NTLDR uses the ROMBIOS for keyboard and hard disk access during OS
bootstrap so that it can load and process BOOT.INI and then NTKRNL. It
also provides a ROMBIOS disk interface to NTKRNL so that NTKRNL has a
way to load protect mode drivers from the hard disk before any of the
protect mode boot drivers have been loaded and initialized.
After NTKRNL has loaded and initialized all of the boot drivers using
this ROMBIOS interface it can throw away NTLDR and start accessing
everything using the protect mode drivers.
The BIOS is not really done until the OS is just about fully up and
running.
…John
On Tue, 27 May 2003 20:28:09 -0400, “Graham, Simon”
wrote:
>
>The latter; the target has a serial port and some USB ports used for
>kb/mouse and no PS/2 kb/mouse ports.
>
>There remains some confusion (in my mind) concerning the BIOS “legacy USB
>emulation” that might or might not cause this problem; what I do know is
>that the BIOS always uses this and it cannot be disabled.
>
>What I remain confused about is why this can cause problems after the BIOS
>is done and NTLDR is running but does not cause problems after the OS is up
>and running…
>
>/simgr
>
>-----Original Message-----
>From: Phil Barila [mailto:xxxxx@Seagate.com]
>Sent: Tuesday, May 27, 2003 7:37 PM
>To: Kernel Debugging Interest List
>
>“Graham, Simon” wrote in message
>news:xxxxx@windbg…
>
>[snip]
>
>> . As I said, I can’t disable the legacy USB in the BIOS 'cos our only
>> keyboard access is via USB on this system (no steenking PS/2 kb i/f!).
>
>I noticed this earlier, and didn’t jump on it before. How are you debugging
>on a target that doesn’t have a serial port? Or are you saying that it has
>a serial port, but no keyboard or mouse port?
>
>Phil