[SeaBIOS] How to Debug read operation on hda

[Kevin O'Connor]

On Wed, Feb 29, 2012 at 11:22:34AM +0900, Daniel Castro wrote:
> Greeting,
> 
> As part of the xen code for PV-Drivers in Seabios I am trying to boot
> from a PV drive. The two ends are connected, and it should be working,
> but when I try to boot from the harddrive it fails.
> Inside the code I treat the cdrom as a drive, except I register it in
> seabios with the cdrom function, but also it fails to boot from cdrom
> with Error 003.
> This could mean that maybe I am adding the drives incorrectly, or that
> my read/write opertaion is wrong.
> 
> Since the operation runs in 16bit how can I debug it to see what is being done?

I usually debug by adding dprintf statements.  When that's too
painful, I connect gdb to qemu and set break points - the steps for
using gdb are in the README file.  I don't know if there is a similar
way to connect gdb to a xen session.

-Kevin