == 0 ) {
+    execl(_PATH_UMOUNT, _PATH_UMOUNT, mntpath, NULL);
+  }
+  
+  w = waitpid(f, &status, 0);
+  if ( w != f || status ) {
+    exit(1);
+  }
+#endif
 }
 
 int main(int argc, char *argv[])
 {
-  static unsigned char sectbuf[512];
+  static unsigned char sectbuf[SECTOR_SIZE];
   unsigned char *dp;
   const unsigned char *cdp;
   int dev_fd, fd;
   struct stat st;
   int nb, left;
   int err = 0;
-  pid_t f, w;
-  int status;
-  char mntname[64], devfdname[64];
+  char mntname[128];
   char *ldlinux_name, **argp, *opt;
   int force = 0;		/* -f (force) option */
   const char *subdir = NULL;
-  struct libfat_filesystem *fs;
-  struct libfat_direntry dentry;
-  libfat_sector_t s, *secp, sectors[65]; /* 65 is maximum possible */
-  int32_t ldlinux_cluster;
+  uint32_t sectors[65]; /* 65 is maximum possible */
   int nsectors = 0;
   const char *errmsg;
+  int mnt_cookie;
 
   (void)argc;			/* Unused */
 
@@ -209,7 +354,8 @@ int main(int argc, char *argv[])
 	} else if ( *opt == 'd' && argp[1] ) {
 	  subdir = *++argp;
 	} else if ( *opt == 'o' && argp[1] ) {
-	  filesystem_offset = (off_t)strtoull(*++argp, NULL, 0); /* Byte offset */
+	  /* Byte offset */
+	  filesystem_offset = (off_t)strtoull(*++argp, NULL, 0);
 	} else {
 	  usage();
 	}
@@ -235,15 +381,15 @@ int main(int argc, char *argv[])
     exit(1);
   }
 
-  if ( !force && !S_ISBLK(st.st_mode) && !S_ISREG(st.st_mode) ) {
-    die("not a block device or regular file (use -f to override)");
+  if ( !S_ISBLK(st.st_mode) && !S_ISREG(st.st_mode) && !S_ISCHR(st.st_mode) ) {
+    die("not a device or regular file");
   }
 
-  if ( !force && filesystem_offset && !S_ISREG(st.st_mode) ) {
-    die("not a regular file and an offset specified (use -f to override)");
+  if ( filesystem_offset && S_ISBLK(st.st_mode) ) {
+    die("can't combine an offset with a block device");
   }
 
-  xpread(dev_fd, sectbuf, 512, filesystem_offset);
+  xpread(dev_fd, sectbuf, SECTOR_SIZE, filesystem_offset);
   fsync(dev_fd);
 
   /*
@@ -267,7 +413,7 @@ int main(int argc, char *argv[])
     /* We're root or at least setuid.
        Make a temp dir and pass all the gunky options to mount. */
 
-    if ( chdir("/tmp") ) {
+    if ( chdir(_PATH_TMP) ) {
       perror(program);
       exit(1);
     }
@@ -276,7 +422,7 @@ int main(int argc, char *argv[])
 
     if ( stat(".", &dst) || !S_ISDIR(dst.st_mode) ||
 	 (dst.st_mode & TMP_MODE) != TMP_MODE ) {
-      die("possibly unsafe /tmp permissions");
+      die("possibly unsafe " _PATH_TMP " permissions");
     }
 
     for ( i = 0 ; ; i++ ) {
@@ -303,80 +449,29 @@ int main(int argc, char *argv[])
     }
 
     mntpath = mntname;
+  }
 
-#if DO_DIRECT_MOUNT
-    if ( S_ISREG(st.st_mode) ) {
-      /* It's file, need to mount it loopback */
-      unsigned int n = 0;
-      struct loop_info64 loopinfo;
-
-      for ( n = 0 ; loop_fd < 0 ; n++ ) {
-	snprintf(devfdname, sizeof devfdname, "/dev/loop%u", n);
-	loop_fd = open(devfdname, O_RDWR);
-	if ( loop_fd < 0 && errno == ENOENT ) {
-	  die("no available loopback device!");
-	}
-	if ( ioctl(loop_fd, LOOP_SET_FD, (void *)dev_fd) ) {
-	  close(loop_fd); loop_fd = -1;
-	  if ( errno != EBUSY )
-	    die("cannot set up loopback device");
-	  else
-	    continue;
-	}
-
-	if ( ioctl(loop_fd, LOOP_GET_STATUS64, &loopinfo) ||
-	     (loopinfo.lo_offset = filesystem_offset,
-	      ioctl(loop_fd, LOOP_SET_STATUS64, &loopinfo)) )
-	  die("cannot set up loopback device");
-      }
-    } else {
-      snprintf(devfdname, sizeof devfdname, "/proc/%lu/fd/%d",
-	       (unsigned long)mypid, dev_fd);
-    }
-
-    if ( mount(devfdname, mntpath, "msdos",
-	       MS_NOEXEC|MS_NOSUID, "umask=077,quiet") )
-      die("could not mount filesystem");
-
-#else
-
-    snprintf(devfdname, sizeof devfdname, "/proc/%lu/fd/%d",
-	     (unsigned long)mypid, dev_fd);
-
-    f = fork();
-    if ( f < 0 ) {
-      perror(program);
-      rmdir(mntpath);
-      exit(1);
-    } else if ( f == 0 ) {
-      char mnt_opts[128];
-      if ( S_ISREG(st.st_mode) ) {
-	snprintf(mnt_opts, sizeof mnt_opts, "rw,nodev,noexec,loop,offset=%llu,umask=077,quiet",
-		 (unsigned long long)filesystem_offset);
-      } else {
-	snprintf(mnt_opts, sizeof mnt_opts, "rw,nodev,noexec,umask=077,quiet");
-      }
-      execl(_PATH_MOUNT, _PATH_MOUNT, "-t", "msdos", "-o", mnt_opts,\
-	    devfdname, mntpath, NULL);
-      _exit(255);		/* execl failed */
-    }
-
-    w = waitpid(f, &status, 0);
-    if ( w != f || status ) {
-      rmdir(mntpath);
-      exit(1);			/* Mount failed */
-    }
-
-#endif
+  if (do_mount(dev_fd, &mnt_cookie, mntpath, "vfat") &&
+      do_mount(dev_fd, &mnt_cookie, mntpath, "msdos")) {
+    rmdir(mntpath);
+    die("mount failed");
   }
 
-  ldlinux_name = alloca(strlen(mntpath)+14);
+  ldlinux_name = alloca(strlen(mntpath)+14+
+			(subdir ? strlen(subdir)+2 : 0));
   if ( !ldlinux_name ) {
     perror(program);
     err = 1;
     goto umount;
   }
-  sprintf(ldlinux_name, "%s//ldlinux.sys", mntpath);
+  sprintf(ldlinux_name, "%s%s%s//ldlinux.sys",
+	  mntpath, subdir ? "//" : "", subdir ? subdir : "");
+
+  if ((fd = open(ldlinux_name, O_RDONLY)) >= 0) {
+    uint32_t zero_attr = 0;
+    ioctl(fd, FAT_IOCTL_SET_ATTRIBUTES, &zero_attr);
+    close(fd);
+  }
 
   unlink(ldlinux_name);
   fd = open(ldlinux_name, O_WRONLY|O_CREAT|O_TRUNC, 0444);
@@ -402,81 +497,25 @@ int main(int argc, char *argv[])
     left -= nb;
   }
 
+  fsync(fd);
   /*
-   * I don't understand why I need this.  Does the DOS filesystems
-   * not honour the mode passed to open()?
+   * Set the attributes
    */
-  fchmod(fd, 0400);
-
-  close(fd);
-
-  sync();
+  {
+    uint32_t attr = 0x07;	/* Hidden+System+Readonly */
+    ioctl(fd, FAT_IOCTL_SET_ATTRIBUTES, &attr);
+  }
 
   /*
-   * Now, use libfat to create a block map.  This probably
-   * should be changed to use ioctl(...,FIBMAP,...) since
-   * this is supposed to be a simple, privileged version
-   * of the installer.
+   * Create a block map.
    */
-  fs = libfat_open(libfat_xpread, dev_fd);
-  ldlinux_cluster = libfat_searchdir(fs, 0, "LDLINUX SYS", &dentry);
-  secp = sectors;
-  nsectors = 0;
-  s = libfat_clustertosector(fs, ldlinux_cluster);
-  while ( s && nsectors < 65 ) {
-    *secp++ = s;
-    nsectors++;
-    s = libfat_nextsector(fs, s);
-  }
-  libfat_close(fs);
-
-  /* Move ldlinux.sys to the desired location */
-  if (subdir) {
-    char *new_ldlinux_name = alloca(strlen(mntpath)+
-				    strlen(subdir)+15);
-    int mov_err = 1;
+  nsectors = make_block_map(sectors, syslinux_ldlinux_len, dev_fd, fd);
 
-    if ( new_ldlinux_name ) {
-      sprintf(new_ldlinux_name, "%s//%s//ldlinux.sys", mntpath, subdir);
-
-      if (!rename(ldlinux_name, new_ldlinux_name))
-	mov_err = 0;
-    }
-
-    if (mov_err)
-      fprintf(stderr, "%s: warning: unable to move ldlinux.sys: %s\n",
-	      device, strerror(errno));
-  }
+  close(fd);
+  sync();
 
 umount:
-#if DO_DIRECT_MOUNT
-
-  if ( umount2(mntpath, 0) )
-    die("could not umount path");
-
-  if ( loop_fd != -1 ) {
-    ioctl(loop_fd, LOOP_CLR_FD, 0); /* Free loop device */
-    close(loop_fd);
-    loop_fd = -1;
-  }
-
-#else
-
-  f = fork();
-  if ( f < 0 ) {
-    perror("fork");
-    exit(1);
-  } else if ( f == 0 ) {
-    execl(_PATH_UMOUNT, _PATH_UMOUNT, mntpath, NULL);
-  }
-
-  w = waitpid(f, &status, 0);
-  if ( w != f || status ) {
-    exit(1);
-  }
-
-#endif
-
+  do_umount(mntpath, mnt_cookie);
   sync();
   rmdir(mntpath);
 
@@ -491,29 +530,21 @@ umount:
   /*
    * Write the now-patched first sector of ldlinux.sys
    */
-  xpwrite(dev_fd, syslinux_ldlinux, 512, filesystem_offset + ((off_t)sectors[0] << 9));
-
-  /*
-   * Patch the root directory to set attributes to
-   * HIDDEN|SYSTEM|READONLY
-   */
-  {
-    const unsigned char attrib = 0x07;
-    xpwrite(dev_fd, &attrib, 1, ((off_t)dentry.sector << 9)+dentry.offset+11);
-  }
+  xpwrite(dev_fd, syslinux_ldlinux, SECTOR_SIZE,
+	  filesystem_offset+((off_t)sectors[0] << SECTOR_BITS));
 
   /*
    * To finish up, write the boot sector
    */
 
   /* Read the superblock again since it might have changed while mounted */
-  xpread(dev_fd, sectbuf, 512, filesystem_offset);
+  xpread(dev_fd, sectbuf, SECTOR_SIZE, filesystem_offset);
 
   /* Copy the syslinux code into the boot sector */
   syslinux_make_bootsect(sectbuf);
 
   /* Write new boot sector */
-  xpwrite(dev_fd, sectbuf, 512, filesystem_offset);
+  xpwrite(dev_fd, sectbuf, SECTOR_SIZE, filesystem_offset);
 
   close(dev_fd);
   sync();