MS-DOS Boot Program for Plan 9

The program is written by myself and Russ Cox.

Boot performs the same job as b.com, but is an MS-DOS .exe, allowing the kernel and plan9.ini to be loaded from any filesystem accessible by MS-DOS. In addition, the Packet Driver Specification is supported, allowing booting over networks.

The current version is 1.1, and is the first, so please by gentle with it. It can be downloaded here.

How to use

It functions very similarly to b.com, so the manual page is a good place to start. To avoid confusion, the boot methods used are distinct. They are:

dos

Boot from a file in an MS-DOS file system. The syntax is

dos!filespec.

p

Boot via a network using a Packet Driver. The syntax is more flexible here:

p!device[!servername[:filename]]

where device may be either an interface number, or a Packet Driver interrupt, servername is the BOOTP server name, and filename is the file on the server containing the required kernel image.

d

Boot from a Plan 9 partition, using the INT 0x13 interface. The syntax is

d!disk

where disk is the disk number.

Good news

• The program works in the presence of himem.sys, even when extended, upper, or high memory has been allocated by other TSRs.
• If any impediment to the boot process is encountered the boot process is disabled, rather than proceeding to torch the box. The current (non-exhaustive) list of impediments is: processors which are not 386 compatible, Windows 1/2/3.x/95/98/2000/NT (i.e. your executing in a DOS box), protected mode (see Bad News section below), and VM86 mode.

Bad News

• The program does not work in the presence of emm386.exe, or any other TSR which puts the processor in protected mode. Suggestions on how to tackle this will be welcome
• When Windows is shut down to MS-DOS mode, it usually preserves networking support, such that Packet Drivers refuse to load. Again, any suggestions on how to evict the NDIS driver would be appreciated.