- #NO BOOTABLE MEDIUM FOUND VIRTUALBOX WINDOWS 7 CODE#
- #NO BOOTABLE MEDIUM FOUND VIRTUALBOX WINDOWS 7 ISO#
Now when I use your image the error No bootable medium found! System halted no longer appears. I have placed fa as the first byte int the bootloader. The resulting file now looked like: v- CLI instructionĠ0200000 fa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55Ġ02001f0 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 55 aa I then used hexedit and placed a CLI opcode (0xFA) as the first byte of the sector. Running with that change alone didn't work. One way to test whether 0xAA55 at the end is enough by itself I used hexedit and modified your 1.vdi file to look like this: 00200000 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55Ġ0200010 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55Ġ02001f0 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 55 aa <- Corrected signatureĠ0200200 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 aa 55 Failure to find such instructions (examples often include things like JMP, XOR, CLI, MOV) may cause it to think that it isn't valid boot medium. Some BIOSes may search for certain instructions in the first few bytes that are typically found in bootloaders. Valid boot medium may be more than just getting the boot signature correct. 0xaa55 as a WORD is stored with the bytes reversed. This output suggests to me that you reversed the bytes of the boot signature in your file. When added to a virtual machine under VirtualBox I get this on the display:
VBoxManage convertfromraw 1.raw 1.vdi -format VDI Place the bootloader boot.bin at beginning of file 1.raw without truncating the rest of file: dd if=boot.bin of=1.raw conv=notruncĬreate a VDI image called 1.vdi from 1.raw: rm -f 1.vdi I then use this command to create the bootloader file boot.bin: nasm -f bin boot.asm -o boot.binĬreate a 2MiB disk image file 1.raw: dd if=/dev/zero of=1.raw bs=1024 count=2048 Fill out to 510 bytes and add boot signatureĭw 0xAA55 add boot signature at the end of bootloader The example below creates a simple bootloader creates a 2MiB raw image places the bootloader in the raw image and converts the raw image to a VDI. But at a minimum you'll need to place 0xAA55 in the last 2 bytes of the master boot record. You don't provide a minimal complete verifiable example showing a bootloader and how you get it into a VDI. Is there any way to solve this? Why is my virtual disk still not bootable? Edit So, I suppose it now means that the disk is bootable (because at the end of first sector is still signature 55 AA).
Then, I basically filled from that address to the end of VDI file with pattern 55 AA. So, I found that data starts at some address (in my case it is 0x00200000 from the start of the VDI file). So, the start of VDI represents a header and the the rest is actual data stored on virtual drive. I was researching how VDI works and I found that it is usually dinamically allocated and that only the beginning of data is stored.
#NO BOOTABLE MEDIUM FOUND VIRTUALBOX WINDOWS 7 CODE#
So, I decided to put the binary machine code of my OS to virtual hard drive ( VDI file) and then set it to the top of boot order and load it instead of loading from virtual optical drive ISO.
#NO BOOTABLE MEDIUM FOUND VIRTUALBOX WINDOWS 7 ISO#
I don't want to convert my binary file to ISO every time. So, that is a lot of work I want to avoid. I found that I must compile C code to binary format, extract text section and save it as a file, then convert it to ISO, then mount it to virtual optical dive of diskete and then load my OS in VirtualBox. I am creating an operating system in assembler and C. I read all of them, but none of them answers my problem. There are a lot of question on stackoverflow with the similar title.
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