[syslinux] [PATCH 1/1] COM32: Add stub functions for directories

[Gene Cumm]

On Wed, Oct 29, 2008 at 8:47 PM, H. Peter Anvin <hpa at zytor.com> wrote:
> Gene Cumm wrote:
>>
>> I may be trying to oversimplify the code in my head but it would seem
>> that file/directory matching is essentially iterating through a
>> directory extraction then testing to see if the extracted filename
>> matches the filename that you are searching for, stopping the
>> iteration if found or continuing the iteration if not.
>>
>
> It is, sort of, but the sad thing is that matching and extracting in a
> way that is accessible to the user are actually two fairly different
> operations when you're dealing with oddball character sets or
> filesystems with weird formatting rules.  VFAT is the worst, by far, in
> this respect.
>
>> When I said that it seemed like the functions exist to do the
>> directory operations, I misused functions and should have said that
>> the code exists.  The pieces of code to be able to understand the
>> filesystem are there but possibly not in a usable manner to be used by
>> such a group of functions and API calls.
>
> That's more of the issue.  I'm not saying they are hugely hard to write
> (modulo character conversion problems), but there is certainly room for
> ugly surprises.
>
>        -hpa

Well, I decided to try at the easiest of functions to implement (I
think), getcwd().  The COMBOOT call returned what I asked for
unfortunately I wasn't looking closely enough at the code the first
time.  From what I can see the syslinux config file is store as a
string (usable by INT 22h AX 000Eh) but the current directory is a
number (I'm assuming an offset to the top of the directory or
something similar; either way, not the value I wanted).