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Re: System log and format of log entries

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On Wed, 15 Jul 2015 12:34:22 -0400, Benjamin David Lunt <zfysz@fysnet.net>  
wrote:

> "Rod Pemberton" <boo@fasdfrewar.cdm> wrote in message
> news:op.x1s0lnu1yfako5@localhost...
>> On Tue, 14 Jul 2015 12:38:35 -0400, Benjamin David Lunt  
>> <zfysz@fysnet.net>
>> wrote:

>>> If my OS found that there was no floppy disk after boot from the
>>> USB emulated disk, it would, well for a better word, crash.
>>> "I booted from a floppy disk, where did it go?"
>>
>> Ok.  You're saying that if after you booted, the OS couldn't find
>> the boot image, it would crash/halt/hang/panic or somesuch.
>>
>> Can't you load the boot image into a ramdisk?  Is it only 1.44MB?
>
> The case here is that on boot up, while still in (un)real mode
> and using the BIOS, my loader thinks that it is booting from a
> standard FDC floppy drive using INT 13h services.

Is it safe to use the BIOS from unreal mode?

> As soon as I move to pmode, these services are no longer available,
> so I have two (or more) options.  The first, find all actual FDC
> controllers and add their attached drives to the files system
> module.  Compare any disk found to the one we booted from, and
> you have found your booted from disk.
>
> However, what if this disk was a USB floppy drive?  You haven't
> found the booted from disk.  As soon as my OS tried to access
> the booted from disk to load a driver, write a log file, or
> what ever, it couldn't find the drive and crashed.
>
> This was something that I had never anticipated before, nor
> did I have any reason to fix it until recently.
>
> By now, the USB drivers have been loaded so I enumerate the
> various buses.  Once I have found a floppy drive device, I
> can then compare the inserted disk to the boot signature
> disk I booted from.  Problem solved.
>
> Before, I had yet to add the "oops, you didn't find the
> booted from disk" fix.  I always assumed I could find
> it with the transition from (un)real mode to pmode.
>
> I hadn't added the USB Floppy Disk code yet.
>
> Did that answer your question?

No, not really ...

That explains how you solved your issue, and why you kept
asking us about methods of identifying the boot drive over
the past few years.

Instead of tracking down the boot device by serial number,
I think you could possibly do one of two things to *not* need
to locate and use actual "missing" boot drive:

1) load the boot image into RAM and use RAM as the boot drive
2) don't disable USB floppy emulation for the USB device


Rod Pemberton

-- 
Scientist now say we'll experience a mini-ice in 2030.
So, I guess we need more global warming today ...

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Thread

System log and format of log entries "James Harris" <james.harris.1@gmail.com> - 2015-07-14 11:42 +0100
  Re: System log and format of log entries "James Harris" <james.harris.1@gmail.com> - 2015-07-14 11:59 +0100
  Re: System log and format of log entries "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-15 03:23 -0400
    Re: System log and format of log entries "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-15 22:46 -0400
  Re: System log and format of log entries "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-15 03:33 -0400
    Re: System log and format of log entries Peter Cheung <mcheung63@gmail.com> - 2015-07-15 00:47 -0700
    Re: System log and format of log entries "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-15 22:42 -0400
      Re: System log and format of log entries "Benjamin David Lunt" <zfysz@fysnet.net> - 2015-07-16 12:18 -0700
        Re: System log and format of log entries "Mike Gonta" <mikegonta@gmail.com> - 2015-07-16 15:50 -0400
          Re: System log and format of log entries "Benjamin David Lunt" <zfysz@fysnet.net> - 2015-07-16 13:24 -0700
            Re: System log and format of log entries "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-17 06:39 -0400
              Re: System log and format of log entries "Benjamin David Lunt" <zfysz@fysnet.net> - 2015-07-17 10:27 -0700
                Re: System log and format of log entries "Benjamin David Lunt" <zfysz@fysnet.net> - 2015-07-21 16:38 -0700
  Re: System log and format of log entries "James Harris" <james.harris.1@gmail.com> - 2015-07-15 15:15 +0100

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