QNX 6.2 loader question

When I make a boot floppy (fdisk, dinit) from my QNX 6.2 workstation, it
boots just like I want: I get a quick “hit esc for .altboot” message,
then a normal boot.

When I make an OS image for my embedded CPU (my floppy loads stuff onto
the DiskOnChip), I don’t like the boot: I first get a question “Boot
partition 1?” that hangs around for a while, times out, and then does
NOT say “hit esc for .altboot”.

Don’t know much about loaders… can I get my DiskOnChip loader to not
ask me about partitions, but give me the .altboot option?

-Jeff


Jeffrey W Percival, Senior Scientist and Associate Director
Space Astronomy Laboratory, University of Wisconsin - Madison
1150 University Ave, Madison, WI 53706 USA
608-262-8686 (fax 608-263-0361) jwp@sal.wisc.edu
http://www.sal.wisc.edu/~jwp

The DiskOnChip (DOC) pretends to be a hard drive. QNX (like most OSs)
boots hard drives in two stages: a partition loader (“Boot partition 1”)
and then the file system loader (“altboot”).

You can replace the first stage loader with the basic DOS one by running
the DOS/Windows fdisk as: “fdisk /mbr”. Alternatively, just copy the
first 512 bytes from a windows hard drive and drop it into the first 512
bytes of your DOC. The DOS partition loader just boots the partition
marked “boot”, with no messages.

As for the file system loader (all known versions ask for “altboot”), I
assume that it works since you can boot into QNX from your DOC. It’s
strange that it doesn’t ask about “altboot” from your DOC. Maybe a
keyboard keypress got buffered that made the “altboot” message go by?

Daryl Low

Jeffrey W Percival wrote:

When I make a boot floppy (fdisk, dinit) from my QNX 6.2 workstation, it
boots just like I want: I get a quick “hit esc for .altboot” message,
then a normal boot.

When I make an OS image for my embedded CPU (my floppy loads stuff onto
the DiskOnChip), I don’t like the boot: I first get a question “Boot
partition 1?” that hangs around for a while, times out, and then does
NOT say “hit esc for .altboot”.

Don’t know much about loaders… can I get my DiskOnChip loader to not
ask me about partitions, but give me the .altboot option?

-Jeff


Jeffrey W Percival, Senior Scientist and Associate Director
Space Astronomy Laboratory, University of Wisconsin - Madison
1150 University Ave, Madison, WI 53706 USA
608-262-8686 (fax 608-263-0361) > jwp@sal.wisc.edu
http://www.sal.wisc.edu/~jwp

Correction, the partition boot loader lives in the first 446 bytes of
the hard drive. The remainder of the 512 bytes is the partition table
itself.

Daryl Low

Daryl Low wrote:

The DiskOnChip (DOC) pretends to be a hard drive. QNX (like most OSs)
boots hard drives in two stages: a partition loader (“Boot partition 1”)
and then the file system loader (“altboot”).

You can replace the first stage loader with the basic DOS one by running
the DOS/Windows fdisk as: “fdisk /mbr”. Alternatively, just copy the
first 512 bytes from a windows hard drive and drop it into the first 512
bytes of your DOC. The DOS partition loader just boots the partition
marked “boot”, with no messages.

As for the file system loader (all known versions ask for “altboot”), I
assume that it works since you can boot into QNX from your DOC. It’s
strange that it doesn’t ask about “altboot” from your DOC. Maybe a
keyboard keypress got buffered that made the “altboot” message go by?

Daryl Low

Jeffrey W Percival wrote:

When I make a boot floppy (fdisk, dinit) from my QNX 6.2 workstation, it
boots just like I want: I get a quick “hit esc for .altboot” message,
then a normal boot.

When I make an OS image for my embedded CPU (my floppy loads stuff onto
the DiskOnChip), I don’t like the boot: I first get a question “Boot
partition 1?” that hangs around for a while, times out, and then does
NOT say “hit esc for .altboot”.

Don’t know much about loaders… can I get my DiskOnChip loader to not
ask me about partitions, but give me the .altboot option?

-Jeff


Jeffrey W Percival, Senior Scientist and Associate Director
Space Astronomy Laboratory, University of Wisconsin - Madison
1150 University Ave, Madison, WI 53706 USA
608-262-8686 (fax 608-263-0361) > jwp@sal.wisc.edu
http://www.sal.wisc.edu/~jwp

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