Re: Debugging an (unsuccessful) prodos boot

[Scott Hemphill <hemphill@hemphills.net>]

BLuRry <brendan.robert@gmail.com> writes:

> I'm in the midst of debugging a very hard problem.   Trying to
> determine why Prodos is unwilling to start.  It relocates, then reads
> the root volume.  No other MLI calls are made, and it spits out a
> relocation error.  The filesystem is a large prodos volume with only a
> few files in it; though it is most likely that the volume header block
> was written incorrectly somehow.
>
> The volume block is as follows:
> 00 00 00 00 e5 2e 4a 41 43 45 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 dc 00 01 19
> 19 00 03 27 0d 0b 00 06 00 ff ff 18 53 45 54 54
> 49 4e 47 53 00 00 00 00 00 00 00 06 00 00 01 00
> 10 00 00 b0 00 0a 13 19 00 ff 00 03 b0 00 0a 13
> 02 00 2e 53 59 53 55 54 49 4c 2e 53 59 53 54 45
> 4d 00 ff 01 00 01 00 0e 03 00 b0 00 09 25 19 00
> ff 00 20 b0 00 09 25 02 00 24 55 54 49 4c 00 00
> 00 00 00 00 00 00 00 00 00 00 03 00 01 00 00 ab
> 00 b0 00 09 2c 19 00 ff 00 09 b0 00 09 2c 02 00
> 2c 42 41 53 49 43 2e 53 59 53 54 45 4d 00 00 00
> ff 04 00 01 00 00 28 00 b7 00 10 30 19 00 ff 00
> 20 b7 00 10 30 02 00 2f 46 41 53 54 43 4f 50 59
> 2e 53 59 53 54 45 4d ff 05 00 01 00 56 4e 00 b8
> 01 0f 2a 19 00 ff 00 20 b8 01 0f 2a 02 00 2f 4c
> 41 55 4e 43 48 45 52 2e 53 59 53 54 45 4d ff 16
> 00 01 00 2c 1d 00 b8 00 0a 31 19 00 ff 00 20 b8
> 00 0a 31 02 00 26 55 54 49 4c 2e 31 00 00 00 00
> 00 00 00 00 00 06 17 00 01 00 b0 79 00 b0 00 0a
> 13 19 00 ff 00 0e b0 00 0a 13 02 00 24 55 54 49
> 4c 00 00 00 00 00 00 00 00 00 00 00 00 18 00 01
> 00 85 04 00 b0 00 09 2e 19 00 ff 00 04 b0 00 09
> 2e 02 00 25 43 4c 4f 43 4b 00 00 00 00 00 00 00
> 00 00 00 00 19 00 01 00 59 1e 00 ba 80 17 1f 19
> 00 ff 00 00 ba 80 17 1f 02 00 17 43 4f 50 59 2e
> 4d 45 00 00 00 00 00 00 00 00 fc 1a 00 01 00 24
> 00 00 ae 00 0e 33 19 00 ff 01 08 ae 00 0e 33 02
> 00 26 50 52 4f 44 4f 53 00 00 00 00 00 00 00 00
> 00 ff 1b 00 01 00 e8 42 00 ba 00 11 0a 19 00 ff
> 00 20 ba 00 11 0a 02 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

I haven't seen a 32MB ProDOS filesystem formatted this way before.  The
volume directory and the bitmap are at their usual places (block 2 and
block 6, respectively) but the volume directory is limited to a single
block (maximum of 13 files at the top level) and the files are allocated
starting at block 0, weaving around the directory and the bitmap.  Since
blocks 0 and 1 are occupied by the files SETTINGS and SYSUTIL.SYSTEM,
there are no boot blocks present and this filesystem should not be
bootable.  How are you booting it?

[snip]

Scott
-- 
Scott Hemphill	hemphill@alumni.caltech.edu
"This isn't flying.  This is falling, with style."  -- Buzz Lightyear