mbldr (Master Boot LoaDeR)

Table of contents:

1. News
2. Summary
   • About
   • History
   • Project name
   • Project goals
   • What probably never will be a goal
3. License
4. Documentation
   • Requirements
   • Installation, uninstallation and configuration
   • Frequently asked questions (FAQ)
   • Useful hints and advices
   • Important notices and limitations
   • Known issues
   • Troubleshooting
5. Screenshots
6. Features
7. Download
8. ToDo
9. Help needed
10. Translation status
11. Building instructions
    • Building under Linux and BSD-flavours
    • Building under DOS and old Windows
    • Building under NT-family of Windows
12. Contacts
13. Links

News

December 12, 2008
mbldr 1.46 has been released. New chainload feature (refer to FAQ section, question #13), fix of hanging with timer interrupt, Czech translation, "restore from backup" changes.

May 30, 2008
mbldr 1.45 has been released. Boot-timer fix, French translation, partitions hiding/not hiding, few other improvements.

December 19, 2007
Mbldr sources are now available in Subversion repository on Sourceforge. Use "svn co https://mbldr.svn.sourceforge.net/svnroot/mbldr mbldr" command to get the source tree. Initial version in Subversion corresponds to mbldr-1.44, I have not added earlier versions.

November 29, 2007
I posted new open position to "Help wanted" section on the sf.net web-site. It asks for new translations.

November 23, 2007
mbldr version 1.44 has been released. It introduces multilanguage interface (only Russian translation is available now).

June 6, 2007
mbldr version 1.43 has been released. It introduces new GUI configuration program.

January 11, 2007
mbldr version 1.42 has been released (changes are only in Windows version of installation program).

November 29, 2006
mbldr version 1.41 has been released. It introduces the support of Microsoft Windows Vista.

November 15, 2006
mbldr version 1.40 has been released. It contains no code developed by Thomas Wolfram anymore, so the project is now totally covered with BSD license. The only significant difference is that I have removed the line "All advertising materials mentioning features or use of this software must display the following acknowledgement: This product includes software developed by Thomas Wolfram."

October 31, 2006
mbldr version 1.39 has been released

August 18, 2006
mbldr version 1.38 has been released

June 13, 2006
mbldr version 1.37 has been released

March 10, 2006
mbldr version 1.36 has been released

Summary

About

History

Project name

Hi,

I'm sorry. I do not allow to use the name OS-BS for
an open source project or any other purpose. Also
I do not allow redistribution of my source code under
any other copyright or license terms than my own.

It is not possible for me.

The software OS-BS has become a commercial product since
1997 and is sold in several versions in Germany, France,
Spain and elsewhere. It has evolved much since the
early 1.x and 2.x versions.
The rights are hold by a large software publishing house
and I continue development of the product for them.

regards,
Thomas Wolfram
 

> -----Original Message-----
> From: Arnold Shade
> Sent: Tuesday, March 07, 2006 4:45 PM
> To: Thomas Wolfram
> Subject: OS-BS
> 
> Hello,
> 
> My name is Arnold Shade. I have found your nice program called OS-BS in /tools directory
> on one of FreeBSD distribution disks. It's really nice, but since it seems you are not
> supporting it now (2.0b8 release was done in October 1993), I would like to continue
> open-source development of this program.
> [ ... skip ... ]
> As a starting point of my development I have decided to use 1.35 release of OS-BS
> because it fits into 1 sector. Version 2.0 uses more than 1 sector what is not my goal.
> 
> As far as I understand you tried to evolve OS-BS to commercially
> available software available at http://www.bootmanager.com/
> 
> Thus, my question is: Do you allow the existence of successor of OS-BS? May I be current
> maintainer? May I use BSD license for it? May I create an appropriate project of
> sourceforge and publish all the details there? I promise to leave current name without
> modifications (OS-BS) and write your name wherever acceptable (README files, about boxes,
> web-site, etc.) However your signature ("wolfRAM") will be lost in MBR and I will break
> the compatibility with older versions (location of some data structures in MBR will be
> changed) because I'm optimizing the code much.
> 
> Thank you in advance.
> 
> Best regards,
> Arnold Shade
     

Project goals

• To maintain a boot loader which fits into master boot record (only 446 bytes, some place is occupied by partition table) of a hard disk. There are lot of boot managers occupying almost whole track #0 of cylinder #0. I don't want to compete with them. The unused sectors on track #0 are also often used by recovery software, so the chance to break something is relatively high.
• To allow a user to choose which operating system to boot with a simple textual interface (no graphics, icons, mouse, etc.) with timeout and default boot
• To support booting of operating systems which are located beyond 1024 cylinder boundary
• To support as many operating systems as possible (however I'm focused on modern ones)
• To support partitions hiding according to rules used on OS/2 boot manager (applied to different FAT and NTFS), so partitions are marked correctly from the point of view of PowerQuest Partition Magic (commercial software managing partitions).
• Booting from any primary partitions or logical disks on extended partition

What probably never will be a goal

• no special code to support booting from CD/floppy: Floppies are obsolete, booting from CD could be activated by pressing Esc (for Award BIOS) or F11 (for AMI BIOS) at boot time. However modern BIOSes allow booting from CD after calling interrupt 18h (what corresponds to "Skip boot" menu item)
• no rich GUI interface with icons and mouse support for the boot loader
• no boot-time password protection
• no boot manager configuration directly from boot menu (like autosearch of partitions in Smart boot manager)
• no binding to operating system types, their boot loaders, filesystem formats and other implementation-specific details
• no support for non-x86 platforms

License

Copyright (c) 2006-2008, Arnold Shade
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.
* Neither the name of Arnold Shade nor the names of contributors may be used
  to endorse or promote products derived from this software without specific
  prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     

Every new piece of code (patches, fixes, improvements, etc.) submitted for inclusion into mbldr should satisfy the license shown above.

Documentation

Requirements

1. So-called IBM PC-compatible computer with Intel 386 architecture CPU is required. It will not run on Sun Sparc or PowerPC-based Macintosh.
2. Relatively modern BIOS that allows to use new functions of interrupt 13h for loading/saving sectors (in order to support booting from >1024cyl). Mbldr is incompatible with older BIOSes (even when booting operating systems below 1024cyl)
3. The CLI version of installation/configuration program could be compiled and run under MS-DOS/FreeDOS, Windows 98/ME, Windows 2000/XP/Vista, Linux and BSD. GUI version supports Windows 2000/XP/Vista, Linux and BSD (DOS and old Windows-family are not supported), it requires wxWidgets development toolkit for building. DOS version requires DPMI interface (it also works under Windows 98 or ME in DOS-emulation mode). DOS version does not work under NT-family of Windows in DOS emulation mode, you need to use special version for Windows 2000/XP/Vista.

Installation, uninstallation and configuration

1. Download .zip archive with a binary corresponding to the latest release of mbldr
2. Unzip the contents of the archive to some directory on a hard drive. The directory should be located on a partition accessible by DOS, i.e. it should be either FAT or FAT32. You may also copy it on a floppy or a CD.
3. Download and unzip the contents of DPMI server. If you are using CWS DPMI, make sure that CWS executables are located either in the same directory as mbldr executable or in a directory listed in PATH environment variable (under Windows 98/ME you don't need DPMI engine)
4. If you are running Windows NT-based operating system (2000/XP/Vista) reboot from DOS-bootable floppy. El-torito CD could be used as well. Under Windows 98/ME you may use DOS-emulation box without rebooting into DOS. (of course you do not need this step if you are using Windows 2000/XP/Vista version of installation program)
5. Run "mbldr.exe -h" to get command line help (in Windows 2000/XP/Vista or Linux/BSD name of the command-line executable is mbldrcli)
6. Run "mbldr.exe" (mbldr.com for very old versions) to enter interactive configuration mode (you may need to specify device name to manage under Linux or BSD with the help of -d command-line switch, however autodetection is supposed to be working properly)
7. The navigation through menus is done with command-like interface. You should read a list of bullets, make a choice and then type the appropriate symbol (usually a digit or a lower-case letter, but could also require typing numbers and labels) and then press <Enter> to confirm.
8. Use special boot menu item "Skip boot" if you want to instruct BIOS to try another boot device. Mbldr calls int 18h what usually leads either to network boot or CD-ROM boot (depending on a boot sequence configured in BIOS).
9. Use special boot menu item "Try next hard disk" if you want to load MBR from a next hard disk (increasing BIOS device number: the first is 80h, then 81h, etc.). Please note that this option is dangerous and may lead to data corruption. If configured improperly your MBR may be mistakenly overwritten by other boot managers. Use with caution and thoroughly read the following warning: New master boot loader gets a number of drive being used as a parameter. Theoretically this scheme should work fine assuming that all boot loaders respect this input parameter. Unfortunately several boot loaders ignore it assuming that the drive number used to boot is always 0x80 (what is incorrect according to EDD3 specification). It may lead to impossibility to boot for so called "passive" master boot loaders (that just try to boot not updating MBR each time). But even worse for so called "active" master boot loaders (that modify MBR each time you boot) you may overwrite MBR on the wrong disk. Please note that "Next HDD" feature is not the same as the one provided by BIOS (boot from either of installed hard disks). BIOS does the renumbering of hard drives making bootable disk always 0x80, while mbldr does not. Use this feature at your own risk! It is dangerous and may lead to data loss if you have master boot loaders others than mbldr with version 1.37 or above! However I have tried following combinations successfully: mbldr+mbldr, mbldr+LILO, mbldr+GRUB, mbldr+standard MBR from DOS/Windows. Any others probably don't work, in particular mbldr136 and os-bs. Use this feature at your own risk, it's DANGEROUS!
10. You always may use 'q' to immediately quit from a program without saving any changes. Also try Ctrl-C if something goes wrong.
11. Before making any changes on your hard disk the program will ask for a confirmation
12. Always do a backup of the old MBR. Better to store this file somewhere on a bootable floppy or El-torito CD together with appropriate version of mbldr installer. Please note that uninstallation of mbldr is impossible if you have not saved the backup copy of MBR first.
13. The length of particular label for a bootable partition is not limited. Only total number of characters used for boot menu makes sense. You will get a warning when you exceed it.
14. Don't use non-standard native charsets when typing labels. Even if they are visible at the time of configuration these symbols are not yet available at boot time. Instead you will see unreadable sequence of pseudographic characters garbling the display.
15. Please note that mbldr overwrites MBR not only at the time of installation but as well each time you boot (setting "active" flag for current partition and hiding inactive FAT/NTFS partitions). You have to switch off MBR boot-virus protection in BIOS in order to boot correctly
16. Mbldr installation program does not modify the partition table in MBR (except restoration from backup) thus it is not mandatory to reboot after you have installed mbldr
17. When restoring from a backup mbldr recognizes if the partition table has been changed. It could be a moved "active" flag but also a real different partition table (you are informed about that). Here you have two options: full overwriting of existing MBR with a backup file (could be dangerous since an out-of-date table may be restored, but useful if your master boot sector is destroyed) or restoring only the master boot loader program keeping partition table untouched.

For Linux or BSD you deal with tar.bz2 archive, you need to compile the program using Makefile.unix and you need to be root in order to run the installation (this is because you are modifying disk directly using something like /dev/hda). For Windows and Linux/BSD all DPMI-related stuff is not needed, file-system type restrictions are also not applied. Please take in account that you have to properly reconfigure your main boot-loader (like LILO) to avoid conflicts with mbldr and allow them to coexist.

To avoid an inconsistent state of MBR contents it is necessary to reconfigure mbldr each time you move any of the bootable partitions (for example with a help of PartitionMagic). Resizing operation (without movement) of bootable partitions does not affect mbldr internal tables. Movement, deletion etc. of non-bootable partitions also does not affect the configuration of mbldr.

Note: the active id does not have its usual meaning to mbldr. "Active" is only a flag in the partition table that may be analyzed by respective operating system. Mbldr sets it to appropriate primary partition marking the OS as "active" at boot time. Logical drives are never marked as "active". Hiding of logical drives is also not performed.

"fdisk /mbr" doesn't affect the partition table. It puts only an ordinary master boot program back. This is another way to uninstall mbldr. But please note that there are some differences in the master boot loaders placed by different operating systems, so be careful. For example, if you call "fdisk /mbr" from MS-DOS 7.1 (part of Windows 98/ME) MBR is initialized with a boot code that is unable to boot operating system above 1024cyl.

If you are unfamiliar with mbldr yet and don't like command line, it is suggested to begin with GUI version (mbldrgui.exe under Windows 2000/XP/Vista), take a look on screenshots section.

Frequently asked questions (FAQ)

Q2: I have set up mbldr and then booted my Windows XP. But it accidentally shown me a dialog with something like that: "New hardware has been found. Would you like to reboot?" What is this all about?
A2: At the time of Windows installation MBR is updated with the boot loader and 4 bytes presenting a DiskSignature (or so-called NT Driver Serial Number) of a hard drive which is issued by Windows installer. Installation of mbldr overwrites these bytes. Most probably it leads Windows to redetect and possibly enumerate partitions on this HDD what causes updating of internal hardware database. As a result of that you see this dialog. I believe it could be safely ignored (just press "No" there) since no actual changes have happened in system's hardware. This applies to mbldr 1.40 and below, all newer versions should keep DiskSignature untouched.

Q3: When I run mbldr.exe I see "Load error: no DPMI - get csdpmi*b.zip", what should I do?
A3: It seems you are running mbldr.exe in a pure DOS environment. You need to get DPMS extender in order to run mbldr.exe. You may use free CWS DPMI server (redistributable under the GPL). Release 5 of CWS DPMI could be found at ftp.delorie.com or here is a local copy. Unpack binaries to the same directory where mbldr.exe is stored and run it once again.

Q4: When I run mbldr.exe I see "Warning: cannot open swap file c:\cwsdpmi.swp" but then the execution continues. Is there something wrong with it?
A4: You may safely ignore this warning produced by CWS DPMI server. Usually it happens when no disk C: is found in a system (for instance all FAT/FAT32 drives are hidden or disk is not yet partitioned). Since mbldr does not require too much memory swap is not needed in general.

Q5: When I try to boot one of my operating systems the boot menu just redraws itself ignoring boot attempt. What is going wrong and how to boot my OS?
A5: There are at least two reasons that may cause this issue. One of them is that you have moved (or deleted and then created in another place) the partition with the operating system you want to boot. In this case you have to reconfigure mbldr (delete the entry marked as "[!!!BROKEN!!!]" and then add it once again). The another reason of this problem maybe in the limitation of BIOS. For example some motherboards don't detect hard disks bigger than 128Gb. This limitation is also applied to BIOS EDD3 calls (enhanced int 13h) therefore you cannot load boot record of a partition above this boundary. Anyway the common explanation of boot menu reappearance is either an error of BR sector reading or an absence of 0x55AA magic number at the end of sector being read.

Q6: Compilation breaks with "error: argument to ORG should be numeric" message in mbldr.err. What am I doing wrong?
A6: Till mbldr 1.44 the version of nasm required for building was greater or equal to 0.98.36. Release .35 which is often shipped in many popular (but rather old) distributions could not be used. Please note that starting on version 1.45 of mbldr nasm 2.x. is required.

Q7: When trying to update the MBR contents on /dev/ad0 under BSD I get "Operation not permitted" error. How to overcome this?
A7: This protection of BSD is active because hard disk is available for writing at the moment. Try to issue a command "sysctl kern.geom.debugflags=16" to temporarily disable it. Update your MBR and then return this value back to 0.

Q8: I am using two items in my boot menu: "1. Windows XP" and "2. Skip boot". I have configured the default menu item to be the last OS I booted to. So I expect "Skip boot" should be the default one after I tried to use it once. But it seems that mbldr always boots Windows XP. Why?
A8: "Skip boot" and "Next hard disk" are special boot menu items that are associated neither with particular partition nor with an operating system. They are not remembered as default boot menu items unlike usual partitions. However you may still mark them as default ones manually.

Q9: I had 2 hard disks in my PC, both have Windows XP installed, I used dual boot with the help of NTLDR. When I switched off first HDD, second one did not boot alone. I installed mbldr onto a second hard disk but when I choose the item in boot menu system just hangs. How to boot second Windows without my first hard disk?
A9: This is not a problem of mbldr, you need to reconfigure Windows boot loader in order to boot properly. When you installed second Windows on the old PC configuration (with two hard disks), Windows installer has configured the existing boot loader on the first HDD. Both MBR and boot record on the second HDD was left intact. So, after you removed the first HDD system was unable to boot and it is expected. In addition to installation of mbldr on the second hard disk you should repair Windows loader in first sector of a bootable partition. It could be done via system recovery console. Please refer to How to use fixboot, Why Windows XP does not boot (Problem #6) and Recovery console overview

Q10: I have one hard disk with 3 primary partition: one for Windows, one for my personal data and one for a backup image of Windows. I used mbldr so I can be able to boot Windows or restore the image. The problem is that when I use mbldr partitions 2 and 3 become hidden including partition 2 which contains my personal data.
A10: You are right, mbldr can hide all other primary FAT/NTFS partitions when booting either of configured operating systems. So, in your case partitions 2 and 3 are hidden and it is expected behavior. You can disable partitions hiding if you want to (this is a global setting, not applicable for individual partitions). You may also convert your primary partition #2 into logical disk on extended partition - this will let you to aviod hiding of this particular partition (please note that conversion operation may cause data loss). Also please note that if you are using Windows 2000/XP (not 98/ME) as your main operating system, you may ask it to access hidden primary partitions in the same manner as for visible ones. Go to Start->Settings->Control_Panel->Administrative_Tools->Computer_Management. There you should choose Disk_Management in the Storage tree branch and use Change_Drive_Letter_and_Path item in context menu on a desired partition. Unfortunately Windows 98/ME do not support this.

Q11: I have plugged second hard disk to my home PC. My main HDD has mbldr installed, but second one also contains Windows operating system (no mbldr there). I wanted to reconfigure mbldr in a way to add one more option for booting from another HDD but this feature does not function properly. Windows on second HDD is not booted at all while all others remain ok. How can I boot an operating system from second hard disk?
A11: This is true, sometimes "Try to boot from next hard disk" option does not result in normal boot of operating systems on any HDD except the first one. This is not because of improper functioning of the mbldr code in MBR, but mainly because of bad implementation of OS-specific boot-loaders (like ntldr). The workaround in this case could be the following: instead of using "Try to boot from next hard disk" try "Skip boot attempt and try another device" menu option. In this case you need of course to adjust the settings in your BIOS accordingly - your first HDD should be first boot-device, your second HDD should be the second (floppies, network boot and CD-ROM boot should be below hard disks). You probably also need to check another BIOS option called like "Boot other device" or "Try other boot devices" to disable the limitation of booting only from the first configured device (first HDD in our scenario) - it is usually located near the definition of boot devices priority.

Q12: What is the difference between system and user timers in the section of timed boot configuration?
A12: The main and most reliable way to configure timed boot is to use so-called "user timer" which corresponds to interrupt 1Ch. But unfortunately some buggy BIOSes (mainly on modern laptops) do not call this interrupt causing timer in mbldr to stand in idle. If you experience problems with timed boot while all other methods work fine (immediate boot, boot by request typing a key, etc.) try to change the timer from "user" to "system" in mbldr configuration.

Q13: How can I use chainload feature?
A13: This feature is inspired by forum thread about TrueCrypt, where it was suggested to allow mbldr to coexist with other software which occupies MBR. So, typical scenario includes installation mbldr after the software like TrueCrypt, saving the contents of MBR to another sector (safest way is to use one of empty sectors from first track on first cylinder). As mbldr allows to backup and restore MBR to/from any sector or a file you are free to manage the contents of any sector you need without other tools. So, the example with TrueCrypt is: install TrueCrypt in full-disk encryption mode (this affects MBR), boot Windows, run mbldr installation/configuration tool, save current contents of MBR (including partition table of course) to one of the empty sectors on first track (mbldr provides you with a list of empty sectors), add chainload entry to the list of bootable entries. You may need to disable partitions hiding and disable marking bootable primary partition as active to let TrueCrypt copy of MBR think it resides in MBR (otherwise it informs you about differences in partition tables). Please note that every time you move, create, delete or resize partition you need to resync partition table between actual MBR and chainloaded copy.

Useful hints and advices

• Disable all MS-DOS disk caching programs before installing/configuring master boot sector with mbldr.
• Disable BIOS write-protection on boot sector and master boot sector. It may block mbldr from updating "active" flag and hiding unused partitions. Remember - the master boot sector is written back every time you boot.
• Always keep bootable floppy or CD with a backup of MBR. If for some reasons the MBR loader or (what is even worse) partition table is broken, you may restore it with the help of mbldr.
• All known versions of fdisk program running under MS-DOS (including MS-DOS 7.1 with fdisk taken from Windows ME) do not support booting of an operating system which resides above 1024 cylinder. Thus "fdisk /mbr" may not help you in some cases. At the same time MBR boot loader included into Windows XP supports that.
• When using Linux with LILO it is reasonable to install LILO into boot record of a chosen partition, not MBR. Of course if you want to use mbldr ;-)
• Installation of all known Windows operating systems overwrites MBR. You have to reinstall mbldr after you install any Windows on any partition. Since boot record of a target partition is also updated by Windows installation routine it is safe to overwrite MBR contents with mbldr.
• Mbldr behaves correctly in a configuration with two HDDs or even more. The configuration program allows you to choose target hard disk, so you may install mbldr on even all of them.
• Since mbldr is able to boot operating systems from logical disks you may configure MS-DOS and Windows to work in that way. Install Windows to primary partition and then convert it to logical drive (for example using Partition Magic by PowerQuest). It was tested for Windows 98, ME and XP but others should work fine as well.
• When installing mbldr you may use empty boot menu text and very low timeout value (let's say 1 second). Default operating system will be booted almost immediately but those people who know this trick may press "magic" button to modify the boot behavior. For others it would seem like no mbldr is installed at all (invisible mode).
• You may use custom menu to hide particular operating systems in a boot menu. Let's say visible choices are "1. MS-DOS" and "2. Windows XP" but the remaining operating systems will be wiped from the boot menu text manually. So you always may press "3" to boot for example FreeBSD.
• Despite the fact that mbldr does not support booting from CD-ROM directly, you always may try to configure the bootable sequence in BIOS like "try HDD0 and then try CD-ROM if failed". In this configuration you may use boot menu item labeled "Skip hard disk boot" to boot from a CD-ROM.
• Use <Enter> key to immediately boot default partition instead of pressing appropriate numbers like '1' or '2'.
• mbldr may even be useful for servers that do not need multi-boot into different operating systems. Imagine the following situation: you have a standalone server protected by a universal power-supply. After a long electricity outage the capacity of UPS battery has been depleted, server detected that and went to shutdown until the power is off completely. Then external voltage has been recovered just to be switched off again after few minutes. During this period our server becomes operational, but the capacity of a UPS battery was not restored yet. Thus after second outage the server will not have enough time to shutdown - weak battery will not handle that. Bringing mbldr into the picture we may initiate a delay before server begins to boot (let's say 10 minutes). During this time battery will be recharged and it is safe for server to boot. Otherwise the power will be switched off at the time of mbldr waiting what is not dangerous for data.
• If you run mbldr configuration tools (CLI or GUI) under Microsoft Windows Vista please note that by default all programs have reduced abilities even if you are logged under a user with an administrator priviledges. So if you just launch mbldr configuration utility with a double-click it will be unable to detect your local hard disks (mbldrcli will immediately exist, mbldrgui will have left part of "device choice" dialog disabled). You need to right-click on a mbldrcli/mbldrgui executable and choose "Run as administrator" option from popup context-menu.
• Please note that you can install mbldr neither on CD-ROM/RW nor on DVD-ROM/RW drives, they have completely different structure of data-storage and use another boot methods. If you want to make compact disks bootable you may find ISOLINUX project interesting.
• While compact disks can not be used with mbldr, USB flash drives can be. Usually (if formatted from Windows) USB flash drives have an MBR and one primary partition occupying whole flash-card (which can be used for a bootable operating system).
• You can not install mbldr onto floppy disks as they do not have MBR.
• If you use chainload feature it is recommended to keep partition tables (in the main MBR and secondary chainloaded copy of MBR) in sync. So, every time you create, delete, move or resize partitions you need to copy new partition table to chainloaded copy of MBR.

Important notices and limitations

• mbldr supports so-called DOS-style partition tables (4 primary partitions or 3 primary + 1 extended with 1 logical disk per extended partition). non-DOS partition tables are not supported.
• SCSI hard disks were tested only in VMware virtual machine.
• It is unknown how mbldr works in configuration with RAID.
• I don't know whether it works with LVM.
• Microsoft Windows "dynamic disks" technology is also not tested yet.
• Mbldr is unable to load and run boot records from partitions on another drive (not the same as the one used for loading MBR with this mbldr). Instead try installing mbldr on each hard drive and configure them independently.
• mbldr installation/configuration program does not detect whether the particular partition contains bootable operating system. You may try to boot from any partition even from Linux swap despite it is odd.
• mbldr does not check partition table for errors like standard DOS/Windows MBR does. Neither integrity of binary code of mbldr itself nor partition table values are checked. This is because I have to keep the code as small as possible.
• All information related to "what to boot" and "where to find it" is saved by installation program directly in the internal structures of mbldr. Small assembly code is not intended to search through list of partitions to find the ones suitable for booting (or the one marked "active"). Autodetect of logical disks is also not supported.
• If you are using "Next HDD" option you may experience difficulties trying to boot different operating systems from second HDD (and all others except the first one) since their loaders should respect "hard disk number" input parameter. For example MS-DOS and Microsoft Windows could be loaded from the first hard disk only (which has a number 80h). LILO is able to boot Linux from the second hard disk.
• Mbldr is able to detect either ASCII or scan-codes while being in boot menu. Thus some keys that generate neither ASCII nor scan-codes (like multimedia keys) could not be assigned to boot operating systems from a list.
• GUI version of mbldr configuration utility does not support DOS and Windows 98/ME.

Known issues

1. mbldr does not work with VMware ESX operating system
2. Mbldr can not be compiled with nasm 2.04 and 2.05, need to downgrade nasm to version 2.03.01 or earlier
3. Mbldr 1.45 may hang during boot if system timer is enabled. This is a bug in timer interrupt handling routine, fixed in 1.46. If you experience issues with such hanging, try user-timer option or roll-back to 1.44. You can also try newer versions like mbldr 1.46.
4. It has been reported that mbldr configuration program for DOS hangs at the stage of hard disks detection. The known configuration is one of the modern (as of end of 2008) motherboards with Intel CoreDuo CPU and PATA devices. The workaround for this problem is to use mbldr under Linux or Windows. However detailed reports of similar issues are welcome (not yet fixed as of mbldr 1.46).

Troubleshooting

1. Run the program with "-v" command line switch and send me a log file
2. Do a screenshot of a problematic menu (if the problem is in configuration program)
3. Send me an explanation of sequence of steps (in particular what you type in configuration program)
4. Describe hardware configuration (disks subsystem: number of drives, their types (ATA, SATA, etc.), primary or secondary, sizes, etc.)
5. Report OS version where you execute mbldr configuration program
6. Report the version of mbldr you are using
7. Explain the problem (crash, hanging, incorrect behavior, etc.)
8. Send me a file with custom boot menu text if you use it
9. Describe partitioning scheme of your hard drives (sizes and filesystems on primary partitions and logical disks). Appropriate screenshots of fdisk or PQMagic may help as well.
10. Provide a description of OSes you want to boot: where are they, how many oses you want to boot, what are they (brands+versions)
11. What other boot-related software do you use (other boot managers for example on other hard disk, OS loaders like LILO, etc.)
12. If the problem is in GUI tool, send me a screenshot

Screenshots

Here are some screenshots of mbldr version 1.43:

Mbldr boot menu is shown when PC is powered on or rebooted. Please note that it could easily be customized or hidden:
(It appears on the screen immediately after Power-On-Self-Test (PoST) is passed):

Mbldr boot menu itself

CLI version of mbldr installation/configuration program running under FreeDOS:

Main menu	Adding a partition

CLI version of mbldr installation/configuration program running under Windows 98:

Configuring timed boot

GUI version of installation/configuration program under Windows2000/Vista, FreeBSD and Linux:

Under Windows 2000	Under Windows Vista	Under FreeBSD with GTK	Under Linux with X11

Of course mbldrgui also works fine under Windows XP and looks similar to Windows 2000 and Vista. Also please note that under Linux/BSD it is recommended to use wxGTK engine of wxWidgets since X11/Universal works quite kludgy (at least for wxWidgets 2.8.3).

Features

• May boot up to 9 operating systems from primary partitions or logical disks in custom order (including chainload feature)
• MBR boot loader is written in Assembly language and compiled with NASM
• Installation/configuration program is written in C language and compiled with free tools (DJGPP under MS-DOS or FreeDOS; GCC under Linux and BSD; MinGW under Windows)
• Installation/configuration program could be run under MS-DOS or FreeDOS and requires DPMI extension. Since mbldr 1.38 Linux and BSD are also supported. Since 1.39 Windows is also supported.
• Uses text-mode for both boot and installation/configuration modes
• Supports MBR backup/restore operations with partition table checks
• Supports user-defined boot by pressing a configurable key ("1", "2", etc. or "F1", "F2", etc.) and showing boot timer activity in a form of progress-bar
• Supports switching of an active flag on primary partitions
• Supports boot timeout with loading of the default operating system (which is also configurable)
• Fully customized boot menu indicating timer and default operating system
• Supports booting of the operating systems which reside above 1024 cylinder
• Hiding of inactive primary partitions (for FAT/FAT32/NTFS) like it is done in PQ PartitionMagic/OS-2 Boot Manager (i.e. only the partition being booted is visible, all others are hidden). This is done to prevent problems happening with MS-DOS and Microsoft Windows when living simultaneously on one hard disk. Please note that if you boot an operating system from logical disk all FAT/NTFS primary partitions will be marked invisible and inactive.
• Detects most modern partition types properly (including hidden ones, NTFS, Linux native, LBA partitions, etc.)
• It fits into first 446 bytes of a 1st sector on a hard disk, not requiring separate partition to be allocated
• Supports all kind of hard disks supported by BIOS: ATA, SATA and SCSI
• Customizable interrupt key of a boot timer. It may be useful if the default <Esc> conflicts with a hot-key reserved by BIOS
• Development and packaging of mbldr requires only free software: FreeDOS, DJGPP, GCC, InfoZIP, NASM, UPX, wxWidgets, etc.
• May be installed on any of the available HDDs found in a system
• The installation/configuration program has multilanguage interface

Download

Original release (1.35) of OS-BS project has been branched to create first official version (1.36) of mbldr (please note, that versions of mbldr below 1.36 do not exist).
The changelog for each version is available inside each package. However, the latest changelog is available here. For complete set of files available for download, look here.

ToDo

1. Automatic detection of difference between partition tables in main MBR and chainloaded copy of MBR. Need to suggest user to keep them in sync every time the difference is found (at configuration time, not at boot time).

Help needed

1. Starting from version 1.44 mbldr became localizeble. This means that user interface of graphic and text-based console configuration programs can be translated to other languages. Since I am Russian native speaker, it is very difficult for me to support anything except Russian and English. So I posted new open position to "Help wanted" section on the sf.net web-site which asks for new translations. But of course updates to existing translations are always welcome.
   Here are basic guidelines and hints for making and updating translations:
   • Mbldr uses gettext() interface (with .mo and .po files), thus no source code modification is needed at all
   • There is no requirement on skills in C programming language for translator
   • You don't need to recompile mbldr sources when you add or modify translation-related files. Hence you don't need compilers and SDKs. No need to follow building-related steps. There is only one exception - msgfmt utility used to convert po-files to mo-files (compile translations)
   • Both GUI and text-based console configuration programs use one united translation file per language to get localized strings. There is no need to translate same sentences twice. Thus every time you update a translation it may affect both configuration programs.
   • There are only two tools you need to translate strings: the UTF-8 capable text editor and msgfmt utility to compile translations.
   • You may use any operating system to create new or modify existing translation. It could be Windows, Linux or even MS-DOS (if there are UTF-8 aware text editors).
   • You need to download the latest release of mbldr package (even if it is marked as "Unstable"). There is no difference, which OS it is targeted for - DOS, Windows and Linux/BSD packages are fine.
   • I recommend VIM or GVIM as a free UTF-8 aware text editor
   • The result of your work should be new (or existing, but updated) .po file. You should send it to me by e-mail, in compressed form (either zip or gzip or bzip2). Also please provide me with your name - I would like to inform mbldr users about author of new translation. Please note, the po-file must be in UTF-8 encoding.
   • When making new translations you should take ru.po file from po/ directory and modify it accordingly. My goal is to keep Russian translation up-to-date with all current strings used in latest version of mbldr, so Russian po-file always has complete set of required strings.
   • Your translation must be covered with BSD-license.
   • When you finish updating po-file you should generate proper mo-file (a binary compiled translation). This should be done with msgfmt program. The command line for compilation is "msgfmt ru.po -o ru.mo". The resulting mo-file should be placed into "mo/ru/LC_MESSAGES" directory. Here "ru" should be replaced with the shortened form of language you are working on. Refer to Language codes to determine the abbreviation you need (usually called "locale").
   • Please note that Windows version of mbldr configuration utilities searches for available translations in current directory, thus "mo/ru/LC_MESSAGES" should appear in the same directory where mbldr utilities reside. The same is applied to MS-DOS, but since long file names are not supported LC_MESSAGES should be replaced with LC_MESSA (not LC_MES~1). For Linux the path used to store translations is usually "/usr/share/locale/ru/LC_MESSAGES", but this usually depends on the installation prefix of mbldr package.
   • For MS-DOS msgfmt utility could be found on DJGPP web-site. Go to downloads section, choose one of the available mirrors, then download latest gtxtXXXb.zip package (for example gtxt040b.zip in "current/v2gnu" directory)
   • For Windows msgfmt utility could be found on MinGW web-site. Go to downloads section, then choose Sourceforge downloads, then download latest gettext-X.XX.X-X-bin.tar.bz2 package (for example gettext-0.16.1-1-bin.tar.bz2 in "Technology Preview: Tools for MSYS-1.0.11" from "MSYS Supplementary Tools" section).
   • For Linux msgfmt utility could be either installed using package manager from your distribution (usually belongs to gettext package) or compiled from source. In the latter case you need to download the package from (one of GNU mirrors).
   • The structure of po file is described here
   • When doing translation please leave printf-specific and other special character-sequences intact in translated strings. In particular take care about stuff like "\n", "\r", "%s", "%i", "&" (used for hotkeys), etc.
   • Case of letters should be kept untouched, trailing spaces, commas, colons, and all other symbols should be kept as well
   • Lines should be terminated with 0x0A only (Unix style). 0x0D-0x0A (DOS/Windows style) could also work, but better to keep the line-ends consistent across all available translations
   • If you deal with DOS version of mbldr under Windows 98/ME you probably will need to manually restore long name of LC_MESSAGES directory from LC_MESSA which fits into DOS-limitation.
   • If you see English interface instead of the one you expected there could be several reasons of that. One common reason applicable to all platforms is that mbldr could not find language resources (mo-files) where they should be. For Windows you may need to specify proper locale in Regional Settings (in Control Panel). For DOS you may need to load country.sys driver in config.sys (country=007,866,c:\country.sys for Russian). This is needed to properly set locale and codepage. For DOS you may also need to load fonts into video-memory (for Russian this could be done for example with keyrus utility - usually launched from autoexec.bat). One common method (for all platforms) to force mbldr to use the language you want is to set one of the following environment variables: LANG, LC_MESSAGES or LC_ALL. This could be done in bat-file or a shell-script prior to launching mbldr iself. Russian example for MS-DOS is: set LANG=ru (only language) or set LANG=ru_RU.CP866 (language and encoding). LC_MESSAGES overlaps LANG, LC_ALL overlaps all of them.
   • If you have questions, contact me using "Translation and localization" forum on sourceforge project site. Please don't do work on translation before contacting me. I would appreciate any help, even with incomplete translations. Do not hesitate to ask about technical details if you are not familiar with translation procedure - I explain everything you need to make the work fast and efficient. Looking forward to work with you.
2. It is needed to perform intensive testing on different hardware and software platforms and configurations
3. Mbldr needs help in attempts to be compiled on different "non-standard" software configurations and operating systems
4. Help in testing how HDD model/vendor detection mechanism works is also needed under different operating systems (especially different flavor or *nixes), with different controllers and hard disks Also you can take a look on ToDo section if you want to help with something else.

Translation status

Building instructions

Building under Linux and BSD-flavours

1. Download the latest mbldr.tar.bz2 package to your local machine
2. Untar and decompress it with "tar jxf mbldr.tar.bz2" command
3. Minimal requirements for the building tools are: gcc, ld, nasm and xxd (is a part of vim package). You may also need strip, upx, ndisasm, tar and install. To build GUI version you will need installed development version of wxWidgets (including headers and libraries), g++ and wxrc (is a part of wxWidgets utilities).
4. Invoke "./make_unix.sh" shell script or simply type "make". Please note that under BSD you need to use "gmake" instead of "make", so "./make_unix.sh" most probably will not work. Also please note that if you don't want to build GUI version of mbldr configuration program (or if you simply don't have wxWidgets) type "make mbldrcli" (similarly you may build only GUI version with "make mbldrgui").
5. Be sure there is no compilation-time and linking-time errors on the screen
6. To prepare Linux/BSD source-distribution package (similar to what you have downloaded) type "make dist" (you don't need this step, it is only for maintainers)
7. To clean temporary object files and binary executable files type "make clean" (please note that "make distclean" is not implemented)
8. To install/uninstall binary and documentation you may use "make install" or "make uninstall" respectively. The target directories are defined by DESTDIR and PREFIX environment variables so it is usually /usr.
9. To begin using mbldr configuration program type "./mbldrcli" or "./mbldrgui". Append "-h" command-line switch to get on-line help.

Building under DOS and old Windows

1. DOS-version of mbldr supports command-line interface only (the binary is called mbldr.exe). Same binary should be used under Windows 98 and Windows ME
2. Use MS-DOS or FreeDOS. I use "0.84 pre" version of FreeDOS, any newer version can also be used.
3. Make sure cwsdpmi.exe is located in the directory listed in PATH environment variable (for example c:\tools\)
4. Unzip all DJGPP archives (binary packages of bnu2161b, djdev203, gcc410b, gtxt040b, licv111b, mak3791b, rhid15ab, txi48b, fil41b) to c:\djgpp\ folder (uze unzip32.exe binary shipped with DJGPP to uncompress). You can use ZIP-picker for this and browse FTP folders on DJGPP web-site
5. Make sure c:\djgpp\bin and c:\tools are in your PATH environment variable
6. Add DJGPP environment variable to autoexec.bat and reboot ("set DJGPP=C:\DJGPP\DJGPP.ENV")
7. Unzip upx.exe, xxd.exe (from VIM package for DOS), nasm.exe, ndisasm.exe, zip.exe (from InfoZIP package for DOS) from appropriate DOS packages to c:\tools\
8. Go to the folder where you have unpacked sources of mbldr
9. Type make_dos.bat

Building under NT-family of Windows

1. Similarly to Linux/BSD you may build either mbldrcli or mbldrgui or both. The requirements for GUI version are little bit more complex
2. Download the latest mbldr.zip package to your local machine (please note that you need Windows zip-package. If you have downloaded zip archive for DOS, you will not be able to build Windows version)
3. Unzip the package with the help of free InfoZIP or 7-ZIP archivers (under Windows XP you may use built-in ZIP decompressor - right-click on archive and choose "Extract all" item from context-menu)
4. Install a recent GCC (gcc-core), binutils and mingw-runtime from MinGW web-site (you need to download binary packages from current/release branch and then unpack it to c:\mingw\ directory with the help of 7-ZIP archiver). Please note that if you are using Microsoft Internet Explorer it tends to rename .tar.gz archives to strange .tar.tar combination, so you need to rename them manually.
5. Add c:\mingw\bin\ path to the %PATH% environment variable (this could be done using System applet in Control Panel, where you need to choose Advanced tab and then Environment Variables)
6. Install GNU make package from MinGW web-site (it is distributed as executable, so there is no need to unpack it manually) Again, the target directory should be c:\mingw
7. Install nasm into the same directory by unpacking zip archive (choose Win32 binaries in the download page). Check that nasm binaries appear in c:\mingw\bin directory.
8. Install vim, the easiest way to do it is to install gvim package which is distributed as a Windows executable. Mbldr requires only xxd utility, so you need to copy xxd.exe from c:\Program Files\Vim\VimXX\ to c:\mibgw\bin\ directory (where XX is a version ov vim/gvim).
9. Download Windows 32 API package from MinGW web-site and extract it in the same way.
10. Download Libiconv and Gettext (can be found in section of MSYS Supplementary Tools) bin and dll packages from MinGW web-site and unpack them all to c:\mingw directory (please note that contents of /usr/local/ folders in archives should appear directly in c:\mingw\ for all 4 packages).
11. You may also want to compress the result mbldr binary with UPX compressor (this is optional). Download the Win32 console version of compressor and unzip in into c:\mingw\bin\ (in fact you need only upx.exe file).
12. Invoke a command-line interpreter (click on "Start" button, then "Run...", then type "cmd" in the edit-field) and switch to the directory where unpacked files of mbldr have been stored (this can be done with "cd" command)
13. Type "make_win.bat mbldrcli.exe" to build command-line version of mbldr. If you don't need GUI version this is a last step. Store mbldrcli.exe somewhere and remove all intermediate directories (c:\mingw\, etc.). Roll-back changes in your %PATH% environment variable
14. If you want to build GUI version of mbldr you need to download and compile wxWidgets library. There are several ways to perform wxWidgets compilation, I recommend to use MSYS and MinGW as described in wxWiki. wxWidgets is written in C++, so you need to download and extract G++ (gcc-g++) compiler from MinGW web-site.
15. It is also needed to simulate Unix environment. It could be done with MSYS - install it from MinGW web-site (you need the main MSYS package, not the developer's toolkit). Use default target directory for installation (c:\msys\1.0\). In the console window that appears after MSYS installation process you need to agree to perform port-installation configuration steps. Then point it to c:/mingw/ directory (not c:/mingw/bin/). Note the type of slashes - these are forward in Unix-style.
16. Update your %PATH% environment variable with c:\msys\1.0\bin\. Please note that MSYS path should be after MinGW path.
17. Download wxMSW package in the form of executable from the wxWidgets web-site (Microsoft Windows port of wxWidgets library). Install it into default directory.
18. Define new environment variable %WXWIN%. It should point to a directory where wxWidgets is installed (for example "c:\wxWidgets-2.8.4"). This should be done in the same way as for %PATH% environment variable. Please note that command-line interpreper should be reopened to use newly added environment variables.
19. Run MSYS shell in a console window (using the desktop icon) and switch to wxWidgets directory using command like "cd c:wxWidgets-2.8.4/". Please note that there is no slash or backslash after disk specification ("c:").
20. Use "./configure --enable-monolithic" script to adjust Makefiles. You may pass some parameters in order to enable or disable debugging, reduce the size of result binary by switching off some components, etc. For wxWidgets 2.8.4 I use "./configure --enable-monolithic --disable-shared --enable-optimise --disable-debug --disable-mem_tracing --disable-profile --enable-no_rtti --disable-no_exceptions --disable-compat24 --disable-compat26 --enable-image --enable-gif --disable-pcx --disable-tga --disable-iff --disable-pnm --disable-xpm --disable-icocur --without-libpng --without-libjpeg --without-libtiff --without-libxpm --without-libmspack --without-opengl --without-regex --without-zlib --without-odbc"
21. If the previous step was completed successfully, use "make" to build the wxWidgets library.
22. There is no need to invoke "make install", instead check (and update if necessary) values of CXXFLAGS and LIBRARIES variables in Makefile.win file (which is a part of mbldr distribution package). You may do it with vim or gvim that you have recently installed.
23. If you want to create a Windows package of mbldr (in zip-archive) you need to install InfoZIP. Download ZIP (not UnZIP) utility and unpack zip.exe binary into c:\mingw\bin\ folder.
24. Run command-line interpreper, switch to directory with mbldr sources and type "make_win.bat mbldrgui.exe" to build GUI version of mbldr configuration utility. You may also invoke "make_win.bat" without parameters to build both mbldrcli and mbldrgui.
25. Copy mbldrgui.exe file to some place, uninstall unused software and wipe intermediate directories out. Also don't forget to restore your %PATH% and delete %WXWIN% environment variables.

Contacts

Current maintainer of mbldr is Arnold Shade (what is a nickname due to several reasons being anonymous). Use it to refer mbldr 1.36 and above.

• arnold_shade __at__ users __dot__ sourceforge __dot__ net

The author of OS-BS is Thomas Wolfram. Use it to refer os-bs 1.35 and below (which is also called mbldr 1.35):

• Thomas __dot__ Wolfram __at__ BootManager __dot__ com
• thomas __at__ aeon __dot__ in-berlin __dot__ de
• thomas __at__ wolfram __dot__ net
• wolf __at__ prz __dot__ tu-berlin __dot__ de

Note: you need to replace " __dot__ " with "." and " __at__ " with "@" before using the addresses above.

Links

• Site at sourceforge
• Freshmeat page

Pages related to OS-BS project:

• Old page made by Thomas and archived by web.archive.org
• Old releases of OS-BS at FreeBSD FTP site

Similar projects (other boot managers):

• MATTsoft Boot Manager
• XBOOT Multi Boot
• Smart Boot Manager
• GAG, the Graphical Boot Manager
• Ranish Partition Manager and XOSL Boot Manager
• mbrbm (Master Boot Record Boot Manager)
• Partita
• BOOTEASY

• Intel 80386 Programmer's Reference Manual
• Intel 80386 Programmer's Reference 1986
• NASM (Netwide Assembler) and NASM Manual
• A general NASM guide for TASM coders and other ASM people

• How It Works: Partition Tables
• Boot Records Revealed!
• Partition types

• DJGPP - complete 32-bit C/C++ development system for Intel 80386 (and higher) PCs running DOS
• Info-ZIP is a free, portable, compressor-archiver utilities compatible with the DOS-based PKZIP
• 7-Zip is a file archiver with a high compression ratio
• UPX is a free, portable, extendable, high-performance executable packer
• MinGW is a collection of freely available Windows header files and libraries combined with GNU toolsets
• Cygwin is a Linux-like environment for Windows
• wxWidgets gives you a single, easy-to-use API for writing GUI applications on multiple platforms that still utilize the native platform's controls and utilities
• Vim is an advanced text editor that seeks to provide the power of the de-facto Unix editor 'Vi', with a more complete feature set.

• FreeDOS - nice complete alternative to commercial MS-DOS operating system
• ReactOS is an advanced free open source operating system providing a ground-up implementation of a Microsoft Windows XP compatible operating system

• Technical Committee T13 (AT Attachment)
  • BIOS Enhanced Disk Drive Services - 3 (EDD-3) and local copy
  • AT Attachment with Packet Interface - 6 (ATA/ATAPI-6) and local copy
• Phoenix Technologies
  • BIOS Boot Specification Version 1.01 and local copy
  • Enhanced Disk Drive Specification Ver 3.0 and local copy