Starting with 1.47, changes marked with SYSLINUX/PXELINUX/ISOLINUX apply to that specific program only; other changes apply to all derivatives.

• Clean up garbage after aborted. message.
• Clean up memdump.com filenames.
• Support SHA256 and SHA512 encrypted passwords.
• The shuffle library now can generate chained descriptors, thus allowing pretty much arbitrarily complex memory maps.
• Handle command lines up to 2047 characters, the current Linux kernel limit.
• vesamenu: support systems without linear framebuffer support (sigh, what is this, 1993?) and 15-bit RGB modes.
• Move the label storage (for the command-line interface) to high memory, removing the size limit and freeing up 64K of low memory.
• Get rid of 4096-entry limit in the simple menu system.
• New hierarchial submenu support: see MENU BEGIN, MENU END, MENU GOTO in doc/menu.txt.
• MENU QUIT allows creating a menu entry for returning to the command line.
• ISOLINUX: Work around bug in certain Adaptec BIOSes, patch by Bruce Robson.
• pngtopnm dependency removed from samples/ directory.
• Text documentation files (in doc/) renamed *.doc -> *.txt.

Changes in 3.61:

• EXTLINUX: fix crash when accessing an empty file.
• elf.c32: If a PHDR segment is present, load it.
• Fix SHA-1 and MD5 passwords.
• ISOLINUX: fix booting when mastered without mkisofs -boot-info-table (broken since 3.50, sigh...)
• Handle BIOSes which emit multiple contiguous valid memory regions in the e820 map.

Changes in 3.60:

• Support for "auxilliary data vector", a small amount of writable storage. Currently only supported for EXTLINUX, but the infrastructure is there for the other derivatives, assuming a suitable storage location can be found.
• EXTLINUX: boot-once support (--once, --clear-once, and --reset-adv).
• A command is now required to the EXTLINUX installer, i.e. at least one of --install, --update, --once, --clear-once, or --reset-adv.

Changes in 3.55:

• PXELINUX: as per RFC 5071 PXELINUX no longer requires the use of the magic cookie option (208) for unencapsulated options. Currently it does not require it for vendor-encapsulated options (vendor-option-space) either, but that MAY be reverted in the future if it causes problems.
• Documentation text files moved to a common doc directory; man pages from the Debian project added to the man directory.
• Correct bug with self-overlapping memory areas when using the shuffle interface.

Changes in 3.54:

• Add menu separator, menu indent, menu disabled (see README.menu).
• vesamenu: fix handing of VESA modes with noncontiguous memory buffers. In particular, Qemu/KVM sets up such a mode when Cirrus Logic emulation is enabled (which is the default.)
• Support for calling real mode functions using far calls, with argument on the stack. This was implemented to support the BIOS BBS specification, but subsequent experiments show that the at least one of the most common BIOS cores, Award, passes the presence check but doesn't actually implement the functionality.

Changes in 3.53:

• Fix bugs related to the $PnP BIOS functionality on some platforms.
• PXELINUX: Fix the "naked" version of :: (suppress prefix.)
• elf.c32: better error messages.
• Faster operation under Intel VT virtualization.
• PXELINUX: Fix DHCP bootfile option.
• mkdiskimage: Support more than 1024 cylinders.
• (Hopefully) fix installer on non-x86 platforms.
• Fix shuffle_and_boot_rm, used by linux.c32.
• Fix shuffle_and_boot_pm on 386/486.
• ISOLINUX (at least): fix bss memory overwrite hang.
• MBR: Fix booting from logical partitions.
• Code cleanups.

Changes in 3.52:

• Handle capitalized F-key commands in the menu system.
• Fix padding error when loading multiple ramdisks.
• Workaround for VMware crashing when trying to print a message during early kernel boot (does not seem to work, consider deleting.)
• chain.c32: add the ability to search for a specific MBR signature at runtime.
• Fall back to the server identity option if the siaddr field in the DHCP header isn't set. This seems to match the behaviour of most PXE stacks.
• mkdiskimage: give the generated disk image an MBR signature.
• MEMDISK: Fix failures on some BIOSes.
• Simple menu system: new "MENU HIDDEN" option to not display the menu unless the user presses a key.
• Simple menu system: support MD5-encrypted passwords (modern Unix standard style, with "$1$" prefixes.)
• pcitest.c32: now functions as a full "lspci". Thanks to Erwan Velu for this work.
• MEMDISK: Make EDD actually work.
• ISOLINUX: Fix for certain broken CD-ROM BIOSes which randomly corrupted register FS.
• Simple menu system: fix memory overwrite bug that caused some systems to lock up or behave weirdly.
• Fix building on 64-bit systems without a 32-bit libc installed.

Changes in 3.51:

• EXTLINUX: Fix failure to find the configuration file.

• New keywords allow the type of file to be specified in the configuration file.
• It is now supported to load a different configuration file with the CONFIG keyword.
• Fix API call 0x0019 (Read Disk.)
• MENU AUTOBOOT, MENU TABMSG, MENU PASSPROMPT allows internationalization of menu messages.
• A new feature, TEXT HELP, allows the administrator to set a multi-line help message for individual selections.
• Fix API call 0x0012 (Cleanup, shuffle and boot.)
• New API call "Cleanup, shuffle and boot to flat protected mode"
• New API call "Cleanup, shuffle and boot to real mode", similar to API call 0x0012 but allows arbitrary register setting.
• Introduce a library interface for loading arbitrary binary formats with relatively easily understood code. See the elf.c32 module for an example on how to use it.
• New module elf.c32, to load a protected-mode ELF kernel.
• MBR (old and new): Fix bug in CHS mode when LBA > 65535*sectors.
• vesamenu: fix decoding of palettized PNG images.
• Update the Linux kernel boot protocol.
• PXELINUX: Press Ctrl-N at the boot prompt to read out the network info.
• Instead of the (non-existent) MAC, use the client identifier for networks like Infiniband and Firewire/1394.
• Add a new INCLUDE command to the core syslinux parser.
• Allow binding help text to F11 and F12.
• F-key help now available in the simple menu system.
• Disabled the polling for ARP during idle. It is simply too slow on some (broken!) PXE stacks.
• PXELINUX: also try to fetch the config file based on UUID.
• SYSLINUX/EXTLINUX: New RAID mode (-r) which calls the BIOS to load the next device (typically the next drive) on boot failure.

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.
• MEMDISK: Turn on EDD support by default.
• MEMDISK: Try to work on some machines on which it would not work when there was no floppy drive in the system.
• Simple menu system: fix serial console support (broken in 3.30).
• SYSLINUX: Support subdirectories. Like ISOLINUX, the "current directory" is the directory in which syslinux.cfg is found; this is searched for in the sequence /boot/syslinux, /syslinux, /. As a side benefit, label names like linux-2.6.18 and linux-2.6.19 are now supported. To install ldlinux.sys in a subdirectory, pass the -d directory option to the SYSLINUX installer. This work was sponsored by slax.org (thanks, Tomas!)
• New API call: read disk.
• Invoke ONERROR on initrd load failure.

Changes in 3.31:

• The simple menu system (menu.c32 and vesamenu.c32) now support loading more than one configuration file at a time, using MENU INCLUDE or by specifying multiple filenames.
• The MENU COLOR statement can now control the shadowing mode.

Changes in 3.30:

• libcom32 extended to support graphics mode and graphical console.
• vesamenu.c32, new graphical version of the Simple Menu System, see README.menu.
• New com32 modules by Erwan Velu do selection based on CPUID or PCI devices present.
• RPM spec: add syslinux-tftpboot module; move syslinux by default to the /usr/share/syslinux directory.
• RPM spec: EXTLINUX is now a separate package, syslinux-extlinux.

Changes in 3.20:

• EXTLINUX: New options --install (-i) and --update (-U), to make it clear if a boot loader should be installed or updated. For now, defaults to --install for compatibility; a future version will require one of these options.
• New library functions to load and place files in memory.
• mboot.c32 bug fixes.
• Remove 8 MB kernel size restriction.
• Add klibc target for building unix/syslinux and extlinux/extlinux with klcc (klibc-1.4.27 or later.)
• PXELINUX: Fail (and eventually reboot) if no configuration file was found.
• COM32 module by Erwan Velu to make decisions based on DMI info.
• Fix issue where going back and forth between menus a lot would cause a hang.
• ISOLINUX: Fix bug which made "cd boot sectors" not work.

Changes in 3.11:

• MEMDISK: Fix bug by which accessing the real floppy disk as B: in MS-DOS was broken.
• Simple menu system: allow tweaking of the screen layout.
• Simple menu system: better command-line editing, correctly handle command lines above 256 characters.
• PXELINUX: revert memory allocation change that caused problems on some network cards.
• MEMDISK: Try work around a bug on some BIOSes when no physical floppy disk is present in the system.
• Enable the 16550A FIFOs, if present, when doing serial console.
• New totaltimeout command establishes a timeout without regard for any user input.
• Simple menu system: timeout behaviour now more in line with user expectations.

Changes in 3.10:

• gcc 4.0.1 compilation fixes.
• Add support for querying the PCI BIOS in libcom32 (used by ethersel et al.)
• Fix PCI handing (ethersel etc) on several old chipsets (and VMWare.)
• Try to deal with systems with broken EBIOS.
• New API call to do "localboot".
• New API call to query features.
• New API call to run kernel image, a lower-level call than "run command". See comboot.doc.
• Fix for bug in EBIOS code discovered by Arwin Vosselman.
• NOESCAPE security fix.
• Comments are now recognized even without a space following #.
• Fix incorrect handling of mixes of entries with and without MENU PASSWD.
• The idle API call now harmlessly returns failure if it is a no-op. That way the caller can decide whether or not to bother invoking it again.
• Temporarily disable the idle API call on PXELINUX, due to some platforms on which the idle API call seems to hang; this problem has not yet been debugged.
• MEMDISK: the handling of DOSEMU-headered images was broken; fix it.
• EXTLINUX: symlinks are now supported.
• Simple menu system: N and P now work correctly as hotkeys.
• MEMDISK: more BIOS bug workarounds.

Changes in 3.09:

• gcc4 compilation fix.
• <BEL> (Ctrl-G) in message files now causes a beep.
• Reduce the command line to 511 characters; 1023 caused memory overflows.

Changes in 3.08:

• SYSLINUX: Fix performance regression (-s mode always enabled.)
• Add API function for idle loop.
• libutil: Add do_idle() function for idle loop, make get_key() use it.
• libutil: Add SHA-1 and base64 functions.
• Simple menu system: add password support.
• EXTLINUX: Sparse files now handled correctly.
• EXTLINUX: Large directories now handled correctly.
• ALL: At the prompt, Ctrl-X now forces text mode.
• Fix configuration file parsing error, that could cause hangs.
• Rewritten advanced menuing system from Murali Ganapathy.
• MEMDISK: New bigraw mode to work around certain broken BIOS flash programs.
• COM32 module to boot Multiboot systems, including Xen. See com32/modules/mboot.doc.
• Max command line changed to 1024 characters. Note that the kernel proper still can only handle 255 characters without patching, and COM16 binaries can only handle 125 characters.

Changes in 3.07:

• Fix chainloading (chain.c32).
• Fix zlib build problem.
• Use a private copy of <linux/ext2_fs.h>.

Changes in 3.06:

• Fix typo that caused the ramdisk to load in the wrong place.

Changes in 3.05:

• New API function "shuffle and boot"; allows COM32 modules to load or construct (almost) arbitrarily complex objects, e.g. a kernel and its initrd/initramfs in pieces, and have the API core reorganize memory for booting. (A library API for this function will be introduced in a later version.)
• The initrd= option now supports multiple filenames separated by commas. This is mostly useful for initramfs, which can be composed of multiple separate cpio or cpio.gz archives. (Note: all files except the last one are zero-padded to a 4K page boundary. This should not affect initramfs.)
• EXTLINUX: Fix API function 000Ah (get derivative-specific info).
• libcom32/ethersel: Support PCI Config Mechanism #2 on machines still infested with that hideous old hack.
• SYSLINUX: Fix directory-parsing bug.

Changes in 3.02:

• SYSLINUX: The unix installer now sets the MS-DOS attributes (hidden, system, readonly.)
• COM32 library: build the .lnx (test modules for running under Linux) as architecture native modules, in case i386 devel libraries aren't installed.
• EXTLINUX: Hack for systems which don't have BLKGETSIZE64 defined in the standard header files.
• Simple menu system: minor aestetic improvements, and try to work better over a serial console (speed, and readability on monochrome terminal emulators.)
• New CONSOLE directive to control output on the video console (useful for dealing with some broken serial-forwarding BIOSes.)
• New com32 module ethersel for searching for an Ethernet card and selecting the proper Etherboot binary.
• EXTLINUX: Allow the user to override the detected geometry. Add help.

Changes in 3.01:

• EXTLINUX, SYSLINUX: Fix compile errors on some systems.
• EXTLINUX: Default to zipdrive geometry if nothing else can be detected.

Changes in 3.00:

• SYSLINUX: Support FAT32 and EDD. As an unfortunate consequence, LDLINUX.SYS is no longer an ordinary file; it is block-mapped at install time, which means it can only be written using the syslinux installers.
• SYSLINUX: Reorganize the source code for the installers; each one of the installers (dos, win32, unix, mtools) is now built in its own subdirectory. In particular, mtools is the unprivileged installer which uses mtools; unix is the privileged installer which uses system calls.
• SYSLINUX: Completely rewritten DOS installer in C.
• ALL: LABEL statement information is now stored in a compressed format, which means that a lot more labels are permitted (500-1000 in a typical configuration, but depends on the complexity.)
• EXTLINUX: New derivative, which boots from an ext2/ext3 filesystem.
• SYSLINUX: The DOS and Win32 installers can now optionally write the boot sector to a file instead of the real boot sector. This is not supported in the Linux installers, however.
• ALL: New NOESCAPE command, disables the "hold down the Shift key to display the prompt" behaviour.
• New simple menu system, as an alternative to the advanced menu system already present. See README.menu for details.
• PXELINUX: Filenames can now be prefixed with an IP address or DNS name plus :: (e.g. 192.0.2.1::filename or server.domain.com::filename), which downloads a file from an alternate TFTP server, or just a :: (e.g. ::filename), which suppresses the common pathname prefix. See pxelinux.doc.
• SYSLINUX: Add an -m option to the DOS and Win32 installers to write an MBR and -a to mark the partition SYSLINUX is being installed on active.
• MEMDISK: Give a way to query the boot loader type while running MEMDISK; see memdisk/memdisk.doc and sample/mdiskchk.c.
• mkdiskimage: substantially improved mkdiskimage which, among other things, can now be used to initialize USB keys as zipdrives; see README.usbkey for more information.

Changes in 2.13:

• MEMDISK: Fix command-line parsing "brown paper bag" class bug.
• MEMDISK: Add "raw" mode to support the DOS boot disk from WinME/XP, which seems to deliberately crash the system when someone uses the "INT 15h mover" highmem API.
• Make "make install" do something sane for the com32 development environment.
• In the spec file, create a separate -devel RPM for the com32 development environment.

Changes in 2.12:

• Simple C library, based on klibc, for writing COM32 programs.
• Fix the handling of file length in loading of COM32 programs.
• MEMDISK: Work around a linker bug by rearranging the code to not use the linker for the 16-bit code.
• SYSLINUX: If we're building on a machine without a Win32 (mingw) compiler, just skip building syslinux.exe.
• ISOLINUX: Support non-mkisofs mastering programs, at least as long as the image is single-session. For best results, ISOLINUX should be the only boot loader installed.
• MEMDISK: Allow the user to specify that the simulated disk should be write-protected.

Changes in 2.11:

• ALL: Add an API call to get the configuration file name.
• SYSLINUX: Fix bug in 2.10 that prevented it from working correctly for a lot of people.
• SYSLINUX: In the installer, make mtools a bit less fussy.
• Make the menu system compile with newer gcc's.

Changes in 2.10:

• MEMDISK: Handle images compressed with zip as well as with gzip. Some Windows-based image tools apparently generate these kinds of images by default. Patch by Patrick LoPresti.
• Major menu improvement from Murali Ganapathy.
• ISOLINUX: Wonderfully sick and brilliant workaround for severe bugs in certain Award BIOSes; from Knut Petersen.
• SYSLINUX: Fix for the nomtools installed, from Frederic Pasteleurs.
• PXELINUX: Fix handling of IP numbers in the ranges 100-109 and 200-209.
• ALL: New option allowoptions (defaults to 1), which controls if options are allowed on the command line or not.
• SYSLINUX: Support building under klibc (see the klibc distribution for details.)

Changes in 2.09:

• SYSLINUX: Remove residual setuid crap from syslinux-nomtools.
• Handle video pages correctly when using the API functions.
• Handle compiling on an x86-64 platform correctly.
• Menu system from Murali Krishnan Ganapathy; see the menu directory for information.
• COMBOOT: Allow COMBOOT programs to change screen text mode.
• COMBOOT: Correct the documentation of how to detect SYSLINUX from COMBOOT!!!!
• COMBOOT: Fix "get key without echo" API function.
• SYSLINUX: Fix bug that affected the API open function.
• ALL: Improve the E820 memory parser, to work around some buggy BIOSes.

Changes in 2.08:

• Add new configuration command "ontimeout" to allow timeout to have a different action than just pressing Enter.
• Add new configuration command "onerror" to allow a custom command to be executed in case the kernel image is not found.
• Fix bugs in the COMBOOT/COM32 command-line parsing. APPEND now works with COMBOOT/COM32 images.
• PXELINUX: Poll for ARP requests while sitting at the prompt. This makes some boot servers a lot less unhappy.
• PXELINUX: Actually free sockets when we get a failure (including file not found.) This bug would cause us to run out of sockets and thus "go deaf" after a while.
• MEMDISK: Add an API to query for the existence of MEMDISK.
• SYSLINUX: Fix loading boot sectors (.bs/.bss) from floppy disk.
• .c32 is now one of the extensions searched for automatically.
• PXELINUX: RFBG.exe seems to randomly overwrite memory location 0x5700. Thus, don't use it!
• PXELINUX: Change pathname length max from 63 to 127; change max vkernels from 128 to 64.
• Support Ctrl-U -> kill entire command line input.
• The "samples" directory contains a (barely at all tested) chain loading example, chain.c32, which may be used to chainload local floppy disks and hard disks. Use with "chain fdN" or "chain hdN [partition]"; N = 0 for the first drive of each type.

Changes in 2.07:

• MEMDISK: Workaround for BIOSes which go into a snit when they get a RESET command for the floppy system when there is no floppy in the system.
• PXELINUX: Add ipappend 2, which passes the hardware address of the boot interface to the kernel as a command-line option.
• mkdiskimage: fix the generation of the end limit.
• PXELINUX: Fix multiple bugs in chainloading of other NBPs.
• MEMDISK: Fix bug that would occationally cause "ran out of input data" when using compressed disk images.
• SYSLINUX: Updates for the win32 installer (from Lars Munch.)
• PXELINUX: PXELINUX-specific options are now recognized both in a vendor-option-space (a.k.a. type 43 encapsulated) as well as in a site-option-space (unencapsulated.)
• COM32: Don't crash when DS != 0.
• COMBOOT/COM32: Make file reading work correctly. Thanks to Phung Chi Kien for submitting a test program.

Changes in 2.06:

• ALL: Fix problem that would occationally cause a boot failure, depending on the length of the kernel.
• ISOLINUX: Fix problem that would occationally cause a boot failure, depending on the length of directories.
• SYSLINUX: Win32 installer now flushes buffers.
• ppmtolss16: Be fully compliant with the PNM spec; actually process comments in the header and odd alignments of the various parameters, as well as "plain" (not raw) files and PBM and PGM files.
• PXELINUX: Lower the default MTU to 1472 in order to deal with systems with slightly nonstandard MTUs, and PXE stacks which don't defragment correctly. Unfortunately this is very hard to test dynamically.

Changes in 2.05:

• PXELINUX: Add a default query based on the hardware address of the boot device. This is in lower case hexadecimal form separated by dashes and including the hardware type, for example, the Ethernet (type 1) address 88:99:AA:BB:CC:DD would query the file pxelinux.cfg/01-88-99-aa-bb-cc-dd.
• PXELINUX: Fix bug involving non-IP-based config file names.
• SYSLINUX: New installer for WinNT-based systems, from Lars Munch.
• MEMDISK: Fix handling of memory region overlap when decompressing. Thanks to Mikhail Kupchik for identifying the problem.

Changes in 2.04:

• ALL: Reclaim even more low memory by observing that comboot_seg == real_mode_seg is perfectly fine, and by the fact that the 1000h segment managed to get unused in all derivatives...
• PXELINUX: Attempt to negotiate full Ethernet-sized blocks (1468 bytes) using the blksize option.
• SYSLINUX: Resurrect the old no-mtools version of the installer, although as a root-only tool. Some distributors have indicated that they need a small standalone installer.
• MEMDISK: Fix a memory offset computation error when installing compressed disks which generally would cause 1 MB of memory to be wasted.
• MEMDISK: Fix installing the E820 memory map. Calling INT 15h AX=0E820h with MEMDISK 2.03 loaded would give a completely corrupt memory map.
• SYSLINUX: Make libsyslinux a dynamic library, so that it can be updated separately from client programs. The whole idea, after all, is to enable alternate programs to become syslinux installers.

Changes in 2.03:

• Actually support comment lines in the configuration file.
• PXELINUX: Try to resolve some problems with stack switches.
• PXELINUX: Handle PXE stacks with broken routing. With these workarounds, the remote install PXE boot floppy (rbfg.exe) from Argon Technologies should work correctly.
• Fix problems with Perl scripts in UTF-8 locales.
• You probably need NASM 0.98.34 or later to compile this version. 0.98.36 is recommended.
• MEMDISK: Now supports gzip compressed images.

Changes in 2.02:

• SYSLINUX: Security flaws have been found in the SYSLINUX installer when running setuid root. Rewrite the SYSLINUX installer so it uses mtools instead. It therefore now requires mtools (specifically mcopy and mattrib) to exist on your system, but it will not require root privileges and SHOULD NOT be setuid.

Changes in 2.01:

• MEMDISK: Fix memory sizing bug when the ramdisk crosses the 16 MB boundary.
• MEMDISK: Add a pause option to stop immediately before booting, to read off the messages.
• MEMDISK: Support disk images with DOSEMU headers.
• Update the mkdiskimage script to handle newer mtools versions, and be able to generate disk images with DOSEMU headers (controlled by the -d option).
• Fix the COM32 sample program.
• PXELINUX, ISOLINUX: Fix some COMBOOT API calls.
• PXELINUX: Doc fix.
• Build SYSLINUX into a small library for encapsulation into other programs (however, please keep in mind this is a GPL'd library.)
• SYSLINUX: Make installer work with owner in /etc/fstab.
• SYSLINUX: Fix issue with working on nonpartitioned hard disk devices. This configuration is not recommended.

Changes in 2.00:

• ALL: Add support for "COM32" (32-bit COMBOOT) images.
• ALL: Add an API for COMBOOT/COM32 images. See comboot.doc for details. There is a C development environment for COM32 being created; it should be ready at some point in the future.
• Fix mbr.asm so that it actually works.
• SYSLINUX: The syslinux installer should now be safe to run setuid root.
• PXELINUX: Fix bug where PXELINUX would override random chunks of the UNDI code segment! Thanks to Kevin Tran for finding this bug.
• ISOLINUX: Fix a bug related to slashes in pathnames.
• ISOLINUX: Fix a bug in handling initrds over 128 MB.
• ALL: Make the <Ctrl-V> key print out the version; this is to help debugging.
• Add a small script, mkdiskimage, to create a DOS-formatted hard disk image using mtools. This may be useful in conjunction with MEMDISK.
• ISOLINUX: Search for a /boot/isolinux directory as well as /isolinux.
• ALL: Fix a bug related to very long configuration files.
• PXELINUX: Work around a NASM bug which would result in no delay before reset if an error occurs.

• ISOLINUX: Remove code no longer used which caused hangs on some Toshiba laptops.

• ALL: NASM 0.98.32 or later is now required to build SYSLINUX from sources.
• SYSLINUX: put back in the workaround for the BIOS floppy table. This seems to be a requirement for "extended" floppy formats to work correctly.
• SYSLINUX: No longer warn if one is trying to boot on a 286 or older. The above BIOS workaround no longer fits if the requirement to use only 8086-compatible code in the early boot is maintained. It made sense in 1994, but in 2002 a 286 or older is a museum object.
• SYSLINUX: Use a downright bizarre, stateful algorithm to try to guess the maximum transfer size. I am hoping this will cut down on the number of systems for which -s is required to work at any acceptable speed.
• ISOLINUX: Add a few more workarounds for various broken El Torito BIOSes.
• Make sure .depend files aren't accidentally packed...
• ALL: Fix bugs in the extension-detect code; this caused files like COMBOOT images and CD boot sectors to be mis-identified as Linux kernels and rejected.
• ALL: Fix the return from COMBOOT.
• ALL: Do some of the early groundwork for supporting DOS system calls in COMBOOT.
• Get rid of unnecessary neardirectives, making the code bigger.
• PXELINUX: Put the PXE stack back in the init state before invoking a chain-loaded NBP.
• PXELINUX: Actually found the combination of calls that allows some (most?) PXE 2+ stacks to be unloaded from memory properly.
• PXELINUX: Add keeppxe command-line option to disable the standard unloading of the PXE stack.

• SYSLINUX: fix bug that would cause valid kernel images to be labelled "invalid".

• Work on removing gratuitous differences between modules.
• Break up the source in common and module-specific files.
• PXELINUX: Allow chaining of other PXE NBPs.
• ISOLINUX: Allow loading "CD-ROM boot sectors".
• ALL: generalize the definition of a boot sector/NBP.

• PXELINUX, ISOLINUX: Fix bugs in the new core code.

• Fix a "brown paper bag" class bug in the new core code.

• Major code restructuring.
• Relax the conventional memory limits somewhat.
• MEMDISK: Set up the "version number string" pointer in the header correctly.
• SYSLINUX: Fix, again, "the bug that won't die": the use of the offset parameter with the SYSLINUX installer.
• SYSLINUX: Fix possible superblock corruption problem in the SYSLINUX installer.

• Handle bug in the location of initrd.

• MEMDISK: Make compile with newer versions of gcc.

• ISOLINUX: Support booting disk image files (to boot DOS or other non-Linux operating systems), if the BIOS works correctly; unfortunately many BIOSes apparently don't.
• Support Linux boot protocol version 2.03 (explicitly specify the initrd address limit.)
• Handle small "pseudo-kernels"; images that use the Linux kernel boot protocols but are less than 64K in size.
• MEMDISK: New subsystem; this is a driver which allows legacy OSes to boot using an in-memory simulated disk. See memdisk/memdisk.doc for more info.
• PXELINUX, ISOLINUX: Correctly handle files larger than 65535 blocks (32 MB for PXELINUX, 128 MB for ISOLINUX.)
• PXELINUX: Make a best-effort attempt at freeing all memory claimed. From the looks of it, it will fail on most PXE stacks.

• Limited support for hardware flow control when using a serial port console.
• Support specifying the serial port I/O address explicitly.
• Make DOS installer hopefully behave more nicely when used on recent Windows versions.
• Fix returning to text mode when a font has been specified.
• Attempt to detect missing serial port hardware and disable the serial port if there is nothing there.

• Make the ppmtolss16 program handle color conversion more correctly.
• Clean up make install target, honour INSTALLROOT if it exists.
• SYSLINUX: Fix stack-smash bug identified by Steffen Winterfeldt.
• Hopefully fix return-to-text-mode on some graphics cards.
• ISOLINUX: Bug workaround for Award BIOS 4.51, and perhaps other buggy BIOSes as well.

• PXELINUX: Allow the DHCP server to override the configuration file name and pathname prefix, using "site-specific" DHCP options.
• PXELINUX: Documentation fixes.
• PXELINUX: Fix the IPAPPEND option; the last two values were reversed vs. what the kernel expected.
• Introduce a way to return to text mode once we are already in graphics mode. This may be useful for F-key help screens.
• Fix several bugs in the way return to text mode was handled.

• ISOLINUX: Support full pathname searches. Max length for a pathname is 255 characters. As a result, only 64 LABEL statements are supported in ISOLINUX.
• PXELINUX: Max filename length extended to 63 characters.

• Add support for graphical splash screens.
• Add mode control characters, which allows you to control message display output depending on output mode (text, graphics, or serial port.)
• ISOLINUX: New program, which boots Linux from a CD-ROM without using floppy emulation mode. See isolinux.doc for more details.
• PXELINUX: Don't search for boot sector file types, since they don't work anyway.
• SYSLINUX: Document the LOCK command for Win9x, and the error dialog box for WinNT/2K.

• PXELINUX: Fix code for finding !PXE from PXENV+. This was due to a spec bug; match the most recent spec since that seems to be what implementations actually do.
• SYSLINUX: Add some smarts to the boot sector, which hopefully should reduce the number of systems which require stupid mode (syslinux -s).
• PXELINUX: Document further some of the pathologies with old PXE stacks.
• When specifying a DEFAULT command line, no longer automatically append auto. See the DEFAULT command in syslinux.doc for more information.
• PXELINUX: Clean up the allocation of local socket numbers.

• PXELINUX: Rename pxelinux.bin to pxelinux.0, to match what most PXE servers seem to expect.
• PXELINUX: Update the DHCP/boot server setup documentation.
• PXELINUX: Support new LOCALBOOT option for LABEL sections.
• PXELINUX: More robust parsing of DHCP/boot server packets.
• PXELINUX: Include a small utility program gethostip to compute hexadecimal IP addresses.

• PXELINUX: Fix bugs introduced by new A20 code. (SYSLINUX has also been changed for code consistency reasons, but I'm pretty sure the changes are don't care on SYSLINUX.)
• Documentation updates.
• PXELINUX: Add IPAPPEND option to generate an ip= option to the kernel.

• PXELINUX: Not all PXE stacks fill in the IP address for a type 3 cached info query. Use a type 2 cached info query for this information (only.)
• Yet another attempt at A20 coding. Now support BIOS call 15:2401 as well, and handle machines which always have A20 on separately.
• Support memory detection using INT 15h, AX=0E820h. BIOS manufacturers have apparently gotten sloppy about keeping INT 15h, AX=0E801h working properly.
• Don't issue onto the serial port when we're doing screen wraparound.

• Yet another A20-code update. It seems some "legacy-free" machines and embedded gear simply don't have a KBC to talk to, and that waiting for one will wait forever. Sigh.

• SYSLINUX: Implement a hack for BIOS drivers which hog significant chunks of low memory during boot. (Note: PXELINUX already had this modification. SYSLINUX does still require that the low 512K is available; PXELINUX requires 384K. Machines with a physical memory hole in the low 640K cannot boot Linux no matter what.) Depending what the reason is for the memory hole, a new kernel (2.4.0-test3-pre3 or later) may be required.
• SYSLINUX: Default installer binary now compiled against glibc 2.1. If this is inappropriate for your system and you still want to use the offical version of SYSLINUX, please follow the instructions in distrib.doc to rebuild the installer.
• SYSLINUX: Linux installer program now supports -o <offset> option which does a loopback mount with the -o loop,offset=<> option. Useful to run SYSLINUX on an individual partition of a whole-harddisk image.
• Include the source code to a Master Boot Record (MBR) functionally equivalent to the one installed DOS except it includes EBIOS support, and should be resistant to geometry changes. The MBR code is public domain.
• PXELINUX: Fix "double p" bug: if the tftp prefix was null, all filenames would get a "p" preprended, e.g. "ppxelinux.cfg" and "pvmlinux".

• PXELINUX: Workaround for PXE ROMs based on the Intel PXE PDK 3.0 build 071 and earlier: missing !PXE structure pointer.
• PXELINUX: Handle larger BOOTP/DHCP packages.
• PXELINUX: The command line passing was broken; fix.
• PXELINUX: Make COMBOOT images work.
• PXELINUX: Documentation on how to make booting work using the PDK 3.0-derived clients, which aren't so generous as to allow booting with only PXEClient specified.

• PXELINUX: RFC 1123 states that a TFTP implementation MUST use adaptive timeout, "at least an exponential backoff of retransmission timeout is necessary." Implement a very simple exponential backoff for retransmits.
• PXELINUX: Updated documentation, including pointer to new TFTP server.
• PXELINUX: When sending ERROR due to bad OACK, use the proper destination port number (why are TFTP port numbers so odd?)
• PXELINUX: If the boot dies in the middle somewhere, eventually give up and reset the machine (unattended operation.)

• New program PXELINUX to do network booting using a PXE-compliant (Pre-Execution Environment) network booting PROM. See pxelinux.doc for details.

• Serial console support. See syslinux.doc for details.

• Change HIGHMEM_MAX to 38000000h to (hopefully) avoid the kernel stepping on it; 3f000000h was apparently a higher limit than the kernel used!

• Add sys2ansi.pl script to display the contents of a colorized SYSLINUX file.
• Changed the io_delay once again, after a report that the old delay port causes hangs on some systems.

• Frob the "fast A20 gate" port as well as the keyboard controller; will this help systems with problems?
• Be even more paranoid about A20, unfortunately even this seems to be not paranoid enough... what I don't understand is that if there is hardware out there this broken, how can it run Linux at all? Report an error message rather than hang forever if A20 is stuck.
• Include some intermediate files in the distribution, plus provide a "make installer" target for distributors to relink the install programs only. I would prefer the syslinux boot loader proper to be "binary clean" for debuggablity -- use "make clean ; make installer" to rebuild the installers only.

• Don't get confused by directories, volume labels, or VFAT long names.
• Use INT 15h, AX=0E801h to query memory size before trying INT 15h, AH=88h. This not only provides more headroom between the kernel and the initrd on large-memory machines, but it appears some recent BIOSes actually have started returning garbage for the AH=88h (older) call.
• Trust high memory beyond the 15 MB mark if the user has specified it, or if obtained with INT 15h, AH=0E801h (with no memory holes above 1 MB.)

• Increase A20M delay and put in a test to avoid problems on certain IBM Thinkpads (thanks to Donnie Barnes of RedHat for vital info on this one.)
• Support COMBOOT style boot command images.
• Support chain loading (foreign operating systems, e.g. DOS).
• Include a new copybs DOS utility to copy a boot sector to a file (under Linux, use dd.)
• Fix the DOS installer to work for disks over 32 MB.
• SYSLINUX should now handle disks with more than 65536 tracks.

• Fix a bug that caused LABEL statements in syslinux.cfg to not be handled properly.
• Updated the documentation. Among other things, we now allow up to 128 "label" statements.

• Fix for booting old (pre-initrd) kernels.
• It seems at least some versions of OS/2 doesn't set up all the fields in the superblock correctly. Account for that.
• Fix bug that caused boot failure when using the mem= option.

• Loading from partitions now should work properly. (Actually tested, this time. You should even be able to dd a floppy to a partition and boot from it.)
• Removed large workaround code for an alleged ancient BIOS bug I have never actually seen. The -s option should work on those machines, anyway.
• Support for simple keyboard remappings, same as used by LILO (once again to support localization.) The program keytab-lilo.pl from the LILO distribution included to generate such maps.
• Added a "safe, slow and stupid" (-s) option to the installers. This option will lobotomize the boot sector to hopefully work on even very buggy BIOSes.

• Ability to load a VGA font on bootup (for localized Linux distributions.)

• Bug fix in the Linux installer.
• Added a workaround for a bug in certain AMI/Intel BIOSes when booting from CD-ROM.
• Documentation changes.

• FAT16 filesystems are now supported.

• Now compiles under Linux, using NASM, rather than using Turbo Assembler under DOS. See http://www.cryogen.com/Nasm for information about NASM.
• Linux-hosted SYSLINUX installer, as well as a rewritten DOS installer (now is written in assembler, so we don't need Turbo C.)

• Added support for loading bzImage and initrd loading, and made SYSLINUX new-setup-code aware (SYSLINUX 1.30 id=0x31).
• Added LILO-style kernel labels; see the LABEL and IMPLICIT keywords in README file.
• Added support for colorization of intro and help screens.
• The vga= option is now handled correctly.
• Massive rewrite of large chunks of the code in order to support the first two new features.

• Added simple online help at the boot: prompt.
• Removed 2880K image as I no longer have access to such a floppy drive. (Donations accepted!!)
• Decided to distribute the source in a subdirectory rather than in a nested zipfile.

• Removed a sanity check which would cause booting to fail on Phoenix BIOS version 4.03. Apparently this BIOS is buggy.

• Added configuration file SYSLINUX.CFG. This file contains all configurable options, and can be edited from any OS which can access an MS-DOS filesystem; there is no longer a need to run SYSLINUX.EXE except to write the boot sector.
• Default command line now given by DEFAULT line in config file.
• LINUXMSG.TXT and BOOTMSG.TXT hard-coded file names replaced by DISPLAY and PROMPT lines in config file.
• LILO-style option appending now supported (APPEND line in config file).
• Prompt timeout is now supported (TIMEOUT line in config file). The timeout is cancelled when anything is typed on the command line.
• Pressing <ESC> or <Ctrl-C> at the Loading... stage now aborts the kernel loading in progress and returns the user to the boot: prompt.
• The installer now automatically sets the READONLY flag on LDLINUX.SYS.
• Added 2880K disk image.

• Fixed bug that would prevent booting from double-density floppies and other DOS filesystems with multiple sectors per cluster.
• Added 720K disk image.
• Changed default kernel name on disk images to LINUX.

• Fixed bug that would garble the command line on recent kernels with more than 4 sectors of setup code (this wasn't really a bug; rather, a kernel change broke the code. Unfortunately the Linux boot interface is still sorely undocumented).
• Added BOOTMSG.TXT file support (message file which does not force display of the boot prompt).

• Fixed bug on some (most?) 386 BIOSes would require two boot attempts.