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Questions tagged [mbr]

Master Boot Record: the first sector on disk, containing partition info

A Master Boot Record (MBR) is a special type of boot sector at the very beginning of partitioned computer mass storage devices. The MBR holds the information on how the logical partitions, containing file systems, are organized on that medium.

It identifies how and where an operating system is located, so that it can be bootstrapped.

Wikipedia with full partition table info

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Is it possible to write MBR of a pen drive by any hex editor?

After creating the boot loader, if I copy the bytes of the boot loader and paste it on the 1st 512 bytes of the pen drive using a hex editor, will it work? (Actually I want to learn creating an operating system from scratch.)
Nafis Abdullah Khan
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How can I return x1, y1, x2, y2 from SDO_GEOM.SDO_MBR in Oracle?

I have the requirement to return the MBR of a geometry column in the form of four fields in a record. I need x1, y1, x2, y2. How can this be achieved? Here is my current statement with select rows removed for clarity. I want to return the x1, y1,…
CSharpened
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Why is my Windows 7 installation failing when a new bootable Linux drive is inserted?

Ok so I just got a new SSD for my laptop. I have installed Windows 7 on the SSD and can successfully boot into Windows 7. I took the SSD out and put in the normal hard drive and installed Ubuntu onto it. So now when I add the other SSD back into the…
Steven Combs
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Writing C/C++ Compiler to the MBR to execute source code before Booting up the OS

I am trying to write the full OS independent program on C++. I want to load the program just before booting up the OS (i.e. Windows). I tried to replace the MBR with my simple “Hello World” program, but nothing happens and I lost Partition table of…
Farid-ur-Rahman
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How do I read/write (program) the MBR/VBR of a flash drive?

I'm looking for a method of reading/writing (actually programming) the Master Boot Record (or maybe VBR) of a usb mass storage device. Actually its a flash drive whose MBR I want to program, so that whenever I plug it into any computer, a program…
Rushil Paul
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Minimum Bounding Rectangle calculation in Boost R-Tree

Minimum Bounding Rectangles is a pre-requisite for R-Tree creation. What algorithm does Boost C++ library use for MBR creation given a set of points?
user11233302
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Windows MBR Overritten by linux command dd if=/dev/zero of=/dev/sdb bs=512 count1

I know it's a stupid thing what I have done : In a Linux Virtual machine I did dd if=/dev/zero of=/dev/sdb bs=512 count1 to my external hard disk containing windows Now I Cannot detect the external Hard drive in my windows machine. I thing the MBR…
Fahmi Sahnoun
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Disable writing disk signature to MBR in Windows (Address 01B8, 01BC)

Windows is writting a disk signature (serial number) to the Master boot record, if the two addresses 01B8 (4 bytes) and 01BC (2 bytes) are zeros. You can export the first 512 bytes from the drive with dd. Then open diskmgmt.msc. After that, the disk…
Doe John
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can't run dos MBR

guys.I read MBR from c disk to a memory such as 0:0200H,and then i debug it.however,when i arrive 0:7c18H REPZ 0:7c19H MOVSB i get a message 'CPU error:incorrect opcode.Killing process.' i dont know how to deal with it. any help will be…
jiych.guru
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Bootloader jumping to next boot device

So far I've managed to write a simple bootloader using NASM which prints 'Hello world' and then hangs. This bootloader is 512K long and it's stored in a pendrive's MBR. The BIOS is configured to first boot the USB external device and then the hard…
Bruno Mendívez
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reinterpret_cast/type punning functionality in C with unions

I am trying to write 512 bytes as unsigned char, but read them as fields in a struct. Below is the union I have come up with. typedef union { unsigned char buffer[512]; //512 bytes struct { unsigned char a[446]; …
stackoverflow
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Can every USB stick may be turned into a bootable USB?

I'm about to buy a huge amount of USB sticks in order to install a custom OS in them. Do they need a special hardware configuration to make the MBR section suitable for booting? or just by defining it is enough?
AronNeewart
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Why does this ASM function not print properly?

I am trying to write a little function to print either a null-terminated or fixed-length string in a specific memory location. Here is my code: vbrstart: xor eax, eax mov sp, 0x7a00 mov bp, 0x6000 mov ss, ax mov ds, ax mov…
Wyllow Wulf
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how to determine what sectors of partition are unused?

I have one MBR partition(NTFS) with Windows 8.1 installed on it. I wanna install Arch Linux as the second OS. I need to make new partition from unused space of existing one. Is it possible? If so, how to determine what "start" and "end" sector of…
user2304996
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How to calculate how much size do I need in order to properly make MBR

I know that in the end of Master Boot Record (MBR) there is a magic number that tells BIOS it is the bootloader, And that we need to fill in the amount of bytes left until it is 512 bytes (MBR size), but how can do we calculate the amount of bytes…
Israel peace plan with UAE
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