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I have written a simple bootloader for x86 using NASM and it was converted into boot.bin,i wrote first logical sector of USB Pendrive using dd(in Windows, downloaded from chrysocome site) but it is not taken when i try to boot with actual PC(used Dell labtops),should i write it in physical first sector?

Prabakaran
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  • In the second have of [this SO answer](https://stackoverflow.com/a/36052385/3857942) there are instructions on using Chrysocome _DD_ to do this on Windows. – Michael Petch Aug 16 '17 at 06:52
  • You also have to be aware that on real hardware how the BIOS options affect things. I'd recommend making sure that your BIOS boots on the Pen drive as USB Floppy emulation. With floppy emulation you then need to make sure that your boot sector has a [BIOS Parameter Block](https://en.wikipedia.org/wiki/BIOS_parameter_block) . An example of a DOS 4.0 compatible BPB in NASM can be found in my other [SO Answer](https://stackoverflow.com/a/43787939/3857942) . Without a proper BIOS parameter block many modern OSes will not identify it as bootable even if marked at the end with 0xaa55 .' – Michael Petch Aug 16 '17 at 16:57
  • i tried with BIOS Parameter as you told ,it is not working,earlier i tried in Dell Latitude laptop ,it worked (without Bios parameter),but it is not working in Dell vostro and Inspiron laptops,i think it is not booting into legacy BIOS modes,by default it is taking UEFI,i need to follow rules for UEFI. – Prabakaran Aug 17 '17 at 07:51
  • You need to update the question with your actual code for me to know if there is a bug in your code or another problem. – Michael Petch Aug 17 '17 at 10:21

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