---
name: "mkdecbootcd"
section: "1"
platform: "linux"
package: "mkdecbootcd"
version: "0.2"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/mkdecbootcd"
---

# mkdecbootcd(1)

A tool for making CDs bootable on DECstations

## NAME

mkdecbootcd - A tool for making CDs bootable on DECstations

## SYNOPSIS

**mkdecbootcd** *bootfile cdimage* kernel\_entry\
 **mkdecbootcd** -m startsector count *cdimage* kernel\_entry\

## DESCRIPTION

This manual page documents briefly the **mkdecbootcd** command, which generates a DECstation bootsector for an ISO-9660 CD image to allow the creation of bootable Linux CDs for DECstations. To make a CD bootable on a DECstation, execute the following steps:\

- 1\.

  Generate a raw bootfile from an ECOFF kernel by calling "**objcopy** -O binary *linux.ecoff* *bootfile*".

- 2\.

  Get the value of kernel\_entry from the kernel's *System.map* file.

- 3\.

  Master an ISO-9660 CD image containing *bootfile*.

- 4\.

  Mount the CD image via loopback mount (e.g.  "**mount** -o loop,ro /path/to/my/cdimage /mnt/")

- 4\.

  Run "**mkdecbootcd** *bootfile cdimage* kernel\_entry" with

- \*

  *bootfile* being the bootfile IN THE LOOPBACK-MOUNTED CD image  (e.g. /mnt/bootfile)

- \*

  *cdimage* being the CD image file itself (e.g. /path/to/my/cdimage)

- \*

  kernel\_entry being the value of the kernel\_entry label in the kernel's *System.map*. This can be either a decimal value, or (with a 0x prefix) a hexadecimal value

- 5\.

  umount the loopback-mounted CD image

- 6\.

  create a CD from the CD image

Besides letting **mkdecbootcd** determine the values for the bootsector from *bootfile* automatically, you can can call **mkdecbootcd** in manual mode with

**mkdecbootcd** -m startsector count *cdimage* kernel\_entry

and supply the startsector and count values for the bootsector yourself.

Please note that, due to limitations in the firmware, DECstations can only boot from CDROM drives capable of 512 bytes blocksize. Many CDROM drives for the PC market do not support this. If your CDROM drive has a Jumper labeled "512/2048" or "Unix/PC", place it in the "512" respective "Unix" position.\
 For writing the CD, no special features of the CD writer are required, so you can use any CD writer, regardless whether it has support for 512 bytes blocksize or not.

## EXIT STATUS

- 0

  Succesful operation

- 1

  Could not open bootfile

- 2

  Could not get blocksize for bootfile

- 3

  Invalid kernel\_entry value

- 4

  Memory allocation for bootsector failed

- 5

  Could not open cdimage

- 6

  Could not read disklabel

- 7

  Could not write bootsector

- 8

  Invalid startsector value supplied (manual mode)

- 9

  Invalid count value supplied (manual mode)\

## SEE ALSO

**[objcopy(1)](/objcopy/1.md), [mkisofs(1)](/mkisofs/1.md), [mount(8)](/mount/8.md)**\

## AUTHOR

**mkdecbootcd** and this manual page were written by Karsten Merker \<merker@debian.org\> for the Debian GNU/Linux system (but may be used by others). They are licensed under the GNU General Public License (GPL) as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

## CREDITS

**mkdecbootcd** is based on ideas from bootprep.c (C) 1999 by Harald Koerfgen \<hkoerfg@web.de\> and on parts of delo, the DECstation ext2 bootloader (C) 2000 by Florian Lohoff \<flo@rfc822.org\>