For some projects I would like to work on I need to modify the kernel to
not overwrite certain sections of memory at startup. My problem is that
these items are put in memory before the kernel is loaded so I can not
just allocate the memory using DOS calls (since no MCB chain exists yet).
The specific items are boot time support for non-FAT filesystems (so I
can boot the FD kernel on NTFS and LEAN filesystems), where although I
could place the fs support in the kernel, I really think a TSR/driver
based IFS is the way to go, and use a fd specific boot time API to reuse
the boot sector read logic to load the IFS driver. Instead of a
specific to this, I would prefer a more generic approach to not
overwriting the memory in use (with the option to free/reuse once no
longer needed).
The other item I'd like to eventually get to (probably sometime after I
fix ATAPICDD, so a year or two down the road) is a replacement for the
BIOS int 13h. How does the ontrack and such software work so DOS
doesn't overwrite them? My reason for this is that I have two computers
that could use improved support, one an old laptop [though I may fry it
when I replace its cmos battery] so BIOS does not have a user specified
CHS setting (yeah its that old that only predefined types are available
and it uses a full size standard 3.5inch hard drive)], the other is my
trusty 486 (my primary kernel testing computer). I could put the card I
bought and never used that is supposed to add LBA/modern for the time
IDE support to my 486, but I don't think it will fix the fact that the
BIOS only supports a single IDE channel, so although I have a
functioning CD-ROM on a secondary controller, I am limited to the
primary controller for hard drives.
So any suggestions, are there existing DOS methods that software such as
network stacks for remote booting or disk software to allow large hds to
work with DOS use to notify DOS? if so any pointers to what to look for
when searching. Or any suggestions for a FD specific solution? Should
it just extend/create a extended BIOS data area and replace the code
that DOS uses to detect its existence and size (is this feasible)?
Thanks for you input,
Jeremy
-------------------------------------------------------
SF.Net email is sponsored by:
Tame your development challenges with Apache's Geronimo App Server. Download
it for free - -and be entered to win a 42" plasma tv or your very own
Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php
_______________________________________________
Freedos-kernel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/freedos-kernel
