While trying to get Linux to boot I was remarkably dumb for about 24 hours and then the penny dropped...
Revisiting the BIOS setup screens with a DOM in place I saw that the DOM appeared in the list as the second boot device. So what if...?
I moved the DOM across to another system, fired up Tiny Core, deleted the files on the first partition and then installed Tiny Core 5.2 onto the FAT16 partition and marked it as bootable. I moved the SATA DOM back to the Pulsar, went into the BIOS and changed the first boot device to be the SATA DOM, and rebooted.
Success! ...or was it? I was presented with a screen I don't normally see - a grey screen with the flashing message in the photo.
While I was sitting there wondering what to do next, the screen suddenly changed to the more usual black screen with the messages that Tiny Core spits out as it runs its startup scripts. It booted and ran, albeit with a 55 second delay getting there.
Subsequently I edited the boot parameters to remove the 'quiet' option and found that the delay was occurring when it was probing for the mouse port on the 8042 controller.
Adding the kernel boot parameter i8042.noaux got rid of the delay. I also re-installed Tiny Core onto the SATA DOM after formatting it to the ext4 file system.
BTW: I noticed this line in the dmesg output:
DMI: nVidia PULSAR/To be filled by O.E.M., BIOS 080015 09/29/2009
It goes hand-in-hand with the EVALUATION COPY, NOT FOR SALE in the boot screen!
My interpretation of the Pulsar architecture is that there is lurking somewhere some flash memory that has the core of the Pulsar's operating system. This is the mysterious ROM FLOPPY DRIVE. This normally loads and runs and then mounts the partitions on the SATA DOM to gain its full functionality. My copying the SATA DOM to a USB drive and then removing the SATA DOM just demonstrated that it would search any attached devices for those files. It was not actually booting from the USB drive, the kernel of the operating system was still being loaded from the ROM FLOPPY DRIVE.
George Kourtis also pointed me at an entry in the BIOS under Chipset/Southbridge titled: PXE rom boot support. Changing this to Enabled did result in a new message appearing during the BIOS boot sequence:
"Broadcom NetXtreme Boot Agent v11.9.7"
..but after a few seconds this timed out and, if all other boot options were set to Disabled, I ended up with the error message:
Reboot or Select proper Boot device or Insert Boot Media in selected Boot device and press a key
As far as George and I can determine the Pulsar does not put out any network traffic during the delay so there is no actual attempt to PXE boot.
It would appear that the Pulsar will only boot from the internal ROM Floppy Drive or the internal SATA drive, but not from the USB ports or the network.
In order to run your operating system of choice you'll need to find some way of installing it on the SATA DOM first.
Any comments? email me. Last update July 2014