Hi Jonathan,
> So, the MTD partitions do not directly map to a kernel or a Linux
> filesystem. The "Q;Q;" blocks are an Amstrad specific way of putting
> data into those partitions, with a type + description associated with
> each one. For example the kernel lives in a Q;Q; block in mtd3 called
> "LINUX". mtd3 also has Q;Q; blocks for LDR (the second stage boot
> loader), and PARMS (the kernel boot parameters).
Agreed. I guessed a 32-byte struct based on various `Q;Q;'s seen.
$ qq() {
> LC_ALL=C perl -0777ne 'print $& while /Q;Q;.{0,32}/g' "$@" |
> hexdump -ve '36/1 "%_p" "\n"';
> }
$
$ qq e3-nand-backup.3
Q;Q;...@............MEM.............
Q;Q;................PARMS...........
Q;Q;....Hf..........LDR.............
Q;Q;.....x..........LINUX...........
$
> The CRAMFS filesystem is in mtd4; Q;Q; block name "LNXFSYS". There are
> 2 of them (I imagine to allow for an active + fallback).
$ qq e3-nand-backup.4 | grep LNXFSYS
Q;Q;................LNXFSYS.........
Q;Q;...6............LNXFSYS.........
$
> There are various other bits of content in mtd4 too - you can see them
> by doing:
>
> hexdump -C e3-nand-backup.4 | grep -A 1 "Q;Q;"
That's where my 32-byte-long guess comes unstuck. A Q;Q; appears within
the structs around LIBC's.
$ qq e3-nand-backup.4 | fgrep -3 .LIBC
Q;Q;..^.. ..........WTL_MAILCON.....
Q;Q;..... ..........WTL_RES.........
Q;Q;..M. ........Q;Q;..... ........
Q;Q;..... ..........LIBC............
Q;Q;..... ........Q;Q;...Q. ........
..WTL_WAV.........Q;Q;..... ........
..WTL_CHUNK.......Q;Q;..$.. ........
$
And so it's out of step for a while. Perhaps there's Q;Q;-formatted
data inside a Q;Q; block, or the last struct in the initial `list' is
shorter and its struct's content indicate that.
$ qq e3-nand-backup.4 | grep -1 ^Q | grep -3 ^-
Q;Q;..... ..........LIBC............
Q;Q;..... ........Q;Q;...Q. ........
..WTL_WAV.........Q;Q;..... ........
--
..M_USERPREF......Q;Q;.....V........
Q;Q;.....1..........M_WTL_WTAI......
Q;Q;.....A..........M_VPARSE........
$
I expect a bit of peering at the words in each struct would spot a
length or similar of each `file's data to save searching through for the
next Q;Q;.
--
Cheers, Ralph.
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