Re: [SeaBIOS] First access to the block drive

On Thu, Mar 01, 2012 at 05:39:25PM +0900, Daniel Castro wrote:
Hello all,
The xen pv drivers are almost done.
When I start the booting process from hda seabios tries to read lba at 0 (sector 0) buffer (buf_fl) to 7c00 count 0 operation 0 (read) command 1 (unlisted) I do not understand count 0 and command 1. Should it be count 1, for the first sector on the drive and a command such as listed in drive.h?
Is this normal? Am I missing something?
I don't understand what you are reporting/asking. The code at boot.c:boot_disk() issues a legacy bios read (int 13 ah=2) of the first sector (count=1). -Kevin

On Mon, Mar 5, 2012 at 4:18 AM, Kevin O'Connor <kevin@koconnor.net> wrote:
On Thu, Mar 01, 2012 at 05:39:25PM +0900, Daniel Castro wrote:
Hello all,
The xen pv drivers are almost done.
When I start the booting process from hda seabios tries to read lba at 0 (sector 0) buffer (buf_fl) to 7c00 count 0 operation 0 (read) command 1 (unlisted) I do not understand count 0 and command 1. Should it be count 1, for the first sector on the drive and a command such as listed in drive.h?
Is this normal? Am I missing something? Thanks for the response Kevin, I am debugging the operation on a xen drive. Right now the drive fron end is initialized correctly and connects to the back end, then boot proceeds. But on the first operation is am getting an command=1 and count=0.
And that seems awkward. I will take a look at boot_disk() to trace the call.
I don't understand what you are reporting/asking.
The code at boot.c:boot_disk() issues a legacy bios read (int 13 ah=2) of the first sector (count=1).
-Kevin
Thanks, Daniel -- +-=====---------------------------+ | +---------------------------------+ | This space intentionally blank for notetaking. | | | Daniel Castro, | | | | Consultant/Programmer.| | | | U Andes | +-------------------------------------+
participants (2)
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Daniel Castro
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Kevin O'Connor