Invalid partition entry number (another question)

[lweb20]

All right ..

Reformulating my question:

I have problem with the number of partition entry in a bootloader.

VMware return 0x0:0x7CE (ds:si) in a second partition.
VirtualBox return 0x0:0x7BE (ds:si) in a first partition.

As you can see the values ​​are not expected or not I'm interpreting well.

I expected 0x1BE in first partition and 0x1CE in second partition.

Please help me.

References:
http://wiki.osdev.org/MBR_(x86)
http://wiki.osdev.org/Partition_Table

PD. Sorry for my very bad english. I'm not kidding..

[iansjack]

What do you mean "return". What code returns these values?

[Octocontrabass]

or not I'm interpreting well

This is your problem.

When this article says "offset 0x1be, 0x1ce, 0x1de, and 0x1ee", it is referring to the offset relative to the start of the MBR.

[lweb20]

Thanks for the responses.

What do you mean "return". What code returns these values?

At booting VMWare and VirtualBox have these values in "ds:si".

When this article says "offset 0x1be, 0x1ce, 0x1de, and 0x1ee", it is referring to the offset relative to the start of the MBR.

MBR starting in 0x0 (sector zero) right? then relative offset are 0x1BE, ... right? if not, I don't understand.

[Minoto]

MBR starting in 0x0 (sector zero) right? then relative offset are 0x1BE, ... right? if not, I don't understand.

The MBR that FDISK uses is coded to:

• relocate itself to 0x0000:0x0600
• examine the byte at offset 0x1be, 0x1ce, 0x1de, and 0x1ee to determine the active partition

Yes, the MBR is located in sector 0 of the disk. However, the article is talking about the location of the MBR in memory, after it's relocated itself to 0x0000:0x0600. 0x0600 + 0x01be = 0x07be, and so on.

[lweb20]

MBR starting in 0x0 (sector zero) right? then relative offset are 0x1BE, ... right? if not, I don't understand.

The MBR that FDISK uses is coded to:

• relocate itself to 0x0000:0x0600
• examine the byte at offset 0x1be, 0x1ce, 0x1de, and 0x1ee to determine the active partition

Yes, the MBR is located in sector 0 of the disk. However, the article is talking about the location of the MBR in memory, after it's relocated itself to 0x0000:0x0600. 0x0600 + 0x01be = 0x07be, and so on.

Ahh how silly of me. I thought it was the offset on the disk, but it was in the memory. Thank you very much friend. Thank you so much.