[Coco] [COCO] Putting NitrOS-9 boot track in ROM

[Allen Huffman]

> On Feb 2, 2015, at 11:02 AM, David Ladd <davidwladd at gmail.com> wrote:
> 
> I also tried os9gen with the -q=bootfile
> Sadly nothing happened other than my device booted from old boot file
> I also tried os9gen with the -q=bootfile /dd
> Sadly this option left a temp file in the root of /dd and system no longer
> booted.

DO NOT USE os9gen or cobbler on any hard drive with geometry that doesn’t look like a big floppy disk. It will not work, as best, or do bad things to your drive, at worst. 

IF your hard drive is set up as 18 tracks per sector, single sided, it should work but you’d have a small hard drive.

If the drive is too large, it fails in other ways. It allocates memory for the size of the DAM. My DAM is $FFFF and it tires to allocate “$FFFF+256” which rolls over and only gives it 256 bytes and … bad things happen.

I gen mine manually for now until I write a tool that works like os9.exe.

I use a short B09 program to copy the boot sectors $264-$275 from one HD to the new one, then I use dEd to set bits in the DAM to mark those sectors used. Basically:

Offset $143 - $0F (00001111)
Offset $144 - $FF (11111111)
Offset $145 - $FC (11111100)

Then I copy OS9Boot over, and use dEd to mark where it starts and the size. I get the start and size from “dir -e”. But, where “dir’ shows the file start is actually where the File ID sector is. If it’s a clean drive, OS9Boot is right after it. On mine, the dir said OS9Boot was at sector $88. If I open up dEd and jump to sector $88, I see the File ID for it, and in the segment list, the first segment used is $89. That’s the one I want.

Offset $15-$17 - 3 byte starting LSN (not what DIR reports, but what sector that File ID sector points to)
Offset $18-$19 - 2 byte size of OS9Boot (from “dir -e”)

After that, just having sysgo, CMDS/shell, etc. is all it takes. I use dsave just like normal boot disks from there on out to copy over CMDS, SYS, DEFS, startup, SysGo, etc.

As soon as I get done with all my archiving, I’ll spin out a real quick assembly boot maker.

		— A