> The advent of nano-X and graphics under ELKS, together with this discusion
> has set me thinking more seriously about ROMing ELKS.
>
> In the bath last night (as always) I thought about how I could modify ELKS
> so it would run without a filesystem, and came up with a way of storing
> binary images in an area of ROM. The ROM would simply contain all the
> binaries in minix format concatenated together, the header of each aligned
> to a 16 byte boundary. The unused field of the header could contain a
> 4 character unterminated string which identifies the binary.
>
> exec would then be recoded to search this area of ROM for the binary in
> question, leaving the text segment and running it in place. The
> initialised
> data would then have to be copied into RAM, but very little RAM would be
> required as only the kernel and program data segments would need to be
> stored there.
>
> Any thoughts anyone?
>
> Al
[<Simon Wood>]
Hi Al (and others),
my thoughts were along a similar approach. But I feel that the ROM File
System should integrate with the VFS and allow the storage of any type of
file. We know that the contents are NOT going to change (it's ROM!!) so
perhaps we could used a small area as a Fixed-FAT that could reference the
individual items on the drive.
Providing the ROM area was mapped into main memory the loader could be made
to create a new data segment and point to the ROM code segment. Perhaps this
would be easiest if the ROM executables were of a slightly different type
(i.e. not true minix), maybe just with a different magic number. As building
the ROM filesystem image would be a one off task, it wouldn't be too much to
do a conversion from minix to special
This sort of thing could also be applied to a RAM only system, for example
the Psion 3a - which I'm doing some work on.
As a side comment about Psion stuff-
I've got a keyboard scanning working and some basic screen stuff, but I need
to find a 'free' bit mapped font to use (probably want 8*13 bits per
character to make it readable, would be really flash if it was anti-aliased
to include a grey and much easier on the eye).
Any suggestions......
Simon W.
